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An Archaeometric Study of the 12th Century Ceramics at Hellum PHILIP HANSEN

UNIVERSITY OF SHEFFIELD

05-09-2016

Philip H. W. B. Hansen MA Dissertation 05 – 09-2016

i

Abstract In the period 1983 to 1984, three kilns were discovered in quick succession in Denmark. Due to the

lack of archaeologically proven kilns in Denmark a project for the wider study of kiln and their

products was suggested and carried out. The results were subsequently published in Hikuin 28.

While the results of the publication did manage to show how the Danish ceramic industry changed

over the course of the middle-ages, the work failed to consider the technological aspects of the

ceramics, instead opting to focus on the chronological aspects of the clay.

To work on theseis aspects of study Archaeometric analytical methods were used to study the

chaîne opératoire, using the kiln from Hellum as a case study. Through a combination of visual

examination, x-radiography, and thin-section petrography of the sherds it was possible to show how

the ceramics from Hellum were formed, what materials were used, and how they were distributed.

From the results, it is possible to say that the pots from Hellum underwent a more complicated

production than originally thought, involving molding, coiling, and pulling. It also showed that

through the use of these methods it is possible to place the ceramics in a wider context of

production but also distribution.


ii

Acknowledgements A project of this size cannot possible be undertaken without the help of a large group of people to

help with supervision of the project, acquisition and analysis of materials, and general help with

discussion and writing of the dissertation as a whole.

It of course goes without saying that Dr. Dawn M. Hadley was a great help in terms of

supervising my project and helping with making sure that the scope of the project was kept focused

and doable within the timeframe available for it. In addition, I must thank Dr. Gareth Perry for not

only giving me the idea for the project, but also lending his expertise in all of the lab work and

analysis for the project.

In terms of gaining access to the materials, I would like to thank Stig Bergmann Møller,

Museuminspector at Nordjyllands Historiske Museum, and Christian Vrængmose Jensen,

responsible for archaeological excavations and danefæ at Nordjyllands Historiske Museum.

Because of their help I was able to select sherds for thin-sectioning, as well as obtain two sherds

that are believed to be from Hellum.

In addition, thanks goes out to all the landowners who gave me permission to source clay from

their land. These people are Annemarie Christensen, Mikael Stiil Bach, Esben Wulff Andersen,

Heidi Iversen Mosdal, Esben Knudsen, Gudrun Knudsen, and Henrik Thorlacius-Ussing, Managing

Dirctor of Lindenborg Estate.

While some of the clay sampling was done by me, the final clay samples would not have been

possible without the help of Annette H. W. Hansen and Helena H. W. B. Hansen, who risked their

dryness and tested their rain gear for this project.

Last, but not least, I also must extend a thank you to all of my fellow students who have had to

listen to my project and helped me discuss some of the finer aspects of said project. These are Matt

Lester, Patrick Cropper, William Michael Moody, Louise Olivier Lortie, Benouit Proulx, Viktoría

Halldórsdóttir, and Michael Casimir Mlyniec.

https://www.facebook.com/profile.php?id=577359862




iii

Table of Contents Abstract ................................................................................................................................................. i

Table of Figures and Tables ................................................................................................................. v

1. Introduction ...................................................................................................................................... 1

2. Background, Theories and Methods ................................................................................................ 3

2.1 Theories and Methods ................................................................................................................ 5

2.1.1 Chaîne opératoire ................................................................................................................ 6

2.2 Methodology .............................................................................................................................. 7

2.2.1 Visual Examination ............................................................................................................. 7

2.2.2 X-Radiography .................................................................................................................... 8

2.2.3 Thin-Section Petrography ................................................................................................. 11

2.2.4 Acquisition of Material ..................................................................................................... 15

3. The Hellum Industry ...................................................................................................................... 18

3.1 Kiln and Ceramics .................................................................................................................... 18

3.2 Thin Section ............................................................................................................................. 19

3.3 Reconstruction ......................................................................................................................... 22

3.4 The Chaîne Opératoire of Pottery Production .......................................................................... 22

4. Results of the Analytical Methods ................................................................................................. 24

4.1 Clay and Tempering ................................................................................................................. 26

4.2 Forming Methods ..................................................................................................................... 29

5. Discussions..................................................................................................................................... 32

5.1 Clay and Tempering ................................................................................................................. 32

5.2 Forming Methods ..................................................................................................................... 36

5.3 Spread of Hellum Ware ............................................................................................................ 41

5.4 The Chaîne Opératoire ............................................................................................................. 42

5.5 Future Research........................................................................................................................ 44


iv

6. Conclusion ..................................................................................................................................... 46

References .......................................................................................................................................... 48

Appendix I: Ceramic Descriptions ..................................................................................................... 53

Journal Number 1399 ..................................................................................................................... 54

Journal Number 4158 ..................................................................................................................... 75

Appendix II: X-Radiography ............................................................................................................. 77

Appenix III: Ceramic Thin Sections .................................................................................................. 85

Fabric Descriptions of the Hellum Ceramics ................................................................................. 86

Fabric Description of Two Rims from Aalborg ............................................................................. 88

Fabric Descriptions of Clay Samples ............................................................................................. 90

Cover Page: Sherd X294 seen in visual

examination, x-ray, and thin section. Photo

after author.


v

Table of Figures and Tables Figure 1 ................................................................................................................................................ 2

Figure 2 ................................................................................................................................................ 5

Figure 3 ................................................................................................................................................ 7

Figure 4 ................................................................................................................................................ 8

Figure 5 ................................................................................................................................................ 9

Figure 6 .............................................................................................................................................. 10

Figure 7 .............................................................................................................................................. 11

Figure 8 .............................................................................................................................................. 12

Figure 9 .............................................................................................................................................. 14

Figure 10 ............................................................................................................................................ 15

Figure 11 ............................................................................................................................................ 18

Figure 12 ............................................................................................................................................ 18

Figure 13 ............................................................................................................................................ 19

Figure 14 ............................................................................................................................................ 21

Figure 15 ............................................................................................................................................ 23

Figure 16 ............................................................................................................................................ 25

Figure 17 ............................................................................................................................................ 26

Figure 18 ............................................................................................................................................ 27

Figure 19 ............................................................................................................................................ 28

Figure 20 ............................................................................................................................................ 29

Figure 21 ............................................................................................................................................ 29

Figure 22 ............................................................................................................................................ 31

Figure 23 ............................................................................................................................................ 32

Figure 24 ............................................................................................................................................ 33

Figure 25 ............................................................................................................................................ 35

Figure 26 ............................................................................................................................................ 36

Figure 27 ............................................................................................................................................ 37

Figure 28 ............................................................................................................................................ 38

Figure 29 ............................................................................................................................................ 39

Figure 30 ............................................................................................................................................ 40

Figure 31 ............................................................................................................................................ 41


vi

Figure 32 ............................................................................................................................................ 42

Figure 33 ............................................................................................................................................ 47

Table 01……………………………………………………………………………………………..17


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1. Introduction Within the area of Danish ceramic research, the methods used have seen little advancement since

the 1990’s. The latest book on Danish pottery was published by Jette Linaa in 2006, and focused

mainly on the social aspects of late medieval pottery. The last section of the book deals with the rim

typologies of different ceramic types, all of which are an average of a larger group of rims. The use

of typologies is useful in the sense that, for local pottery, they are easily used for comparison

between sites; but it should be said that Linaa’s work heavily resembles what has been done before

in Danish ceramic studies. It is not until recently, at the Baltic and North Atlantic Pottery Research

Group conference, in Stockholm, April 2016, that a discussion was opened on the use of Inductively

Coupled Plasma Spectrometry (ICP) analysis with a view to determining the grouping of certain

ceramics as well as the dating of these ceramics. However, this is a recent result and research from

before this conference has showed a lack of scientific focus on ceramic research despite its

usefulness being shown at least twice in differentiating between local and imported wares

(Christensen, et al., 1994; Rasmussen & Hjermind, 2005).

To address this lack of archaeometric research, i.e. the study of archaeological objects through

scientific methods, the aim of this dissertation will be to study how the use of archaeometric

methods can help expand the knowledge of pottery production and the processes involved herein.

Through the use of visual examination, x-radiography, and thin-section petrography of ceramic

sherds from the Hellum kiln, it is the author’s belief that there is a greater possibility for expanding

the chaîne opératoire of the products produced at Hellum in the 12th century. Apart from just

studying the ceramics, the dissertation will also focus on the geology of the area surrounding

Hellum in hopes of finding the clays the potter used for his ceramics.

Following this introduction, the dissertation will focus on the background for the study, wherein the

research history of Hellum, the theoretical basis, and the methods of the dissertation are covered in

greater detail. This will be followed by a short presentation of the results of the original study as

well as the author’s own results from the study of the sherds from Hellum. Finally, the discussion

will consider the implications of the new results against the original results, relating it to other

ethnographic research, as well as a final discussion on what these results may mean for the future of

ceramic research in Denmark, and what considerations need to be made. For a full overview of the

sherds and the methods used to study them see Appendix I-III.


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Figure 1 A map of Denmark and the kilns and wasters that have been found as of 2001. The kilns are represented by the

rectangular blocks while the wasters are represented by the stars. Photo after (Kock, 2004) the red, orange, and

purple blocks show the different kilns mentioned in the text.


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2. Background, Theories and Methods In the period 1983 to 1984, three kilns were found in Denmark, more specifically in Hellum,

Barmer, and Kragelund, and it was suggested that a larger project was undertaken to study these

kilns (Fig 1 – marked with red) (Kock 2001a: p. 7). Previously only two kilns had been found, the

first being the kiln of Farum Lillevang, found in 1955 (Fig 1 - marked with purple), and the second

being the Faurholm kiln found in 1975 (Fig 1 - marked with orange). Because of the sudden find of

these three kilns in such a short time span, it was decided that a larger project needed to be

undertaken with the main focus being on these kilns, their products, and a reconstruction of all three

kilns (Kockb 2001: p. 16). Apart from the Hellum kiln, which dates from the 12th century, all of the

ceramics are of a late medieval date ranging from the 13th to the 14th centuries (Jessen, 2001, p. 119;

Kock, 2001e, p. 111). Kock states that the discovery of these kilns. “… have helped increase our

understanding of a craft with strong traditional ties, which saw a large technological evolution in the

early Middle-Ages, and remained technologically static up until the first half of the 20th century.”

(Kock 2001: p. 15). Sadly, while the work was instrumental in starting the research of medieval

kilns as well as giving an overall plan of how the pottery traditions in Denmark changed, little

research has been carried out on these kilns since the publication of Hikuin 28 in 2001.

In Denmark, ceramic research can be divided into three main research tradition, which are

defined by Marianne Iversen as: “… the art historical tradition, the normative tradition, and the

contextual tradition…” (Iversen, 2001, p. 15), Iversen goes on to explain that each group sums up

the use of the pottery for each tradition.1 The interesting aspect here is that the description has not

moved beyond the basic study of the sherds as a finished product. The latest example of this can be

seen in Jette Linaa’s Keramik, Kultur og Kontakter 1350 – 1650, which was published in 2006,

where the ultimate result was a rim typology based on the average range of rims for each of the

types. When studying pottery this method is limited because the full scope of production is never

considered; thereby losing the interrelation existing between the potter and the raw materials (As,

1984, p. 138). Even with the increased use of Inductively Coupled Plasma Spectrometry (ICP)

analysis on Scandinavian ceramics, as seen at the first Baltic and North Atlantic Pottery Research

Group conference in Stockholm this year, the end result of said analysis was still a typological

grouping of certain ceramics. Jesper Langkilde, archaeologist at Roskilde Museum and PhD student

1 Translated from: “… den kunshitoriske tradition, den normative tradition, den kontekstuelle tradition…”


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at Copenhagen University, was the main presenter of this method, but he still used it on known

groups with the aim to push back the dating of glazed ceramics (Baltic and North Atlantic Pottery

Research Group, 2016).

Apart from the lack of evolution in Denmark, as far as standard ceramic research goes, there has

also been a severe lack of petrographic research done in Denmark on known Danish ceramics. The

last time it was done in Denmark was as part of the publication in Hikuin 28, where Anders Lindahl

studied the ceramics from Barmer, Hellum, and Kragelund petrographically, but only did clay

sourcing for the kiln at Kragelund though he never clearly shows the results of this clay sourcing

(2001). Apart from this, Alan Vince did petrography on what was believed to be imported materials

in 1994 and 2005, finding that some of these materials were in fact produced locally in Denmark

(Christen et. Al, 1994; Rasmussen & Hjermind, 2005). In England however, petrography has been

used to a higher degree, most recently by Dr. Gareth Perry in his study of the Torksey ceramic

industry, and the chaîne opératoire in the production of ceramics at this site. The aim of this project

was to study not only the chaîne opératoire of the Torksey pottery industry, which had only been

done loosely up to this point, and, when done, it was not done using archaeometric methods (Perry,

2016, p. 74). This research did also place the pottery of Torksey within a wider context of

production, studying the clay sources for the kiln and ceramics, the firing temperature of the

ceramics, and the production of the ceramics themselves (Perry, 2016, p. 72). Part of Dr. Perry’s

research also demonstrated the ability to study the spread of an industry through overall

characteristics of the pottery (2016).


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2.1 Theories and Methods Much of the basis for this dissertation is focused on the idea that the materialistic properties of the

object studied are more interesting than the dateable aspects of the product and the product itself .

Björn Nilsson presented this idea in an article from 2007, in which he states that “…field

archaeology has to shift focus: from the artefactual-chronological to the more structural-material.”

(Nilsson, 2007, pp. 29-30). Focusing on the materialistic properties of the finished products, allows

the archaeologist to study the interrelated aspects of the potter, the materials, and the actions taken

during production.

The best and clearest

way to study this range

of production is through

the use of chaîne

opératoire. This allows

the archaeologist to pull

the object into smaller

parts of a whole,

studying every step from

the gathering of

resources to the use,

reparation, and

discarding of said objects

(Fig 2). Within each

step, the artisan takes

actions that affect other steps in the production whether it be to temper the ceramics or dig clay with

natural inclusions so as to throw the pots more readily. While technically applicable to many forms

of archaeological materials, chaîne opératoire has been mainly used with lithic production, as the

end results can be found archaeologically, demonstrating “… the end result of a complex life

history.” (Andrefsky, 1998, p. 38). With this in mind, a short summary of chaîne opératoire and its

use in this dissertation will be given, before moving on to the methodology.

Figure 2

An example of Chaîne Opératoire looking at the production of flint tools. The graph

studies the entire lifespan from original production to repair into another tool.

Photo after Eriksen, 2000, p. 83.


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2.1.1 Chaîne opératoire Chaîne opératoire was originally proposed as a theory by André Leroi-Gourhan, being seen by

some as a reaction to the classical typologies of the early 20th century (Eriksen, 2000, p. 76; Bille &

Sørensen, 2012, p. 52). The use of this theory allowed archaeologists to not only to break down

typologies, but also classify artefacts while still considering the artefacts’ “… convergent functional

constraints and their divergent cultural variations…” (Trigger, 2006, p. 464). It has been suggested

that the application of this method could be used to study cultural transformations of the objects

from the acquisition of the raw materials, to the tools used, and the discarding of the archaeological

objects (Dobres, 2010, p. 106). However, Walls (2016, p. 22) does describe that there does not have

to be a cultural influence on each step, and that the cultural aspects are often unclear and “… are all

historically situated conventions…” (Walls, 2016, p. 22). Instead, Walls suggest that the process of

construction is a didactic process taking both materialistic aspects and the environment the objects

are situated within into account during the production (Walls, 2016, p. 29). Because of this, and the

fact that chaîne opératoire only stops with the object being discarded, the objects need to be studied

through “A wide range of analytical techniques… to attain a comprehensive reconstruction of the

operational sequence…” (Martinón-Torres, 2002, p. 33).

For the study of Hellum, this meant that a wide range of methods and finds had to be employed

to fully study the chaîne opératoire of the ceramic production of Hellum. While this will be covered

in the next chapter, it is worth noting that two of the ceramics were not from the kiln site, but were

from Aalborg and were believed to have been produced in Hellum. The aim of studying these

sherds would be to study the discarding of possible Hellum ceramics far from the kiln site. It is also

more likely that the pots from Hellum show more about what was available to the potters than

something that is culturally significant (Andrefsky, 1998, p. 37). In the case of the Hellum kiln,

where the products are not decorated, and are most likely cooking pots with little social

significance, a purely technological approach will be taken. The next section will focus on the

methods used to study these technological aspects of the pottery production, as well as how one

method supports the next.


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2.2 Methodology To achieve the best result for this dissertation, it was important that the different methods used

helped each other as much as possible so that one method would supplement the next. To this end, it

was decided that a combination of visual examination, x-radiography, and thin-section petrography

would be the best approach for the study of the sherds. With the exception of visual examination, all

of the methods rely on the idea of preferred orientation. This idea was originally presented by Owen

Rye, an Australian ceramicist, in a paper from

1977 where he states that: “… different forming

techniques involve different and characteristic

applications of pressure to plastic clay, and that

inclusions in the clay take up preferred

orientations which are characteristic of the

forming operations.” (Rye, 1977, p. 208). The

affected clay particles are particularly the voids

and elongated inclusions that align themselves

accordingly (Fig 3) and can be studied through

x-radiography and thin-section, showing

slightly different aspects of the sherd and in

different levels of detail.

2.2.1 Visual Examination The first part of the study will focus mainly on a

purely visual description of the sherds from

Hellum. The main goal for this was to first get a

better understanding of the sherds from Hellum,

and second to select a few sherds from the

group for x-radiography. Apart from this, it also

helped in choosing where to lay the cut on the

sherds that would not be x-rayed. The

descriptions themselves were based on a system

laid down by Hartwig Lüdtke (2001), where the sherds are systematically described through a set

various of factors; though it should be noted that some of the descriptive terms, such as the use of a

munsell chart for determining color, was omitted on the basis that it would only serve to confuse

Figure 3

A diagram showing the different aspects of production

and how the orientation of the microstructures of the

clay is affected through different production methods. It

is understood the cross-section refers to a vertical cut in

the ceramics. Photo after (Berg, 2008, p. 1178)


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rather than aid in the understanding of the ceramics. The full results of the visual examination can

be seen in Appendix I.

2.2.2 X-Radiography

Due to the fact that there was a need

for a thorough examination of the

sherds prior to the sherds being thin-

sectioned, as it would ensure that

when the cuts were made for the thin-

sections they would be correct the first

time, an analytical method that did not

facilitate a partial destruction of the

sherds was needed. To this end, x-

radiography was used for an

examination of the sherds as it has

been used in other ceramic research to

study the production of the sherds. X-

rays are produced through a longer

process of heating a filament, which

releases electrons that are focused

with an electromagnet and are directed

towards a target, which then releases

the x-rays that hit the object and

imprint on a radiographic film behind

the object itself (Fig 4) (Carr & Riddick, 1990, pp. 36-37).

This method was originally used on ceramic material by Owen Rye, an Australian archaeologist

and ceramic specialist, in 1977 during a study of the production of Papuan pottery (Rye, 1977, p.

205). The reason he used this theory to study the production was that “… some 90% excavated

pottery allows no definite statements about the forming technique, even with the aid of data gained

by ethnographic studies of traditional potters.” (Rye, 1977, p. 205). Through the use of this method,

Rye was able to not just study the forming techniques but also “… to study variations in temper

Figure 4

A diagram showing the steps involved in X-radiography. It should

be noted that the x-rays for this dissertation were not taken with a

stationary machine, as seen here, but the principal is the same.

Photo after (Carr & Riddick, 1990, p. 37)


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quantity and particle size range, and to

select representative or unusual specimens for

thin section studies…” (Rye, 1977, p. 208).

The x-radiography was used in much the

same way for this dissertation, though

representative pieces were chosen for study

rather than unusual ones, the pots all being of

the same type. Despite Anna Shephard, an

American ceramic specialist, suggesting that

X-rays could help study “… relations

between orientation of particles and direction

of forces applied in building…” (Shephard,

1954, p. 183), it was not until Rye used x-

radiography that if was demonstrated how it

could be used to study a large number of

sherds with little cost or preparation time

needed (Carr, 1990, p. 205; Braun, 1982, p.

185; Rye, 1977, p. 205). Further use of this

method by Christopher Carr and Riddick also

showed how it could be used to study and

distinguish individual vessels as well as

sorting large amounts of sherds (Carr &

Riddick, 1990, p. 104). Through their

research, they determined that it could be

used “… in the descriptive stages of ceramic archaeological research.” (Carr & Riddick, 1990, p.

114). . After a period of little research using x-radiography, Ina Berg has used x-radiography to

study the differences in wheel-throwing and wheel-finishing on pottery, attributing the rise of its

use to the “… appreciation of the power of imaging software programmes…” (Berg, 2008, p. 1177).

Her use of the method has not only enabled the study of primary, but also secondary forming

techniques during pottery production, as well as showing that archaeologists are not always correct

in their determination of these forming methods, and enabling the study of chaîne opératoire on

vessels (Berg, 2008, 2009, 2011).

Figure 5

An example of the reconstruction of a single sherd being

reconstructed from a series of smaller x-rays. This was

done to ensure that no area went without being x-rayed.

Photo after author.


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One of the largest challenges in the earliest parts of x-radiography was the need for using film

for the x-rays, as mentioned by David Braun (1982). Using films requires grouping sherds by

thickness, as the exposure would be roughly the same for these sherds. Apart from the need to use

film to study the sherds one of the other problems that faced x-radiography are the factors of a low

contrast and mediocre resolutions, though Carr says this “… can be largely overcome by using

certain industrial and never medical radiographic methods and materials…” (Carr, 1990, p. 14).

While the early use of x-

radiography faced the above

problems, the use of the

method for this dissertation

has not relied on the use of

films. Instead, in the same

vein as Ina Berg, it was

possible to get digital x-rays

through the use of a Nomad

Pro X-ray “gun” and a Shick

CDR Elite Size 2 x-ray

detector, which could be

attached to a computer and

show the digital images using a software called Dicom. The x-rays were taken in the basement of

the Northgate Department of the University of Sheffield by Dr. Gareth Perry, with the Shick CDR

remaining stationary and the sherd being moved in accordance with where the x-rays were needed.

The author was present while the x-rays were taken, but he was not certified to use the x-ray

equipment. Because the X-ray equipment used is a type also used by dentists, it could only take x-

rays of relatively small areas, so some of the larger sherds such as X294 needed 23 pictures to be

composited to a single picture while smaller sherds such as X485 only needed eight pictures. Each

x-ray was only a fragment of the whole (Fig 6), and, therefore, had to be merged in Photoshop with

one sherd having its pictures printed at put together to check whether all the photos were taken (Fig

5). Part of this did involve editing the contrast slightly in each picture as some of the x-rays came

out darker than the rest despite a constant set exposure of 35 for each of the sherds. This exposure

Figure 6

An example of one picture taken during the x-ray before it was merged.

Photo after author.


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was reached based on several rounds of testing x-rays being carried out on the sherds that ranged in

thickness from 0.4 to 1.0 cm. It was possible to do this due to the x-rays being taken digitally,

allowing quicker changes as needed.

2.2.3 Thin-Section Petrography

Petrography is a technique typically used

by earth sciences for study the mineralogy

of rocks and sediments, which has been

adapted for use in archaeology due to the

similarities between ceramics, rocks, and

sediments (Peacock, 1970, p. 379; Orton &

Hughes, 2013, p. 162). Using this method,

the ceramics are cut and ground until they

reach a thickness of 0.03 mm, allowing

light to pass through the minerals in the

sherds, which can be observed in a

petrological microscope (Peacock, 1970, p.

379). It was developed by Henry Clifton

Sorby, a British scientist, who originally

used it on ceramic building materials from

the Roman and Medieval periods (Quinn,

2013, p. 10). In England, petrography has

been used on various types of ceramics

ranging from Iron Age to Late Medieval

pottery to study industries and has assisted

in disproving the theory held by archaeologists that coarse ware ceramics were not traded over long

distances (Quinn, 2013, p. 12).

The process involved in making the thin-section is relatively simple, requiring a few rounds of

cutting and polishing before the slide is ready. The first part consists of cutting each sherd on a tile

saw, in either a horizontal (Top down), vertical (side), or tangential (frontal) view depending in

relation to the sherd. The best way to ensure the correctness of these cuts is to determine sherd

Figure 7

Sherd X485, which shows marks as the result of production,

possibly the result of joining of the clays during the

production. Note the slight signs of wiping on the lower part

of the sherd, highlighted with the blue circle. Photo after

author.


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orientation through production marks, such as coils, wheel-throwing marks, or wiping marks (Fig

7). Following the cutting, the sherds were polished with 320 grit carborundum and then covered in

an epoxy resin. Following this, the resin is polished with 600 grit carborundum until the resin

appears cloudy on the sherd, similar carborundum is used for the slide onto which the sherd is

glued. The glued sherd is then cut again on another machine, a Hillquist saw with a blade and

grinding area. Finally, the slides are polished with a 600 grit carborundum again to ensure the

optimal thickness.

One of the biggest weaknesses that should be considered when using thin-section petrography is

that the method for producing the thin-sections varies heavily. For example, when producing thin-

sections for low and high fired ceramics, more care should be taken with the low fired ceramics, as

they are more friable than their high fired counterparts. This in turn adds extra steps to the

production of the thin-sections as well as the need for extra care during the hand polishing and

polishing on a machine. One way to solve the friability of low-fired ceramics is to resin the

ceramics between the original

cutting and polishing of the

ceramics, as well as using 600

grit carborundum, which will

prevent the sherds from falling

apart (Nicholson, 1989). In

spite of these difficulties and

extra steps, once the thin-

sections are finished, the

information they offer

microscopically is more useful

than what the visual

examination of sherds would be

able to offer. Through the use

of petrography, sherds from

different sites can be compared

and grouped based on the mineralogical and production characteristics of the sherds rather than just

what is observed in hand specimen. If one finds a kiln site, and knows of the local clays, it is

Figure 8

A map of the areas covered by GEUS in 1989, marked in grey, which were

then used as a basis for the 1:200,000 maps. The red dot marks the rough

position of Hellum on the map. Photo after (Pedersen, et al., 2011, p. 2), the

red dot is inserted by the author.


Page | 13

possible to compare the mineralogy of the clays to those of the sherds (Perry, 2016, p. 87; Quinn,

2013, p. 154). This is assuming that there is a difference in the clays available to the potters or that

the clays are not levigated, i.e. cleaned of inclusions (Quinn, 2013, p. 156).


Page | 14

Figure 9

A map of the geology surrounding the production area of Hellum with a red dot marking the Hellum kiln and a blue dot marking the sampling area in Siem Skov. The legend to

the right reads from the top down: Aeolian Sand, Freshwater formations, Marsh, Marine Sand and clay, beach ridges, Moraine sand and gravel, Till/Boulder clay, Meltwater

sand and gravel, Meltwater formations, Extra marginal deposits, Ancient sea deposits, pre-Quaternary formations, lakes, and fill, harbors, dams, and dikes. Photo after (GEUS,

2011). Dots added by author.


Page | 15

2.2.4 Acquisition of

Material As mentioned in the last

section concerning the use of

petrography, one can

potentially use the local clays

to determine what materials

were available to the potter.

This could in term help

determine the range of clays

as well as what the local

geology looked like. The clays

selected for the sampling was

done so on the basis of a

geological map produced by

GEUS in 1:200,000 scale (Fig

9). The map was produced in

1989 as a summary of a

number of 1:25,000 scale

geological maps, which

covered roughly 77% of

Denmark in 1989 (Fig 8)

(Pedersen, et al., 2011, p. 2).

It is recognized that the maps

may have some issues

concerning accuracy, the

authors make mention of this and state that “These issues are, as and when possible, righted and

will be of not major importance in a scale of 1:200,000, at which the map is intended to be used.”

(Pedersen, et al., 2011, p. 4).2

2 Translated: “Disse fejl er i videst muligt omfang søgt rettet og vil typisk være uden betydning i det målestoksforhold

1:200.000, som kortet er beregnet til at blive anvendt i.”

Figure 10

The boxes of ceramics made available to the author during the study of the

ceramics. Photo after author.


Page | 16

For the clay sampling, the inaccuracy of the map meant that the geological sampling did not

always manage to dig up clays despite digging almost a meter down in some areas with a hand

auger. In some cases, the land owners made suggestions to where clay may have been present, but

even with help from landowners it was not always possible to find clay (see chapter 4.1 for more on

this subject). In one case of clay sampling on the Lindenborg Royal Hunting Grounds (Fig 8), the

administrator of the estate, Henrik Thorlacius-Ussing pointed towards a known brick production

site that had clay in the area, which did not appear on the map provided by GEUS. The clay

samples, that were selected for thin-sectioning, were fired in an oxidized atmosphere in a kiln at the

University of Sheffield at a max temperature of 850 °C with the kiln heating up at a rate of 200 °C

until it reached the desired temperature and held there for one hour.

The ceramics from Hellum were stored at Nordjyllands Historiske Museum, referred to hereafter

as NHM, after their original excavation in 1983. In total, six boxes (Fig 10) full of ceramics were

studied, and, from these boxes, 21 sherds were selected for thin-section petrography (Table 1). The

boxes contained mainly body sherds with a few shoulder sherds in some of the boxes. The sherds

selected from these boxes were picked based on the visible productions marks and colors of the

sherds as a result of firing.

To summarize the methods for this dissertation, an array of methods were used to study the

sherds from Hellum. Not all of the methods were used on all of the sherds studied in this

dissertation, for example while all sherds and clay sample were thin-sectioned, not all sherds were

subjected to x-radiography (See Table X for an overview of all the materials). Since all but two

sherds were from Hellum, it could be assumed that sherds with similar visible production marks

would exhibit the same results during the x-radiography. Inversely, the reason for all of the sherds

being thin-sectioned was to gain a wider idea of the mineralogy of the ceramics and having as much

data as possible to compare to the clay samples. While roughly 20 clay samples were taken, only

about half were examined in thin-section as the rest were either not able to be formed into brickets,

or were so friable that they could not be cut or polished properly for thin-section.


Page | 17

REF. NUMBER VISUAL EXAMINATION X-RADIOGRAPHY THIN-SECTION

1399X241 X X

1399X002 X X

1399X418 X X

1399X004 X X

1399X003 X X

1399X503 X X

1399X005 X X

1399X217 X X

1399X410 X X

1399X177 X X

1399X431 X X

1399X428 X X

1399X471 X X

1399X146 X X

1399X168 X X

1399X002 X X

1399X485 X X X

1399X142 X X X

1399X155 X X X

1399X336 X X X

1399X294 X X X

4185X216A X X X

4185X216B X X

CLAY SAMPLE I X

CLAY SAMPLE II X

CLAY SAMPLE III X

CLAY SAMPLE IV X

CLAY SAMPLE VII X

CLAY SAMPLE IX X

SIEM SKOV VI X

SIEM SKOV VII X

SIEM SKOV VIII X

SIEM SKOV X X

Table 1

An overview of all the sherds and clay samples studied during the dissertation. The sherds from Hellum are

marked with 1399, which is the journal number for the Hellum excavation. Meanwhile the sherds from

Aalborg are marked with 4185, which is the journal number from their excavation.


Page | 18

3. The Hellum

Industry The aim of this section is to give a

better understanding of the history

and development of the pottery

industry around Hellum as well as

cover the research that has already

been done on the ceramics. As

mentioned in the introduction, the

last publication on the industry is

from in 2001 as part of a larger

study of the Danish ceramic

industries.

3.1 Kiln and Ceramics The Hellum kiln was originally

discovered in January 1983

following “…preparation of the

soil for construction…”

(Springborg, 1983, p. 1).3 The

report is only eight pages long,

and lacks a detailed description of

the finds, with most of what was

found only being described in the context descriptions (Springborg, 1983, p. 6). Apart from the

ceramics, parts of the kiln cap were also found. The kiln site was characterized by a large amount of

charred material and burnt ceramics (Springborg, 1983, p. 6). Springborg determined that the kiln

was similar to other kilns found in England, with a separate area for the fuel and stacking the

pottery, with the pottery being stacked on a wheel-shaped platform, which is reminiscent of the type

1b kilns seen throughout the eastern part of England and described by Musty (Fig 11) (Musty, 1974,

p. 44; Springborg, 1983, p. 7).

3 Translated from: ”..forberedelse af jorden til byggeri...”

Figure 11

A diagram of the kiln excavated at Hellum. At the center of the kiln is

placed a stone, which supports the kiln platform. Height measurements

erased by author, photo after Kock 2001.

Figure 12

An example of some of the more complete vessels from Hellum. Photo

after (Kock, 2001d)


Page | 19

Jan Kock did study the ceramics after the excavation, determining there to be sherds from

roughly 70 vessels inside the remnants of the kiln and 30 in the area in front of the flue (Kock,

2001d, p. 89). Through his study of the ceramics he determined that the dominant pottery type was

the globular cooking pot (Fig 12), with a rim diameter ranging in size from 13 cm to 25 cm. From

his descriptions it can be said that the ceramics are typical of the early 12th century, containing

nothing in ways of decorations, handles, or feet typical of pots from the later periods in Denmark

(Kock, 2001d, pp. 89-95). The pots were produced through a series of methods, being “… pulled,

beaten, and coiled.” (Kock, 2001d, p. 95).4 He also determined the clay for the ceramics as being

tempered with “… granite that was made brittle by fire and then crushed.” (Ibid: p. 95).5 Kock also

describes the walls of the kiln as being “...heavily tempered to the touch... [the clay] had a high

level of sand, which was necessary to

ensure adequate ability of the kiln to

sustain the effects of the heat from

the firings.” (Kock, 2001c, p. 19).6

3.2 Thin Section As mentioned in the section on the

previous research, Anders Lindahl’s

role in the overall project was to

study the kiln products from Hellum,

Barmer, and Kragelund in order to

determine the clay recipes so that “…

the pots that would be fired in the

kilns would not just have the same

form, but also be made of material as

close to their medieval counterparts as possible.” (Lindahl, 2001, p. 281).7 One of his questions was

also to study “To what degree the natural clay is discernable from the clay in the sherds.” (Ibid),

4 Translated from: “... trukket, banket og pølset op.” 5 Translated from: “… ildskørnet og knust granit.” 6 Translated from: “… var Ganske mageret at føle på… [leret] at det havde en højt indhold af sand, hvilket har

været nødvendigt for at give en tilstrækkelig holdbarhed over for varmepåvirkningen.” 7 Translated from: ”... de kärl som skulle brännas i ugnarna inte bara skulle ha samme form som originalen utan även

ha en sammansättning av råmaterial som skulle vara så lik e medeltida kärlen som möjligt.”

HELLUM

I II III

CLAY

ROUGHNESS M F F

FINENESS DEGREE % 84 95 95

FEOHO - * *

PRESENCE OF FINE

CLAY EO * *

INCLUSIONS

TYPE K K K

PERCENTAGE 17 16 16

MAX INC SIZE 1,10 1,20 1,20

MIN INC SIZE 0,14 0,11 0,10

PRODUCTION METHOD T T T

FIRING METHOD R/O R R/O

Figure 13

The results of the petrology done by Lindahl. The key to the result are

as follows:

M = Median, F = Fine, * = Median, - = Little, K = Crushed Rock, t

= Pinched, R = Reduced, O = Oxidized.

Chart after Lindahl 2001: 287.


Page | 20

though this question was only answered for the Kragelund kiln.8 Lindahl determined that the temper

used for the sherds was granitic in nature, consisting of quartz, feldspars, micas, and ore materials

(Fig 13 and Fig 14) (Lindahl, 2001, p. 290). He also mentions that the vessels were “… pinched

from a lump of clay.” (Lindahl, 2001, p. 289).9

8 Translated from: “I vilken omfattning skiljer sig den föreslagna råleran från leran I keramikskärvorna.” 9 Translated from: “… tummats up ur en lerklump.”


Page | 21

(A) (B)

(C)

Figure 14

A picture showing the three thin sections made by Anders Lindahl as part of his

publication in 2001. The photos are meant to highlight the different parts of

production visible in the sherds. Photos after author, slides are courtesy of Anders

Lindahl


Page | 22

3.3 Reconstruction As part of the 1983 excavation, Annette Bibby and Inge Sell were brought in to discuss the kiln find

due to their expertise in the reconstruction of archaeological ceramics (Kock, 2001c, p. 18). In

terms of the whole project surrounding the publication of Hikuin 28, their expertise in

reconstruction was used to reproduce the ceramics and the kiln from Hellum. As part of their

attempts at reconstruction they also examined the vessels determining that they were produced

through a technique known as paddle and anvil since “None of the sherds have signs of wheel-

throwing nor do they contain traces of coiling. Therefore, one has to assume that they were pulled

and paddled to shape” (Bibby & Sell, 2001, p. 302).10 As well as the formation of the vessel through

paddle and anvil, they also mention that the clay was tempered with the aforementioned granite

(Ibid). One could argue that the reason for the paddle and anvil production of the vessels is due to

their globular shape and paddle and anvil lends itself better for a sitting production, which is to say

a production where the potter manufactures the ceramics while sitting.

3.4 The Chaîne Opératoire of Pottery Production If one looks at the different production methods suggested by the above mentioned authors, one can

begin to outline a chaîne opératoire for the production of the wares from Hellum. The goal of this

part of the dissertation is to briefly summarize the different studies of the Hellum kiln and its

products, focusing specifically on the production aspects of the quickly sum up the different studies

that were done on the Hellum ceramics after its excavation.

While the different articles studied completely different aspects of the pottery production there

are still some major steps that have been discussed by all three of the researchers who have studied

the ceramics. One such area of agreement concerns the addition of temper to the clay before the

vessels were formed by the potter (Bibby & Sell, 2001, p. 302; Kock, 2001b, p. 95; Lindahl, 2001,

p. 290). While there is some agreement on the degree to which the clay has been tempered, there are

different accounts offered of the perceived methods of forming applied to the vessels. Jan Kock

suggested that there were three methods of production, including coiling, paddling, and pinching

(Kock 2001: p. 95), meanwhile Bibby & Sell (2001) argued for that there was a distinct lack of

coiling visible in the vessel and instead argued for the use of paddle and anvil as it would explain

how the potters made the globular cooking pots. Lindahl (2001) does discuss the use of coiling in

10 Translated from: “Ingen af skårene har drejeriller og der er heller ingen spor af egentligt oppølsning. Man må derfor

gå ud fra, at karrene har været trukket og banket op.”


Page | 23

the production of the Hellum sherds, but mentions pinching in all of his descriptions. The main

differences between each of the forming methods is, as mentioned in the section on methodologies,

the pressure that they put on the clay, thereby changing the orientation of the particles in the clay.

For coiling, the pressure is two-fold, from the forming of the coils as well as the joining of the coils

(Fig 25). For paddle and anvil, the pressures are from both sides of the vessel, and the beating

motion aligns the clay particles so that they run parallel with the wall (Fig 25). Pinching and pulling

can be said to essentially be the same methods of production involving the same motions for

forming, except that pinching results in a random preferred orientation while pulling results in a

perfect preferred orientation (Fig 25).

In terms of

chaîne opératoire,

the implication is

that the Hellum

potter would dig up

the local clays of

the area and temper

the clay with

granite for the

pottery and sand for

the walls of the

kiln. After the clay

mixing, the potter

would form the

vessels through

either coiling,

pinching, or paddle

and anvil, where

the strongest

argument is that of

Bibby & Sell seeing as it would be possible to form the vessel in one sitting and takes the vessel

shape into account. After the forming of the vessel they would have been dried, fired, and left to

Figure 15

A diagram giving an overview of the different step of the chaîne opératoire as

presented by the different authors who originally studied the Hellum Kiln.

Diagram after Author.


Page | 24

cool down before they could be used (Fig 15). Having quickly summed up the chaîne opératoire of

the Hellum ceramics, as proposed by other authors, the next section will focus on the results of the

analytical methods undertaken for this dissertation.

4. Results of the Analytical Methods Having covered the previous research done at Hellum, the focus will turn to the author’s own

results after having studied the Hellum ceramics using the different methods described in the

previous chapter. The first area of focus will be on the clay samples taken in the area, with special

focus on the thin-sectioning of the samples. Following this, there will be a presentation of the

results from the thin-section petrography on the sherds, taking into account the inclusions and

forming methods seen in the sherds. It should be noted that only the basic results will be covered

here, instead leaving the discussion of these results against the results of the original research from

Hikuin 28 for the next chapter.


Page | 25

Figure 16

A geological map of the studied area. The map is in 1:200,000 scale and sadly not very accurate. The red shows the first round of clay sampling

while the blue shows the second round of clay sampling with the Hellum Kiln marked by the white arrow.. The kiln is located in the arindicates the

original position of the kiln while the brown areas indicate moraine clay. The points were inserted by the author, with the base map courtesy of Aerodata

International Surveys through Google Earth. The same geological map as seen in chapter 2.2.3 from GEUS after GEUS, 2011.


Page | 26

4.1 Clay and Tempering To answer the question of whether or not the inclusions seen in the ceramics were added as temper

or occurred naturally in the clay, geological samples of the area surrounding Hellum were taken

over a course of three days, with permission obtained from the landowners (Fig 16). The idea with

sampling over a wide area was of course to establish the clay source used for the ceramic

production, but also to gain an understanding of the local geology, as it could be further indication

of whether or not the inclusions are natural. The first samples, which were taken in Asp, to the west

of Hellum, near the kiln site, south of the site, and in Siem, which was suggested as a possible clay

source in the original study (Kock, 2001c). However, first samples turned up very little, the clays in

thin-sections were mostly sandy, containing only singular inclusions close to what was seen in the

sherds. However, these clays may represent the materials used for the kilns, which are

“…dominated by fine sand, and have a large concentration of median to rough silt. Stone and gravel

inclusions are low in concentrations.” 11 (Hansen & Sørensen 2001: 245). However, the original

analysis of the kiln walls is, as of now, unavailable making this hypothesis pure conjecture. The

second round of clay sampling was done in Siem Forest to the South West of Hellum (Fig 17). The

main reason for

sampling in this

area was based on

a publication of

the local history of

Hellum describing

how the potters

produced their

pots. In the book it

is described how

the “The clay was

acquired in Siem

Skov.” (Moestrup

& Moestrup, 2007,

p. 119), this is because the clay in the area surrounding Hellum was not good for throwing pots, and

11 “… domineret af finsand og har ret stort indhold af mellemsand og grovsilt. Sten- og grusindholdet er meget

lille.”

Figure 17

A closer view of the second round of clay sampling in the area of Siem Skov. The reason for

some of the samples like 1 and 2 as well as 5 and 6 being placed so closely together was

due to the forest interfering with the GPS. The points were inserted by the author, with the

base map courtesy of Aerodata International Surveys through Google Earth. The same

geological map as seen in chapter in chapter 2.2.3 from GEUS after GEUS, 2011.


Page | 27

was only used to wattle and daub the houses (Moestrup & Moestrup, 2007, p. 119). The biggest

difference between the clay samples from this area and the clay samples from Siem Forest is the

amount of clay in each of the samples.

In thin-section, both samples were found to contain the same types of inclusions, which were

quartz, microcline, and

plagioclase, with some of the

quartz having perthitic or

myrmekitic textures. Inclusions of

pyroxenes, sillimanite, and biotite

as well. As these types of

inclusions were found in both

rounds of clay sampling indicating

that the local geology was quite

similar. The biggest difference

between the two rounds of clay

sampling was that the second

round contained more clay matrix,

which explained why it was easier

to form during the production of

brickets (Fig 18). When the

ceramics where thin-sectioned

similar types of inclusions were

seen in the sherds, being similar in

not only type but also general size

and angularity (see chapter 5.1 for

the discussion of these result and

Fig 19). The biggest difference

between the sherds and the clay samples was that only a few areas of the clay samples had the same

appearance as the sherds from the Hellum kiln, as well as a lack of biotite in the thin-sections of the

clay samples. However, as the site of the second clay sampling was a brick works, now out of use,

which may have mixed several layers of clay hence the higher sphericity of some areas of the clay

Figure 18

Clay Sample I (top) and Siem Skov VIII (Bottom) in thin-section. Photos

after author


Page | 28

samples. Due to the nature of the concentration of certain inclusions, and the overall median

coarseness of the clay, it can be suggested that the inclusions are from the igneous rock known as

diorite and not as originally suggested, granite.

Figure 19 The thin-section for sherd X294, showing the biotite, sillimanite, perthitic quartz, as well

as quartz throughout the thin-section. Note how the elongated pieces follow the central

coil, while the biotite to the right runs parallel to the vessel wall. This is an indication that

the vessel is coiled with the outside being smoothed during forming.


Page | 29

4.2 Forming Methods To study the forming methods of the

sherds, two main methods were used,

petrography and X-ray radiography.

As mentioned earlier these two

methods can essentially study the same

aspects, but the field of view on the

sherds in question is a lot wider on the

x-ray radiography. As mentioned in

chapter 2.2 Methodology (see 2.2.2),

the sherds that were selected for x-

radiography, were selected based on

their visual characteristics, some of

which were believed to show multiple

production methods. The results of the

x-radiography showed that this was

indeed the case (Fig 21 and Fig 24 –

See Appendix II for the full results),

and that it most likely occurred at the

maximum vessel diameter (Fig 20),

with the clay being molded to this

point and coiled afterwards. As both of

these production methods leave

distinctive marks on the sherds, the

sherds that were not subjected to x-

radiography could then be grouped

based on similar visual characteristics.

When the sherds were thin-

sectioned, they were studied under a

microscope to determine whether the grouping of sherds that had been suggested during x-

radiography could also be proven using in thin-section petrography. The thin-sections showed that

this grouping was visible with sherds belonging to below the maximum vessel diameter showing

Figure 20

A reconstruction of a vessel from Hellum with the red line marking

the max diameter of the vessel. The rim drawing has been

duplicated by the author and the red line added. While a 10 cm

scale did accompany the drawing, the scale was offset at 3.4 cm:10

cm, therefore this drawing is only meant as being a representation

of the vessel, not to show the actual vessel itself. Photo after Kock

2001: p. 92.

Figure 21

A picture showing sherd X485 from Hellum which was also

found to have multiple steps of production visible on the

sherd. The yellow lines marks the areas above and below

where the max vessel diameter is believed to have occurred.


Page | 30

signs of molding while the sherds belonging above the maximum vessel diameter showed signs of

coiling. Here the preferred orientation of the elongated inclusions and voids was crucial for the

interpretation of these sherds, the inclusions in this group mainly consisting of biotite, sillimanite,

and the occasional elongated quartz inclusion. For sherds X485 and X294, the difference in

production could be seen through the orientation of the aforementioned inclusions, with the micas

above the line conforming with the coils, i.e. following the preferred orientation of the coils, while

the ones below the maximum vessel diameter ran parallel with the vessel walls (Fig 22 – for a full

description see Appendix III).


Page | 31

Figure 22

Sherd X485 in thin-section, which displayed

characteristics similar to that seen in the x-

radiography. Here the biotites were helpful to

determine what was above and below the

maximum vessel diameter (marked below in

red). The biotites indicating the preferred

orientation are marked with red boxes in the

lower picture. Photo after author.


Page | 32

5. Discussions The aim of this discussion is to consider the original interpretations of the ceramics from Hellum

and compare them to the interpretations of the author’s own study and use of analytical methods.

Part of the discussion will also be on how the different interpretations affect the chaîne opératoire

by either adding or removing steps. Apart from this, there will also be a short discussion of the

possibility of identifying the spread of the ceramics from this kiln to other sites.

5.1 Clay and Tempering

While the sherds did all contain similar types and sizes of inclusions, there were still some minor

difference, such as the ceramics containing more biotite than what was visible in the geological

thin-sections. However, this could be due to aforementioned mixing of the clays from the Siem

Skov area, being mixed with the other natural clays and the biotite just not appearing in the thin-

sections. Because of the samples showing the same mineralogical makeup, it does seem much more

likely that not only is the local geology roughly the same size and shape as the inclusions in the pot,

but also that the potters used local materials for the pots. More importantly the clays from Siem

Skov show the same behavior post firing as the sherds from the Hellum kiln do (Fig 25). By modern

roads this clay source is roughly 6.5 Km from the production site, within the 7 Km normally said to

be travelled by potters for their resources gathering (Arnold, et al., 1991, p. 85).

While Anders

Lindahl originally

suggested the clay to

have had, granite

added as a temper,

the results of the

thin-section point to

a more basic igneous

rock, namely diorite

(Fig 23). The sherds

and clay samples lack the dominance of coarseness that typically characterizes granite. As the

largest grains observed in the thin-sections are only 1.72 mm, they are not what is typically

Figure 23

A diagram showing the variants of igneous rocks, with the name in the chart below and

the rough mineralogy of the rocks in the graph. Photo after Cox, Price, & Harte, 1988, p.

163.


Page | 33

considered to be coarse-grained in igneous rocks that are normally larger than 5 mm (MacKenzie, et

al., 1982, p. 12).

When looking to the clays, as has been noted in chapter 4.1, there is a difference in the amount

of matrix for each clay source. This means that, while it does appear the potters in Hellum used the

local clay sources available, what

was available to the potters in

Hellum was unsuitable for producing

pottery. With the description of the

later pottery industry by Moestrup

and Moestrup, as well as what Jan

Kock said on the potters from the

17th century (Kock, 1975), it seems

likely that the local clays from

around and within Hellum were

perfect for kiln construction, but the

potters had to travel farther to find

clays that had the plasticity needed

to form them into functional pottery.

If this is the clay source for the

medieval Hellum ceramics, then it

means that the potters from the 19th

and early 20th centuries were using

the same clay as the medieval

potters. This would mean that the

potters only changed the vessels they

produced and the methods they used

to produce said vessels. With this in mind, it would be possible to get an idea of the spread of

Hellum ware from the production center to the rest of Denmark, especially since it is unique from

the other ceramics that were thin-sectioned for the original project surrounding the Hellum kiln.

Figure 24

Sherd X155 from the Hellum Kiln. The top picture has had its light

manipulated to show production marks that are visible on the inside

of the vessel while the outside which has been smoothed leaving no

distinct production marks. Photo after author.


Page | 34

In Dr. Perry’s article on Torksey ware, he was able to determine that, while potters had multiple

clay sources to choose from, that they still chose the Rhaetic clay sources furthest from the

production area. This was determined to be the result of the clay’s naturally sandy properties, which

made it easier to throw on a wheel with minimum need for processing after the clay was dug up

(Perry 2016: p. 86, 90). While the potters in Torksey had access to multiple clay sources, the

geological maps of the area surrounding Hellum only showed one clay type (Fig 16). From the clay

sampling, it was noted that the main difference between the samples from the area was not a

difference in inclusions, but instead a difference in how much clay was in the soil. The first round,

as noted in the previous chapter, had a large concentration of inclusions compared to the second

round of sampling. The result of this was that the brickets in the first round of sampling were tough

to form and fell apart easily while the brickets from the second round were easily formed into

squares and did not fall apart during their forming. In this case, one could use Wall’s argument of

this choice in chaîne opératoire not necessarily being a cultural one (Wall 2016: p. 22). Instead, it

follows the theoretical basis that Sillar and Tite put forward that the person in charge of the

production is influenced by both direct and indirect choices during the production of the item in

question (Sillar & Tite, 2000, p. 7).


Page | 35

(A) (B)

(C) (D)

Figure 25 A comparison of 3 sherds from Hellum X005 (A), X004 (B), X410 (C), and clay sample Siem Skov VIII (D). Note the clay pellets seen in the clay sample which is

recognizable in the other sherds as well. Also note that X410 (C) has a similar inclusion size as the clay sample. Photos after author.


Page | 36

5.2 Forming Methods

Having discussed the implication of the natural inclusions in the chaîne opératoire of the Hellum

ceramic production, this section will consider the forming processes of the Hellum ceramics,

discussing them against what is known from the archaeometric analysis of the sherds. Since the

author’s own analysis was limited to the study of the Hellum kilns, and there was a discrepancy

between those results

and the results achieved

in the original study, the

author’s results will be

compared to other

results from

ethnographic studies.

As mentioned in the

original results, there were several production methods suggested for the Hellum vessel, pinching,

paddle and anvil, and coiling. Based on the idea of preferred orientation presented by Owen Rye

(1977), the pressures exerted on these vessels would leave “relics” of the production in the matrix

of the vessel even if they were wiped away or hidden through other production methods (Fig 26 &

24). The results of the analytical methods will be covered in the same way that the sherds were

originally examined, starting with the x-radiography and then discussing the results of the thin-

sections. The main part of the x-radiography discussion will focus on the pinching and paddle and

anvil as it was proven that part of the vessel was coiled, making it irrelevant to discuss it here.

Figure 26

A picture demonstrating the two types of pressures involved in coiling (a) and

pinching and paddle and anvil (b). Note the different in the preferred orientation in

each of the example, and that the paddle and anvil as well as the pinching technique

show a similar orientation.


Page | 37

As seen in the last chapter (4.2), the x-rays of the Hellum ceramic X294 and X485 both showed

two types of production on the sherds, molding in one area and coiling in another area. This

difference in interpretation of the vessels is odd, especially since it can be assumed that the original

study had unfettered access to the sherds from the excavation, and, therefore, would have had more

chances to study all of the vessels rather than a sample, which is was available to the author. The

big difference in the original study and this newer study is that, apart from Lindahl’s thin-section

analysis, all of the studies were done through visual examination. This is problematic as Ina Berg

has shown that there is a wide margin for error when archaeologists rely solely on this descriptive

method (Berg 2008, 2011). When comparing the x-rayed sherds from Hellum to those from

ethnographic studies of modern pottery production from the Papuan potters in which the vessels

have been pinched or paddled, there is a marked difference in the x-radiography. The paddle and

anvil shows neat, square marks in the clay with darker spots where the paddle has thinned out the

body of the vessel, meanwhile the pinching shows a consistently thinning of the vessel up to the

rim, where the clay is thickest (Fig 27). Compared to the x-radiography done on the Hellum vessels

none of them

show anything

even slightly

comparable to

the x-rays done

by Rye. The

sporadic

thickness in

some of the

sherds, such as

sherd X294

(Fig 28), do not show the marks for paddle and anvil or pinching. Instead, it shows a greater

tendency towards being molded or handmade as Ina Berg determines some of her vessels to be

(Berg 2008: p. 147 – See Plate 11(8) in source for picture of the vessel).

Figure 27

Two sherds from Owen Rye’s study of Papuan pottery, which were produced through paddle

and anvil as well as pinching. The sherd on the left was produced through paddle and anvil,

where the marks of the paddle can be seen on the vessel wall while the pot on the right was

produced through pinching. Photos after Rye 1977: p.


Page | 38

While the x-radiography appear conclusive in terms of the production, the potential to expand on

the study of the ceramics through thin-section petrography should not be ignored. While it presents

a very limited view of the vessels, the thin-sections can help support the x-radiography. For

example, for pots produced

through coiling, the coils must

be joined at some point, the

method of which is more easily

viewed in thin-section than in

the x-rays. The x-rays, as

mentioned in chapter 2, were

also crucial for improving the

cuts made during thin-section

so that the greatest amount of

information possible was

gathered from each sherd.

Again, the thin-sections

showed a different production

above the maximum vessel

diameter, with a large amount

of coiling taking place above

the maximum vessel diameter.

These coils were characterized

by the micas (biotite and

muscovite), the sillimanite, and

the other elongated inclusions in the sherd. However, below the maximum vessel diameter,

identifying the production is not as easy. The same inclusions that showed the coiling could be tied

to both the paddle and anvil and the pinching technique in the plane-polarized view (Fig 29).

However, the plan polarized light helped give a better understanding of the forming of the vessel as

the voids were more easily seen, curving with the finger marks visible on the sherds. Combined

with the x-radiography this greatly helped identifying the production technique below this

maximum diameter. It is worth mentioning that Kock’s description mention that the vessels, while

Figure 28

An image of sherd X294 from Hellum, which has been X-rayed. The

white areas represent thinner areas in the sherd while the darker

areas represent the thicker areas. What this shows is a completely

difference, between the upper and lower vessel walls. The red lines

above the crack show the coils as they appear in the x-rays,

meanwhile the light blue lines show the areas affected by moulding.

Photo after author.


Page | 39

coil built, were beaten together rather than smoothed by hand (Kock 2001: p. 95). While the coiling

is visible, the sherds themselves do not show internal finger marks from a finishing beating in the

form of finger prints, though one sherd does show a crack that Rye mentions as a characteristic of

beating (Fig 30). However, this crack is only on the inside of the vessel, and it is unlikely that a

finished coiled pot would be beaten into shape, especially on the inside.

Figure 29

Sherd X002 seen in PPL. Note how the lighter lines seen in the thin-section, inside the red circle curve with sherd

indicating a possible production through molding, Photo after author.


Page | 40

Figure 30

Sherd X003 (Top) and

X146 (bottom) from

Hellum, both pictures

show the inside of the

vessel. Note the lack

of distinctive finger

marks which have

been present on sherd

X155. Photos after

author.


Page | 41

5.3 Spread of Hellum Ware

While not a part of the original study of the Hellum kiln, part of petrography does involve also

studying the spread of the ceramics from the production site, if possible. As part of this, a member

of Nordjyllands Historiske Museum, also known as NHM gave the author two sherds, which were

found in Aalborg and which Christian Vrængmose Jensen of NHM believed to be from Hellum (Fig

31; see Appendix I for description of these two sherds). In thin-section the main variation in the

sherds was the larger concentration of muscovite as compared to the other sherds from Hellum.

The importance of

discussing the export of

the wares from Hellum,

rather than just studying

the wasters, are that,

while wasters can be

representative of the

pottery, they are still by

definition, unfinished

products and do not

represent the social

significance of the

pottery, if indeed any exists, nor what they may have been used for. The thin section did reveal

elongated voids filled with phosphorous that do point towards their use as a cooking pot. In the

chaîne opératoire they also represent the final steps of the chain, use and deposition of the sherds.

As has already been mentioned none of the sherds from Hellum selected from the boxes of sherds

made available to the author by Nordjyllands Historiske Museum were rims. Therefore, they also

potentially represent the final production before the pots were dried and fired. From the x-

radiography of X216a as well as the thin-sections of both rims sherds provided by Christian

Vrængmose Jensen, it is believed that the rims may have been coiled before being pulled into the

final shape of the rim. The coiling is visible on the body area of sherd X216a, and in thin-section

certain areas of the sherd show signs of possible coiling, though due to the curvature of the rim

sherd the x-rays are not as good as the ones from the other sherds, so it is uncertain whether or not

the rims were actually produced in this way. To be absolutely certain of the production method for

Figure 31

The two sherds from the excavation in Aalborg. The sherd on the right had part of

the body still attached to the rim, making it of special interest as it would be

possible to study if there was a difference in production between these areas as well.


Page | 42

the rimsherds from Aalborg, would require a larger x-ray machine that could study the entire sherd

in one x-ray, rather than bit by bit as was done for the x-rays in this dissertation. The two rims also

represent a challenge to the idea that pots were made and sold locally, which Alan Vince has

showed with Middle Saxon ceramics is not always the case, with these pots having a wide

distribution despite “… the unprepossessing appearance of much of the pottery.” (Vince, 1989, p.

171).

5.4 The Chaîne Opératoire

Having covered the results, and discussed

their results against the author’s own, the

next goal is to discuss how the new

information can be used to expand the chaîne

opératoire of the pottery production of

Hellum (Fig 32).

As opposed to Torksey, where the potters

had multiple clay sources to choose from, the

only source available to the potters of

Hellum was boulder clay, more specifically

the one from Siem Skov, which is more

easily formed than that of other sources from

the area, with one containing a large amount

of clay with finer inclusions that could

possibly have been mixed into the other clays

to help the workability of the other clay

sources from the area, though this is just

conjecture.

The forming process for the ceramics has been seen to be more complicated than previously

suggested by Bibby and Sell (2001), Kock (2001), and Lindahl (2001). Involving not one

overarching process, but instead smaller steps that could be easily broken up and would allow the

Figure 32

A diagram of the chaîne opératoire as seen through the

analytical methods done by the author. It is worth noting

that temper may still be added, but the temper is specific to

one type rather than all of the temper being added.


Page | 43

potter to produce more vessels. While the paddle and anvil technique does require multiple steps,

the potter cannot safely put away the globular pots once the forming process has started due to the

clay not being stable enough for the pot to be placed on its rim, as Bibby and Sell suggest (Bibby &

Sell, 2001, p. 305). While this does follow the idea presented by Sillar and Tite, where the vessels

are under a constant influence of outside sources, ranging from the shape of the vessel to the

availability of raw materials, it does bring up the question of the feasibility for a large production as

is believed to have taken place at Hellum (Ibid: p. 303). With the new results, it is seen as more

likely that the pots are molded, most likely in a bowl of some kind, and wrapped in a cloth so that

the clay does not adhere to its mold. This would fit with some of the marks seen on the outer parts

of the vessel, it would also allow for the potter to produce a large number of pots needed for the

final firing of 70 vessels. The molding would allow the bottom half of the vessel to dry slightly,

making it more stable to continue working on and shaping the upper half of the vessel through

coiling. At some points during this production, the vessel would need to dry as well to ensure the

clay did not fail when the body of the vessel narrowed towards the rim. Finally, it is possible that

the rim was coiled before being pulled into the shapes, though for now this is just conjecture and

would require further studies and better x-radiography to offer any conclusive proof.


Page | 44

5.5 Future Research Throughout this dissertation, it has been demonstrated how, through a careful study of the sherd

from both visual and archaeometric standpoints, one can expand and increase the knowledge of

products from a single kiln. This relates not only to the technological choices made during the

production of the ceramics, but also how these choices can be used to study the distribution of

sherds from outside of the kiln site. The aim of this section is to cover the future research of

ceramics in Denmark, as well as cover the use of other archaeometric methods outside of Denmark.

When looking outside of Denmark, such as in Sweden or England, it is seen that archaeometric

methods are used, whether it be thin-section petrography, SEM, or ICP. In Sweden Torbjörn

Brorsson has shown how the use of ICP can aid provenance studies with Viking age ceramics

(Brorsson, 2013, p. 61). The possibilities of using portable X-ray Fluorescence (XRF) analysis for

bulk studies of pottery and their provenance has also been discussed (Hunt & Speakman, 2014). In

both of these instances, the methods, while useful in the sense of quickly grouping ceramics, it can

be argued that they also offer a limited perspective of ceramics. In Denmark at this point, it is

believed that these methods could be used for future research to help group ceramics as both ICP

and XRF analysis are relatively inexpensive and easier to do than thin-section analysis, which

requires more training and time than the other methods. However, while x-radiography can be said

to be equally inexpensive, and can be used to group sherds it does rely on the inclusions being large

enough to be seen in x-ray and unique enough that they can be characterized (Berg, 2011, p. 58).

While the above mentioned methods do represent a different perspective of study, provenance

rather than technology, the methods used can still be of some use in regards to the future research of

ceramics in Denmark. ICP analysis has already been used by Jesper Langkilde to group sherds from

production sites as well as sites that are well dated to demonstrate that red earthen wares were

produced much earlier than previously thought (Baltic and North Atlantic Pottery Research Group,

2016). While the question in Langkilde’s study was the production of red ware, it did not consider

how the production might have changed and what characterized the production over time, as well as

whether of not this changed. This is where it is believed that the future of ceramic research in

Denmark needs to lie, and the methods used in this dissertation may lay the groundwork for that

very research.


Page | 45

However, the methods used herein still had some problems, both in terms of the geological

sampling of the Hellum areas as well as the x-radiography. The first was largely problematic due to

the low scale of the map available to the public (1:200,000). Had it not been for the low accuracy of

the map, there would probably have been more success regarding studying different types of clay

sources, expanding the knowledge of the areas and why potters may have chosen one type of clay

over another. Keeping this in mind, it would be valuable to work more closely with local geologists,

who could help with the sampling.

One factor that was only covered to a limited degree in this dissertation, but should be expanded

on for future research with this type of study, is the social aspect. Jette Linaa’s research has

considered different types of pottery against the backdrop of the social changes in the 14th to 16th

centuries. Seeing as this kiln is the earliest known and published example from the middle-ages, a

larger discussion of the ceramic production and use against the backdrop of the time could be a

useful tool for understanding the introduction and evolution of certain industries. As Aalborg is the

only known distribution point for the Hellum ceramics, further study of the city’s ceramics with

special attention paid to the production marks seen on vessels from Hellum and thin-section

petrography, would be advantageous in future studies.

Another aspect, which was briefly covered, is that, the results from the x-radiography and the

thin-section petrography could potentially help with further reconstruction of the ceramics. This is

due to there now being a way to identify sherd placement within the body. Due to this difference

being known and observable in hand specimen, it can be suggested that sherds could be grouped

into sherds that lie above and below the maximum vessel line. This grouping could result in a

further reconstruction of some vessels from the Hellum kiln.

On a final note, whether future work on Danish pottery is done in the same vein as this dissertation,

or using other methods, it is important that multiple methods are used when studying the ceramics.

Most, if not to all of the results, from this dissertation have been based on the use of multiple

analytical methods. Had it not been for the x-radiography, thin-section petrography, and finally the

visual examination the results would most certainly have been useless or pure conjecture.


Page | 46

6. Conclusion From the above study, it has been shown that through an archaeometric study, it is not only possible

to study the chaîne opératoire of ceramic production, but also study the spread of the ceramics. For

this dissertation, ceramics from Hellum kiln were used as a case study. This study did make it

possible to expand the chaîne opératoire for the products produced at Hellum in the 12th century.

From the thin-sectioning of the sherds and the clay samples, it has been possible to determine that

the clay was most likely not tempered before production, and that the production of the vessels was

more complicated than previously thought, involving molding, coiling, as well as pulling of the clay

until it was the correct shape. Along with the production of the ceramics, it was also possible to

study the distribution of two rims from Aalborg, proving that, as with the later ceramics from

Hellum, there was a trade in this type of pottery, which had hitherto not been proved.

The range of production techniques and the lack of adding temper to the clays also raises the

question of whether or not the assumptions that were made for the other industries in Denmark are

just as problematic. It also raises the question that, if all ceramic production sites are equally unique

as the ones that have already been thin-sectioned, is it possible that it is possible to introduce the

concept of wares to Denmark as has already been done in England?

While there have been provenance studies of other ceramics from Viborg, Lund, and Lejre, by Alan

Vince (Christensen, et al., 1994) as well as some sherds from Ribe (Personal Observation), little

work has been done on the ceramics produced in Denmark. This can be attributed to the lack of

petrographic research, but with the result of this dissertation it is possible to start a consideration for

a wider internal trade of ceramics from production sites. However, this will require further

discovery of kilns.

One factor that was touched upon in the discussion was the distribution of the sherds from Hellum

to Aalborg. The results show that, at least tentatively, it can be suggested that the spread of the

medieval Hellum ware went as far as Aalborg, about 35 Km away. It also shows that, despite the

moraine clays being cited as the source for the different production sites of Hellum, Barmer, and

Kragelund (Fig 33) (Kock, 2001e, p. 111; Lindahl, 2001, p. 295).


Page | 47

Figure 33

Two thin-sections

from Barmer (top)

and Kragelund

(bottom). Note that

the inclusions seen

in the thin-sections

are totally unique to

those of Hellum.

Photos after author,

thin-sections

courtesy of Anders

Lindahl.


Page | 48

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Quaternary International, Volume 405, pp. 21-30.


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Appendix I: Ceramic Descriptions All sherds in this appendix are described in accordance to firing, production marks, and any signs of

production, which are based on a description model set out in Handbuch zur Mittelalterlichen

keramik in Nordeuropa by Hartwig Lüdtke. The sherds are grouped by excavation, therefore the

two sherds from Aalborg appear last and in their own subheading. Apart from 5 sherds (X001-

X005), all the numbers given here are the original X-numbers given to the sherds by Nordjylland

Historiske Museum.


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Journal Number 1399

Journal Number 1399 Description

Find Number X177 The sherd seems to be low fired. The color

of the body varies from a dark buff to black

on the body. The outside of the sherd

appears to be smoothed. The inside of the

sherd has signs of a possible coil being

smoothed. The fabric is dark grey with some

orange clusters, it is unknown whether or not

these are clay particle. Some sections of the

sherd seem to sparkle, possible mica

inclusion.

Size (HxW) 5.5 x 7.2 cm

Thickness 0.5-0.7 cm

Sherd Form Bodysherd

Petrography Number HEL I


Page | 55


Find Number X431 The sherd seems to be low fired when tapped

against the teeth. The body color is a dark grey

throughout the sherd. The outside of the sherd

contains a small sign of a coil that has not been

smoothed on the surface; otherwise the sherd

has been smoothed completely. The inside also

contains one relic coil. The fabric varies in color

from an oxidized red to a reduced black. The

inclusions seem to be granitic with some small

clay particles.

Size (HxW) 7.4 x 5.6

Thickness 0.7-0.8

Sherd Form Body sherd

Petrography Number HEL II


Page | 56


Find Number X146 The shoulder sherd seems to be low fired when

tapped against the teeth. The outside of the

sherd has one unsmoothed coil near the

transition to the rim. The inside of the sherd

has two signs of two coils, which have not

been smoothed out. The body varies in color

from a buff to a dark grey. The fabric color

shows a similar variety with granitic inclusions

and some possible mica inclusions on the

body.

This one will be selected for photography and

X-ray


Thickness 0.7-0.9

Sherd Form Shoulder Sherd

Petrography Number HEL III


Page | 57


Find Number X142 The sherd is low fired when tapped against

the teeth. The outside of the sherd has been

smoothed, and it can be seen at the rim

transition that the smoothing has been done

evenly, possibly on a slow rotating wheel.

The inside of the sherd shows one possible

coil and a clear coil. The body color is a

homogenous buff color. The fabric is the

same color as the body with some section

being an oxidized orange color.

This sherd was taken for photography and X-

Ray

Size (HxW) 6 x 5.6

Thickness 0.9-1.0

Sherd Form Shoulder Sherd

Petrography Number HEL IV


Page | 58


Find Number X217 The sherd is low fired when tapped against the

teeth. The outside of the sherd has been

smoothed and is relatively even. The inside of

the sherd has one sign of a coil with some

unevenness towards the top. The bod color is a

dark buff color. The fabric is the same color as

the body, but one side contains some fragments

of what appears to be burnt material, though

under the microscope it looks more like melted

rock.


Thickness 0.7-0.9

Sherd Form Body Sherd

Petrography Number HEL V


Page | 59


Find Number X503 The sherd feels hard fired when tapped against

the teeth. The outside is smoothed flat. The

inside is bumpy, though marks from smoothing

are seen on the inside as well. The body color is

relatively homogenous with only small

variability in color, between black and dark grey.

The outside of the sherd also shows signs of it

having been pressed against something. The

fabric has a buff core, with some inclusions that

appear to be granitic. It is possible that the sherd

is from near the base of the vessel, but it is

uncertain at this point.


Thickness 0.6-0.9

Sherd Form Body sherd

Petrography Number HEL VI


Page | 60


Find Number X410 The sherd feels low fired when tapped against the

teeth. The outside of the sherd is a dark buff color

and completely smooth, the smoothing marks at the

top of the sherd all appear to be going the same

way. The inside of the sherd has not been

smoothed, with some signs of coils; the color is

similar to the outside of the piece. The fabric is

light grey in color, with granitic inclusions.


Thickness 0.7-0.9


Petrography Number HEL VII


Page | 61


Find Number X485 The sherd is hard when tapped against the teeth.

The outside of the sherd appears to be a buff

color and is relatively smooth with only a small

bump on the left side of the sherd. It is possible

that this sherd is the start of a shoulder for a pot.

The inside has not been smoothed and shows

the relic of a coil. The fabric is a buff color and

has some possible granitic inclusions.

This sherd was selected for x-ray.


Thickness 0.5 – 0.9


Petrography Number HEL VIII


Page | 62


Find Number X168 The sherd is low fired when tapped against

the teeth. The outside of the sherd is smooth

with a light buff color. The inside of the

ceramic is rough with some signs of fingers

being pressed into the body of the vessel.

The fabric of the vessel is not very visible as

the sherd’s corners are heavily rounded. The

inclusions seem to be mainly granitic rocks,

though these are only visible on the inside of

the sherd.




Petrography Number HEL IX


Page | 63


Find Number X418 The sherd is hard fired when tapped against

the teeth. The outside of the sherd is

completely reduced and smoothed, with

some smooth of the vessel towards the top

of the sherd. The inside of the sherd is

reduced as well, with signs of fingers being

pressed into the vessel. The fabric is an

oxidized red with granitic fragments as

inclusions.




Petrography Number HEL X


Page | 64


Find Number X471 The sherd is hard fired when tapped against the

teeth. The outside of the sherd is smooth with

some signs of inclusions being pulled out of the

body as well as some cracks. The inside of the

vessel is uneven with more cracks, towards the

bottom are two possible relic coils. The color on

the inside and outside is a buff color. The fabric

is an oxidized red color. The inclusions seem to

consist mostly of granite.

This piece will be used for X-Ray




Petrography Number HEL XI


Page | 65


Find Number X249 The sherd is low fired. The outside of the

sherd is a buff color with some small

inclusions, the outside shows signs of having

been smoothed as well. The inside of the

sherd is more uneven with possible finger

marks across the inside. The fabric is mostly

reduced with a small oxidized core, there are

some signs of shrinkage in the fabric along

with larger inclusions.




Petrography Number HEL XII


Page | 66


Find Number X428 The sherd is low fired. The outside of the vessel

has been smoothed, though no obvious marks

from smoothing are visible. The inside of the

vessel is rough towards the top, while the lower

part of the sherd is smoother. The inside also

shows a large amount of sherds and is evidence of

a variable firing. The fabric is mostly oxidized

with some parts having been reduced to a buff

color.




Petrography Number HEL XIII


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Find Number X294 The sherd is two pieces that were glued

together, both pieces are low fired. The

outside is rough, possibly due to some of the

outside body falling off. This also shows a

large amount of inclusions in the vessel as

well. The inside of the vessel shows both

finger marks as well as one coil. The color is

an even buff. The fabric is a dark reduced

color, but no inclusions are visible to the eye.

This sherd was selected for x-ray


Thickness 0.6 - 1.0


Petrography Number HEL XIV


Page | 68


Find Number X336 The sherd is low fired. The outside is has

been smoothed, though there are small

marks from where some inclusions have

been ripped out of the body. There is also a

small patch which is most likely nail polish.

The inside of the sherd is bumpy with some

signs of finger marks. The fabric is a

variable oxidized red and a buff color. The

inclusions are variable but some are large

enough to be seen. The inclusions are

mostly granite and some oxidized piece.


Size (HxW) 9.7 x 12.2



Petrography Number HEL XV


Page | 69


Find Number X155 The sherd is hard fired. The outside has

been smoothed down, and the sherd has

a varying color from grey to black. The

inside of the sherd is not smoothed,

with several possible fingermarks on

the inside. The fabric is variable in

color from a light grey to black, mostly

reduced. The inclusions are mostly

granitic with some possible clay pieces.


Size (HxW) 11.5 x 15.7

Thickness 0.6 - 0.8

Sherd Form Bodysherd/Base?

Petrography Number HEL XVII


Page | 70


Find Number X001 The piece is hard fired. The outside of the

sherd is smooth with only one small bump,

it’s a black reduced color. The inside is a

dark buff with some cracks possibly from

some inclusions. The varying thickness of

the body is very visible here with a finger

mark on the thinnest part of the sherd. The

fabric is an oxidized red with some granitic

inclusions and some possible clay inclusions

as well.




Petrography Number XVI


Page | 71


Find Number X002 The sherd is hard fired. The outside has been smoothed

down and a dark buff color. The inside has not been

smoothed, with a sign of a small piece having been

chipped off and a few coils, the color is a reduced

black. The color changes between an oxidized red

color and a reduced black color.




Petrography

Number

XVIII


Page | 72


Find Number X003 The sherd is hard fired. The outside of the

sherd is smooth with one possible coil on the

outside of the vessel. The color is a reduced

black and buff color. The inside of the sherd

has a small crack around an inclusion. The

fabric is a reduced black and grey. There are

some possible mica inclusions.



Sherd Form Should sherd

Petrography Number HEL XVIX


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Find Number X004 The sherd is hard fired. The outside is

smoothed, but the sherd is too small to say

anything general about it. The inside is

smooth as well but has a preserved coil. The

fabric is a buff color, but has several large

granite inclusions as well as visible voids,

one appears to have charred material in it.




Petrography Number HEL XX


Page | 74


Find Number X005 The sherd is hard fired. The outside is

relatively smooth with some signs of mica,

a reduced black color. The inside of the

sherd is smoothed as well and is a buff

color. The fabric is an oxidized color. The

inclusions are granitic.




Petrography Number HEL XXI


Page | 75

Journal Number 4158


Find Number X216a The sherd is hard fired. The outside of the sherd has

been smoothed, as has the inside of the sherd. The rim

is a reduced color, but this is most likely due to post

production activity, this is evident from it only being

on the outside. The inside of the sherd has a small

crack towards the bottom, which could follow a small

coil. The top of the sherd has signs of being smoothed.

The fabric is a buff color with no visible inclusions.




Sherd Form Rimsherd

Petrography Number AAL I


Page | 76


Find Number X216b The sherd is hard fired. Both sides of the sherd have

been smoothed. The upper part of the sherd has a

black color, though this is most likely due to post

production activity. The rest of the sherd is a darker

buff color and contains a clean break towards the

bottom. The fabric doesn’t contain any larger

inclusions and has a buff color.

Size (HxW) 3.5 x 10.5


Sherd Form Rimsherd

Petrography Number AAL II


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Appendix II: X-Radiography The x-rays were taken over the course of several days, and were taken with the help of Dr. Gareth

Perry, using a Nomad Pro X-Ray, a Schick CDR Elite Size 2 x-ray detector, and studied in a piece

of software called Dicom, through which the photos were exported. The figure below shows an

early setup of the x-radiography. The rest of the results from the x-rays will be shown here.

Sherds X155 as it was being x-rayed by Dr. Gareth Perry.


Page | 78

X155 This sherd is the one pictured above, the x-

rays proved to be useless because the sherd

curved too much, and, therefore, could not

be sewn together effectively in 2D. The

individual pictures do indicate molding of

the vessel.


Page | 79

X142

X142 is a

shoulder sherd

and shows

coiling all the

way down the

sherd. The cracks

in the sherd,

visible in the x-

ray are also a

good indication

of coiling.


Page | 80

X485

A sherd from the

middle of the

body, the white,

horizontal line

indicates a

change in

production from

molding to

coiling. This is

similar to what

was observed in

sherd X294 but

on a smaller

scale.


Page | 81

X294

This sherd

showed the same

signs of

production as

X485, with the

areas below the

crack showing

molding and

above the crack

showing coiling.


Page | 82

X216A

This is one of the

rim sherds from

Aalborg. The

lower area show

signs of coiling,

while some of the

upper areas could

show pulling as

the inclusions run

in straight lines.


Page | 83

X336

This sherd mostly

failed, it may be

because the

exposure was too

high on this sherd to

be effective. The

inclusions in this

sherd did not aid the

study of this sherd

either, with one

picture being

stretched, marked

with a grey circle.


Page | 84

X002

Another shoulder

sherd, which only

required two

pictures. This sherd

shows several

horiztonal voids,

which could also be

an indication of

coiling.


Page | 85

Appenix III: Ceramic Thin Sections It is worth noting that the main difference in the ceramics is found in the area of the vessels max

diameter before curving in towards the shoulder and the rim. Below this max diameter, the vessels

are believed to have been pressed into a mold or form. This differs above the max vessel diameter,

where the vessels are coiled to the top of the shoulder, not much can be said about the rims as none

were available from the kiln site. If the two sherds from Aalborg are from Hellum it would appear

that a final coil was added to the top of the shoulder and then squeezed into the shape of the rim,

A differentiation between coarse and fine fraction was not used in these descriptions. Normally this

is used to indicate a difference in sherds where it is believed that there is a bimodal distribution,

which can indicate the tempering of a vessel. As part of the study, clay samples were also studied.

However, the descriptions used for these samples will differ from the normal description. This is

due to the voids and micromass not being useful in terms of forming.


Page | 86

Fabric Descriptions of the Hellum Ceramics

Fabric name

o Diorite Fabric

Micromass

o The voids in the micromass are generally either vughs or vesicles with a few

channels voids in the matrix. They measure from 0.24 mm to 1.44 mm in length,

some of the longer voids do follow the border of the thin section. The voids are

single-spaced.

Groundmass or matrix

o The matrix shows optical activity. The color varies in color from dark brown and

orange in XP to a light brown and orange color in PPL. The only exception is Slide

16 which is an almost black color in XP to light brown in PPL. The clay is

heterogeneous and non-calcareous.

Inclusions

Quartz

The quartz inclusions appear throughout the sherds in both high and

low sphericity, though are more common as equant and angular or

sub-rounded pieces. They appear as unimodal throughout the thin-

sections. As an inclusion they are frequent ranging in size from 0.08

t0 1.68 mm with a mode size lying between 0.24 – 0.32 mm.

Microcline

The sizes of the microcline range in size from 34 to 90 µm. They are

characterized by their tartan twinning in XP as well as their shape,

which is low in sphericity ranging in shape from very angular to sub-

angular pieces. The appear frequently in the matrix of the sherds, in

some instances they are connected to quartz inclusions, see slide 19.

Plagioclase

These inclusions appear as angular to sub angular inclusions with a

wide range of sphericity. They range in size from 0.08 to 1.00 mm

with a mode of 0.32 – 0.40 mm.


Page | 87

Biotite

The biotite appear throughout the thin sections as tabular laths,

ranging in size from 0.15 to 1.50 mm. With a mode of 0.32 – 0.40

mm. The only slide where they are not seen is slide 4.

Perthitic

The perthitic inclusions appear normally in thin-section as angular to

sub-angular inclusions with a high sphericity. They range in size from

0.20 to 1.50 mm with the mode being 0.4-0.5 mm in length. Slide 4

has one perthite which is quite large

Sillimanite

These inclusions appear as tabular laths, ranging in size from 0.08 to

1.90 mm with a mode of 0.30 – 0.35 mm.

Myrmekitic

These inclusions appear as angular to sub-angular inclusions with a

low sphericity. The size of the inclusions ranges from 0.20 to 1.60

mm with a mode of 0.30 mm.

Pyroxene

They appear as sub-angular sub-rounded pieces with a low sphericity

and range in size from 0.01 mm to 0.32 mm in size with a mode of

0.1 mm.

Comment

o It is worth nothing that the biotite inclusions in the thin-sections studied here are the

best indication for the different production methods seen in slide 18 (X485). These

appear parallel to the vessel walls in the lower part of the vessel but curve with the

coils in the upper part of the vessel. The same is true of slide 22 and 23 which are

X294 (bottom) and X294 (Top) respectively.

o Three of the sherds in these thin-sections also had a considerably finer inclusion set

than the other sherds of this group. Due it only being three sherds and there is no

evidence of these sherds being produced differently than the other it is noted as a

possible sub-group of the production.


Page | 88

Fabric Description of Two Rims from Aalborg

Fabric name:

o Diorite Fabric

Micromass

o The voids appear as vughs throughout the fabric ranging in size from 0.32 mm to

2.14 mm. The elongated voids and inclusion do follow the walls of the vessel, except

in a few places, which could be the result of coiling on the neck.The inclusions are

roughly single-spaced though close-spaced in other areas.

Groundmass

o Both slides are optically active. The color ranges from dark orange to brown in XP to

a dark brown color in PPL. The clay is quite heterogeneous with signs of poorly

mixed clay throughout the body; these are more visible in PPL.

Inclusions

o Quartz

The pieces of quartz in both of the slides is mostly angular to sub-angular,

with some pieces of quartz being multicrystaline. A handful of the inclusions

do appear as low sphericity, though most of the inclusions are medium to

high sphericity. The inclusions range in size from 0.92 mm to 1.20 mm with

a mode of 0.56 mm.

o Microcline

The microcline seen in the sherds range in size from 0.12 mm to 0.90 mm

and are generally sub-angular in shape with a high sphericity, the mode size

is 0.30 mm. They are characterized by their tartan twinning, which happens

throughout both slides.

o Plagioclase

The plagioclase appears as sub-angular and angular inclusions with the size

ranging from 0.24 mm to 1.12 mm, with a mode size of roughly 0.32-0.35

mm.


Page | 89

o Sillimanite family

The sillimanite inclusions in these sherds measure in length from 1.76 mm to

0.16 mm in length. They are angular in shape and tabular in form, which

helps when trying to determine the production of the vessel.

o Biotite

The biotite in these sherds appear as tabular laths that range in size from 0.40

mm to 0.88 mm with a mode of 0.30 mm.

o Pyroxene

As in the ceramic thin-sections they appear rarely as sub-rounded pieces with

medium to low sphericity and range in size from 0.12 mm to 0.24 mm.

o Hornblende

Appear as two rounded pieces, one in each slide, with a max of 0.56 mm

measurement and a minimum of 0.26 mm.

Comment

o It is believed that these two rims are from the Hellum kiln as they have roughly the

same size and types of inclusions as seen in the sherds from Hellum. It should be

noted that, because there are only two sherds in this group, that the descriptions must

be taken with great caution as a larger study of the sherds could provide more insight

into the makeup of the sherd group

o It is also worth mentioning that, while it does appear that some areas are “coiled”

much of the curvature that would indicate a coil is mainly inclusions or voids being

“wrapped” around dry pieces of clay (as seen in slide 24) with the sherds or

curvature at the bending of the rim. Slide 6 does show something that could possibly

be a coil, but this is at the end of the sherd, so may not be an actual indication of

coiling.


Page | 90

Fabric Descriptions of Clay Samples

Fabric name

o Igneous Fabric

Groundmass

o The groundmass is optically active, but it is limited to small areas of the sherd. The

color is an oxidized red in XP and abrown in PPL. The groundmass that it is visible

is homogenous and non-calcareous.

Inclusions

o Quartz

The quartz inclusions in the thin sections are the most common mineral seen,

and range in size from 0,06 mm to 1,10 mm, and mainly high in sphericity

ranging in shape from angular to rounded. Some of the inclusions are

elongated and appear as both rounded and sub-angular minerals.

o Microcline

The microcline in the thin sections of this group range in size from 0.16 to

1.44 mm. The inclusions are sub-angular and sub-rounded with a high

sphericity. The mode of these inclusions 0.24 – 0.32 mm.

o Plagioclase

These inclusions appear as sub-angular and range in size from 0.24 to 0.48

mm with a mode of 0.32 mm.

o Myrkitic

The sherds are sub-angular with a high sphericity and range in size from 0.24

mm to 0.72 mm with mode 0.32 mm.

o Perthite

The inclusions are sub-rounded with a high sphericity and range 0.32 mm to

0.72 mm with a mode of 0.32 mm

Comment

o It is worth mentioning that in these thin-sections, an attempt has been made to

describe just the groundmass and inclusions, seeing as any description of the

micromass would be useless. Due to the absence of biotite in these thin-sections, it is

not likely that these samples may be the clay used for the ceramics from Hellum.

DISSERTATION/REPORT COVER SHEET · 2017. 3. 14. · The Department Of Archaeology....

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