저 시-비 리 2.0 한민

는 아래 조건 르는 경 에 한하여 게

l 저 물 복제, 포, 전송, 전시, 공연 송할 수 습니다.

l 차적 저 물 성할 수 습니다.

다 과 같 조건 라야 합니다:

l 하는, 저 물 나 포 경 , 저 물에 적 된 허락조건 명확하게 나타내어야 합니다.

l 저 터 허가를 면 러한 조건들 적 되지 않습니다.

저 에 른 리는 내 에 하여 향 지 않습니다.

것 허락규약(Legal Code) 해하 쉽게 약한 것 니다.

Disclaimer

저 시. 하는 원저 를 시하여야 합니다.

비 리. 하는 저 물 리 목적 할 수 없습니다.

이학석사학위논문

Provenance of Lower Cretaceous Sindong Group sandstones determined

by scanning electron microscope-cathodoluminescence analysis and

Zr/Hf ratio of detrital zircon

SEM-CL 분석법과 쇄설성 저어콘의 Zr/Hf 비를 이용한 전기백악기 신동층군

사암의 기원지 연구

2012 년 8 월

서울대학교 대학원

지구환경과학부

이주현

Provenance of Lower Cretaceous Sindong Group sandstones determined

by scanning electron microscope-cathodoluminescence analysis and

Zr/Hf ratio of detrital zircon

SEM-CL 분석법과 쇄설성 저어콘의 Zr/Hf 비를 이용한 전기백악기 신동층군

사암의 기원지 연구

지도교수 이 용 일

이 논문을 이학석사학위논문으로 제출함 2012년 8월

서울대학교 대학원 지구환경과학부

이주현

이주현의 이학석사학위논문을 인준함 2012년 6월

위 원 장 (인)

부위원장 (인)

위 원 (인)

Provenance of Lower Cretaceous

Sindong Group sandstones determined by scanning electron microscope-

cathodoluminescence analysis and Zr/Hf ratio of detrital zircon

A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science in

Earth and Environmental Sciences

Seoul National University

JOOHHYEON YI

August, 2012

i

Abstract

Provenance of the Lower Cretaceous Sindong Group sandstones in the Gyeongsan

Basin was investigated. For the provenance study, the framework composition of

sandstones, the scanning electron microscopy – cathodoluminescence (SEM-CL)

technique on single quartz grains, and the Zr/Hf ratio of single zircon grains were

analyzed. Observations of quartz grains using SEM-CL images with high

magnification and resolution have shown various microstructures. Also, Zr/Hf ratio

of single zircon grains are separated into the mantle-derived anorogenic magmatic

zircons and the crust-derived orogenic magmatic zircons These microstructures and

ratio are classified for detrital quartz and zircon grains of different origins.

Deposition of the Sindong Group was initiated in a basin probably formed by

strike-slip movement in the eastern continental margin of Asia during the Early

Cretaceous. Changes in geology of the source part during this time were not much.

During the deposition of the Sindong Group, rocks of upper crustal component

such as granitic/gneissic rocks and meta-sedimentary rocks were distributed in the

source part (Precambrian granitic-gneiss, Paleozoic meta-sedimentary rocks,

Triassic granitic rocks, and Jurassic granitic rocks). The Hasandong and Jinju

formation contains some detritus from volcanic rocks, but the source volcanic

rocks have not been found either within or marginal to the basin. However,

characters of the volcanic rocks as incipient continental-arc volcanic rocks and

ii

timing of eruption were recorded in the Hasandong and Jinju formations. Also,

some source rock of the Nakdong Formation in the northern part was Triassic

anorgenic granitic rock.

Keyworlds : SEM-CL analysis, Sindong Group, sandstone, provenance, zircon,

Zr/Hf ratio

Student Number : 2010-23137

iii

Table of contents

Abstract …….……………………………………………… i

Table of contents …………………………………………. iii

List of tables ………………………………………….…… v

List of figures …………………………………………….. vi

1. Introduction ………………………………………….... 1

2. Geological Setting ……………………………………... 4

3. Method ……………………………………………... 10

3.1. Sample collection ……………………………… 10

3.2. Sandstone petrography ……………………….... 10

3.3. SEM-CL analysis ………………………………. 11

3.4. EPMA analysis …………………………………... 12

4. Results ………………………………………………... 13

4.1. Detrital composition ………………………….… 13

iv

4.2. Monopanchormtic SEM-CL analysis of quartz …. 16

4.3. Zr/Hf ratio of detrital zircon …………………….. 22

5. Discussion …………………………………………….. 24

5.1. Provenance from petrography ..………….………. 24

5.2. Provenance from SEM-CL analysis ...…..…………. 25

5.3. Provenance from Zr/Hf ratio of detrital zircon .…. 29

5.4. Probable sources ..……………………………….. 36

5.5. Spatial and temporal source rock changes ...…….. 37

6. Conclusions .……………….…………………………. 40

References ……………………………………………… 42

Abstract (In Korean) ....…………………………………. 64

v

List of tables

Table 1. Sample location of the Sindong Group sandstones in Gyeongsang Basin. .… 54

Table 2. Description of SEM-CL characteristics and features. …………................…. 56

Table 3. Quartz types identified by their SEM-CL characteristics and features. .…...…. 57

Table 4. Point count data from the Sindong Group sandstones. .……………………….. 58

Table 5. SEM-CL modal counting data and percentage of detrital quartz grains from the Sindong Group sandstones. …………………………………………………… 60

Table 6. The Sindong Group detrital zircons divided by the mantle-derived anorogenic magmatic and the crust-derived orogenic magmatic zircon ………………… 62

Table 7. Kolomogorov-Schmirnoff P-values for the zircon Zr/Hf ratios in the studied Sindong Group samples. ……………………………………………………… 63

vi

List of figures

Figure 1. Geologic map of the (A) Gyeongsang Basin and (B) Yeongnam Massif. …... 5

Figure 2. Stratigragraphy of the Gyeongsang Supergroup. ……………………………. 6

Figure 3. Ternary diagram (A) showing classification of the Sindong Group sandstones and (B) QFL ternary provenance diagram. …………………………………….... 14

Figure 4. Quartz discrimination plot with discrimination fields. …………………….. 15

Figure 5. SEM-CL images of plutonic quartz. ……………………………………….. 17

Figure 6. SEM-CL images of volcanic quartz. ………………………………………. 18

Figure 7. SEM-CL images of low-grade metamorphic quartz. ………………………. 19

Figure 8. SEM-CL images of medium-grade metamorphic quartz. ..……..………….. 20

Figure 9. SEM-CL images of high-grade metamorphic quartz. …………………….... 21

Figure 10. Bar plot in the Sindong Group sandstones form northern parts, as determined by SEM-CL analyses. ………………………………………………………... 26

Figure 11. Bar plot in the Sindong Group sandstones form central parts, as determined by SEM-CL analyses. ……………………………………………………….. 27

Figure 12. Bar in the Sindong Group sandstones form southern parts, as determined by SEM-CL analyses. ………………………………………………………... 28

Figure 13. Comparison of the Zr/Hf ratios of zircons from different genetic types (crustal -derived or mantle-derived) of granotoids. ………………………………... 31

Figure 14. Histograms and spectra of Zr/Hf ratio of detrital-zircons of the northern part. ………………………………………………………………………………. 32

Figure 15. Histograms and spectra of Zr/Hf ratio of detrital-zircons of the middle part. ………………………………………………………………………………. 33

Figure 16. Histograms and spectra of Zr/Hf ratio of detrital-zircons of the southern part. ………………………………………………………………………………. 34

Figure 17. Linkage of each formation by K-S test (p≥0.05) of detrital zircon Zr/Hf ratio for the Sindong Group samples. …………………………………………….... 35

1

1. Introduction

The Lower Cretaceous Sindong Group in the Gyeongsang Basin (Fig 1) is a

nonmarine sedimentary basin formed in the southeastern part of Korea. It was

formed probably by strike-slip movement that occurred in the eastern continental

margin of Asia. Sandstones in the Sindong Group record the changes in geology of

the source part during sediment filling in the basin, and provenance of sandstones

is investigated in this study.

Sandstones are the product of combined processes of weathering, erosion,

transport and sedimentation (Gotte and Richter, 2006). Unstable detrital grains are

disintegrated through mechanical and chemical processes. In addition, diagenesis

may remove or alter weak grains during burial. Thus, all these processes can

modify sandstone compositions, and result in final sandstone compositions

different from original ones (Johnson, 1993; Lee and Lim, 1995). Therefore, the

petrographic composition of sandstones does not necessarily correlate with the

tectonic setting (Suttner et al. 1981; Potter, 1994). Hence, sandstone, especially

mature quartz arenite, does not necessarily have to be composed of quartz grains

transported from the interior of a craton, and it does not have to be deposited along

a passive margin setting (Gotte and Richter, 2006; Augustsson et al, 2011)

In arenites, characterization of quartz particles is of special interest. Different

quartz types can be distinguished by means of colour, mineral and/or fluid

inclusion, deformation structures, and in particular cathodoluminescence (CL)

2

proporties (Fuchtbauer, 1988). In the case of CL, luminescence colour and internal

fabric are the most important features that have previously been used. (Zinkernagel,

1978; Fuchtbauer et al.,1982; Matter and Ramseyer, 1985; Seyedolali et al., 1997;

Gotze and Zimmerle, 2000; Boggs et al., 2002; Kwon and Boggs, 2002; Bernet and

Bassett, 2005; Bernet et al., 2007). The SEM-CL technique on single quartz grains

discriminates quartz types of plutonic, volcanic, and metamorphic origin (Boggs et

al., 2002; Kwon and Boggs, 2002; Bernet and Bassett, 2005; Bernet et al., 2007).

Zircon is one of the most stable minerals commonly found in rocks (Marchall,

1967; Morton, 1985; Owen, 1987). Zircon is a zirconium silicate, ZrSiO4, with

variable amounts of hafnium (Hf), which occupies part of the octahedral sites.

Zr/Hf ratio of zircon is useful for source characteristic because types, compositions,

or differentiation series of magma decide on Zr/Hf ratio of zircon. In addition,

zircon survives erosion, transportation, deposition, and diagenesis. Therefore,

sandstones may contain zircons from a variety of ultimate source rocks.

Several researchers have examined the provenance of the Sindong Group on the

basis of modal analysis of detrital framework components (Choi, 1986; Koh, 1986,

Koh and Lee, 1993) and mudrock geochemistry (Lee and Lee, 2003). However, the

SEM-CL analysis of quartz grains and Zr/Hf of zircon grains of sandstone have not

been applied for studying provenance of Sindong Group.

The purpose of this study is to demonstrate the provenance-discriminatory

potential of combining various studies on quartz and zircon. Both minerals

typically are formed in felsic crystalline rocks. Therefore, a correlation exists in

3

provenance information gained from the two minerals and petrographic data. And,

this study evaluates implications for the nature and spatial and temporal evolution

of the source regions in the Sindong Group.

4

2. Geological Setting

The Gyeongsang Basin is a non-marine sedimentary basin formed in the

southeastern part of Korea during Early Cretaceous time (Fig. 1). The Cretaceous

rocks in the Gyeongsang Basin are divided into four Groups based on volcanism

and plutonism (Chang, 1975). They are, from oldest to youngest, the Sindong,

Hayang, Yucheon, and the Bulguksa intrusive rock Groups (Fig. 2.).

The lowermost Sindong Group was deposited along the western margin of the

present basin, termed the Nakdong Trough (Chang, 1987). The Sindong Group is

underlain unconformably by the crystalline basement on the west and northern side

and is overlain conformably by the Hayang Group to the east. The Sindong Group

is 2–3 km thick, and consists mainly of sandstone and mudstone, with minor

amounts of conglomerate and marl. The Sindong Group is divided, in ascending

order on the basis of lithologic features including rock color, into the Nakdong

(alluvial fan to fluvial deposits), Hasandong (fluvial deposits), and Jinju (lacustrine

deposits) formations with decreasing age (Chang, 1975; Choi, 1981). The Nakdong

Formation is ~550 m thick, but thickens northwards. The lowermost part of the

formation consists of mid-fan conglomerates overlain by distal-fan sandstones

intercalated with dark gray mudstones and black shales. The alluvial fan deposits

grade upwards into fluvial plain deposits, which are composed mainly of an

alternation of channel sandstones and inter-channel dark gray mudstones and

5

Figure 1. (A) Geologic map of the Gyeongsang Basin (modified after lee and lee, 2000) and (B) geological map of the central Yeongnam massif and Okcheon belt (modified after Sagong et al., 2005) Granitoids ages from previous studies (Turek and Kim, 1995; Kim et al., 2003; Sagong et al., 2005; Part et al., 2005; Lee et al., 2005; Park et al., 2006)

(A) (B)

Middle part

Northern part

Southern part

6

Group Unit Age

Yucheon Group

Volcanic rocks Campanian~

Goesong Formation

Hayang Group

Jindong Formation

Geoncheonri Formation Turonian~ Santonian

Cheyaksan Volcanics

Cenomanian Sonnaedong Formation

Banyaweol Formation

Haman Formation

Albian

Hakbong Volcanics

Silla Conglomerate

Chilgok Formation

Sindong Group

Jinju Formation

Hasandong Formation

Nakdong Formation Aptian

Basement rocks

Figure 2. Stratigragraphy of Gyeongsang Supergroup (modified after Chang, 1987). Sindong Group is the lowermost part of the Gyeongsan Supergroup.

7

siltstones (Choi, 1981). The Hasandong Formation, approximately 1100 m thick, is

similar to the uppermost part of the Nakdong Formation in that it consists of

alternating channel sandstones and inter-channel fine deposits, but shows

characteristic red beds containing calcareous nodules (Lee, 1999b). The Jinju

Formation is about 1200 m thick, and is made up mainly of dark gray to black

lacustrine mudstones, deeper open lake black shales and channel sandstones. Most

Sindong sediments were derived from Precambrian gneisses and Jurassic granites

located to the west and northwest (Koh, 1974). However, the upper half of the Jinju

Formation contains a significant amount of volcanic detritus (Choi, 1986; Noh and

Park, 1990). Sediments were derived from both the volcanic and plutonic–

metamorphic provenances (Lee and Lee, 2000b).

Paleocurrent studies indicate that the mean direction of sediment transport was

toward the east and southeast (Chang and Kim, 1968; Koh, 1986). Studies on

Charophyta (Seo 1985; Choi, 1987, 1989) and spores and pollen (Choi, 1985; Choi

and Park, 1987) suggest that the Sindong Group was deposited during the late

Valanginian–Barremian, respectively. However, absolute age measurements for the

Sindong Group was deposited during the late Aptian to late Albian, which is

younger than previously thought (Lee et al., 2010)

The paleolatitude of the Gyeongsang Basin during the Early Cretaceous was ~5°

higher than that of the present day (Park et al., 2005). Occurrence of gypsum

pseudomorphs, ooids and stromatolites in the Hasandong and Jinju formations

indicate that the regional climate was dominantly arid to semiarid during

8

deposition of the Sindong Group (Woo et al. 1991; Paik and Lee 1994, 1995).

Other lines of evidence for the aridity of the climatic conditions include calcretes

and vertic paleosols developed on the floodplain deposits of the Hasandong

Formation (Paik and Lee, 1998; Lee, 1999). Choi (1985) also suggested that spore

and pollen assemblages in the Jinju Formation indicate arid climate. In contrast,

Choi (1999) suggested that the Nakdong alluvial fan deposits were deposited under

a humid climate, which is supported by the presence of coaly mudstones (Cheong

& Kim, 1996) and fern fossils (Cheong & Paik, 1992).

The Precambrian rocks in the basement Yeongnam massif comprise biotite

granitic gneiss, leucocratic granitic gneiss, quartz-feldspar gneiss, and

porphyroblastic granitic gneiss. These rocks are collectively treated as granitic

gneissose. The granitic gneissose is usually medium- to coarse-grained biotite

metagranite consisting of quartz, plagioclase, biotite, and microcline, and small

amount of sillimanite, muscovite, myrmekite, kyanite, and zircon. Quartz crystals

show strong wavy extinction (Won and Kim, 1969; Yoon et al., 1988).

Jurassic granites (197-158 Ma) with sparsely distributed Middle to Late Triassic

granites (248-210 Ma) are abundantly distributed in the Precambrian Yeongnam

massif (Cho et al., 2001; Kim et al., 2003). The age structure of the granites was

closely related to temporal changes in relative plate motion of the oceanic Izanagi

plate with respect to the eastern Eurasian continent during the Mesozoic (Jwa,

2004). The Triassic granitoids formed as a result of subduction-related primitive

arc magmatism, and reflect assimilation of crustal material, and the Jurassic granite

9

formed in a calc-alkaline continental arc environment. (Cheong and Chang, 1996a,

1996b, 1997; Kim et al., 2005)

10

3. Method

3.1. Sample collection

About thirty sandstone samples from the Sindong Group, three different parts of

the Sindong Group distribution area (northern, middle, and southern parts) were

collected from roadcut or valley.

3.2. Sandstone petrography

Thirty thin sections of fine- to medium-sized Sindong Group sandstones were

analyzed to obtain modal composition by counting 300 points in each thin section

(Table 4).

The characteristics of the detrital quartz grains were examined on the basis of

polycrystallinity and undulosity by counting of quartz types as monocrystalline

quartz with nonundulose and undulose extinction (Qnu and Qu, respectively),

polycrystalline quartz of two or three subcrystals (Q2-3), and polycrystalline quartz

of more than three subcrystals (Q>3) following after Basu et al. (1975) and Tortosa

et al. (1991).

11

3.3. SEM-CL analysis

The principal focus of the provenance analysis was the use of scanning electron

microscope cathodoluminescence (SEM-CL) image on quartz grains. Analysis was

performed on twenty seven polished and carbon-coated thin sections under JEOL

JSM-6380 SEM equipped with an Oxford Instrument mirror-type CL detector at

Seoul National University. The CL detector detects luminescence in the 180-850

nm wavelength range. Digital images were taken at 10.0 nA beam current and 15.0

kV acceleration voltage with an average working distance of 15 mm. More than

200 quartz grains per thin section were identified by using an Oxford energy-

dispersive spectrometer (EDS) attached to the SEM. Images were taken at 1280

pixel average, which corresponds to a scan time of 160 seconds. In general, images

were enhanced afterwards with a commercial photo editing program.

Bernett and Bassett (2005) established a reference data base of quartz types using

combined SEM-CL and optical petrography on the same crystals. Table 2 provides

a description of SEM-CL characteristics and features used in SEM-CL analysis.

Table 3 describes quartz types identified by their SEM-CL characteristics and

features.

Quartz luminescence may result from Al substitution for Si, intracrystalline

variation in trace-element concentrations, or linear or point defects in the quartz

crystal structure (Perny et al., 1992; Watt et al., 1997; Ramseyer and Mullis, 2000;

Stevens-Kalceff et al., 2000). Quartz crystals can contain a variety of textural

12

features such as defects in the crystal structure (e.g., microcracks, healed cracks,

microfractures deformation lamellae etc.) or zoning, which may be visibly

enhanced because of variation in luminescence within the crystals (Table 2).

However, quartz crystals low in defects or intracrystalline chemical variation (trace

elements, etc.) can appear homogeneous in light gray to black with no variation in

CL intensity (e.g., Boggs et al., 2002). Note that light gray, dark gray or black are

only relative terms used here just to describe CL appearance in panchromatic

images. Black CL does not mean nonluminescence, but can actually be dark red in

color CL images. High and low luminescence are as well descriptive terms used in

a similar way, where high luminescence corresponds to bright white or light gray

and low luminescence with dark gray or black CL in panchromatic SEM-CL

images (Bernett and Bassett, 2005).

3.4. EPMA

Electron probe microanalysis (EPMA) was carried out for two elements, Zr and

Hf of detrital zircon grains with a JEOL JXA 8900R microprobe at NCIRF, Seoul

National University. Operation conditions was a 15kV accelerating voltage, 110

nA sample current , 10 μm spot size, and 100s count time.

A total of 631 detrital zircon grains were analyzed from nine sandstone samples

(one sandstone sample from each formation at each part).

13

4. Result

4.1. Sandstone Petrography

The sandstone compositions of the Sindong Group sandstones are shown in Table

4 and are plotted on Dickinson’s (1985) provenance discrimination diagram and

Folk’s (1968) diagram (Fig. 3). Sandstones are generally rich in quartz and feldspar

and plot in the transitional continental block. Exceptions are sandstones from the

upper Jinju Formation of the middle and southern parts, which are rich in lithic

fragments but poor in quartz, in which lithic fragments are dominated by volcanic

rock.

Classification of Sindong Group sandstones reveals that Nakdong, Hasandong,

and Jinju sandstones belong to subarkose, arkose, and lithic arkose, respectively

(Fig. 3). As shown by Fig. 3(A), they vary from quartz-rich sandstone to feldspar-

and rock fragment-rich lithic arkose to ascending order.

Quartz grains comprise, (27 to 83 % of framework grains with a mean of 64%)

are mainly monocrystalline and the modal percentage of it decreases in ascending

stratigraphic order (Fig. 3). Quartz types are mainly monocrystalline (Qm) and

polycrystalline (Qp) with evident inclusions and undulatory extinction, suggesting

these quartz grains being originated from a metamorphic region (Fig. 4). The

presence of monocrystalline quartz (inclusionless and with uniform extinction) and

14

Figure 3. Ternary diagram (A) showing classification of Sindong Group sandstones (after Folk, 1968), (B) QFL ternary provenance diagram (after Dickinson, 1985)

L

Qt

F

Nakdong Fm.Hasandong Fm.Jinju Fm.

craton interior

transitional continental

basement uplift

recycled orogen

dissected arc

transitional arc

undissected arc

(A) (B)

L

Qt

F

Nakdong Fm.Hasandong Fm.Jinju Fm.

quartzarenite

subarkose

sublitharenite

arkose lithic arkose

feldspathic litharenite litharenite

15

Figure 4. Quartz discrimination plot with discrimination fields from (A) Basu et al. (1975) and (B) Tortosa et al. (1991) for medium-grained sand. Lower triangle is used when >25% of the polycrystalline quartz grains are composed of more than three subgrains. Qm<5° = monocrystalline quartz with < 5° undulosity, Qm>5° = Qm with > 5° undulosity, Qp, 2–3 = polycrystalline Q with two or three crystals, Qp, >3 = Qp with more than three crystals.

Qp 2-3

Qm<5°

Qm>5°

Qp >3

Granites

Slates & Schists

Qp 2-3

Qm<5

°

Qm>5°

Qp >3

(A) (B)

16

feldspar suggests a felsic plutonic source. The presence of elongate and

polycrystalline quartz grains with preferred orientation suggests their derivation

from metamorphic rocks. Plagioclase is more abundant that K-feldspar. Feldspar

grains are subangular and show albitization and replacement.

The relative percentage of various lithic fragment types shows dramatic changes.

Although metamorphic rock fragments dominate in the northern part, a pronounced

characteristic of the other lithic fragments is the abundance of volcanic rock

fragments in the Jinju Formation in Middle and southern parts. Volcanic lithic

fragment are slightly altered and are predominated by lathwork type.

4.2. Monochromatic SEM-CL analysis of quartz

Over 200 SEM-CL images of quartz grains from each sample were examined in

this study (Table 5). The criteria of Seyedolali et al. (1997) and Bernet and Bassett

(2005) were used to interpret the provenance of quartz grains in samples of

eighteen sandstones from Sindong Group. Fig. 5 shows plutonic quartz grain with

typically randomly oriented microcracks and healed cracks. Fig. 6 shows CL

images of detrital volcanic quartz grains; note the embayed outline and large open

crack of the grain, although zoning was not showed. Fig. 7 shows low-grade

metamorphic quartz from brittle deformation that displays oriented microfractures

and healed fractures. Fig. 8 shows medium-grade metamorphic quartz from a set of

17

Figure 5. SEM-CL images of plutonic quartz showing typically randomly oriented microcracks and healed cracks.

18

Figure 6. SEM-CL images of volcanic quartz showing embayment and large open cracks.

19

Figure 7. SEM-CL images of low-grade metamorphic quartz showing oriented microfractures from brittle deformation.

20

Figure 8. SEM-CL images of medium-grade metamorphic quartz showing a set of deformation band lamellae due to ductile

deformation and patchy CL response or mottled CL texture due to partial recrystallization.

21

Figure 9. SEM-CL images of high-grade metamorphic quartz showing black and homogeneous CL from recrystallization.

22

deformation band lamellae due to ductile and patchy CL response or mottled CL

texture due to partial recrystallization. Fig. 9 shows a high-grade metamorphosed

grain that display black and homogeneous CL features from recrystallization.

The results of the SEM-CL analyses of quartz in Sindong Group sandstone samples

are summarized in Fig. 10 (northern part), Fig. 11 (middle part), and Fig. 12

(southern part). SEM-CL analysis shows that 38~80% of the quartz grains of

metamorphic origin, 19~50% are derived from plutonic source rocks, and 0~24%

show characteristics of volcanic quartz (Fig. 12). Metamorphic quartz

predominates in sandstones from all formations inspective of sampling locations.

Plutonic quartz also exists in large amount in all formations identified but volcanic

quartz occurs in minor amounts. Because few recycled grains were shown and

quartz grains were mostly angular to sub-angular, these data provide a reliable

estimate of the proximate source of the quartz grains.

4.3. Zr/Hf ratio in detrital zircon

The similar ionic radii and electrical charges of Hf and Zr result in a systematic

and isomorphic substitution between these two elements (Rama-krishnan et al.,

1969). In most silica-saturated igneous rocks, zircon is the chief mineral containing

Hf. Thus, the Zr/Hf ratio of the mineral is often considered to be close to the ratio

in the magma (Vlasov, 1966).

The electron microprobe analysis shows that the Sindong Group detrital zircons

23

are separated into the mantle-derived anorogenic magmatic zircons and the crust-

derived orogenic magmatic zircons (Table 6, Fig. 14, 15, 16).

24

5. Discussion

5.1. Provenance from petrography

The proportions of framework grains of the Sindong Group sandstones suggest

their derivation from geologically heterogeneous sources. Input from several

distinct lithologies can be identified. The high proportions of monocrystalline

quartz with non-undulose extinction and plagioclase, mostly oligoclase, suggest

that considerable amounts of detrital grains were derived from felsic plutonic rocks.

Also, the occurrence of polycrystalline quartz, plagioclase, and metamorphic lithic

fragments (quartz-mica schists and slate fragments) indicate a contribution of

detritus from a metamorphic terrane (Lee and Lee, 1998; Lee and Lim 2008).

Although minor, the presence of volcanic lithic fragments suggests that volcanic

rocks were exposed in the source area.

On the QFL ternary diagram of Dickinson et al. (1983), the Sindong Group

sandstones fall mainly within transitional continental block field, and some upper

Jinju Formation sandstones are plotted in the magmatic arc filed (Fig. 3).

Quartz polycrystallinity plotted together with extinction characteristics following

the technique of Basu et al. (1975) indicates a metamorphic source (Fig. 4).

Samples mainly plot in the low to medium-grade metamorphic field. This result

indicates that the majority of the quartz grains were derived from low to medium-

grade metamorphic rock source. However, the presence of some polycrystalline

25

quartz grains with serrated subgrain boundaries indicates minor contribution from a

higher grade metamorphic rock source.

Spatially, detrital compositions of Sindong Group sandstones are generally similar

in all study part (northern, middle, and southern parts), with minor amount of

volcanic lithic fragments occur in the Jinju Formation. In the Nakdong and

Hasandong formations, detritus was largely derived from felsic plutonic rock and

medium to high metamorphic and meta-sedimentary exposed in the source region,

but in the Jinju Formation in the middle and southern parts, volcanic rock

fragments started to occur in the lower sequence, and their abundance is

dramatically increased in upper sequence, suggested that volcanic rocks were

exposed in the middle and southern parts of the basin.

5.2. Provenance from SEM-CL analysis

Comparison of provenance interpretation made on the basis of SEM-CL with that

made on the basis petrographic data. This method reveals that metamorphic rocks

(basement rock) were the most important source rocks for the Sindong Group

sandstones.

In all studied parts, metamorphic quartz was the most dominant quartz type, in

particular the southern part had more metamorphic quartz than the other two parts.

The plutonic quartz content gradually decreases upsection, except for some

formation boundaries.

26

Figure 10. Bar plots showing plutonic, volcanic, and metamorphic quartz grains in the Sindong Group sandstones from the northern part, as determined by SEM-CL analysis.

49.8%

35.0%

34.0%

48.4%

25.9%

29.5%

43.4%

26.0%

25.2%

0.0%

0.5%

0.0%

0.6%

0.2%

0.2%

0.8%

1.1%

1.2%

50.2%

64.6%

66.0%

51.0%

73.8%

70.2%

55.8%

72.9%

73.6%

0% 20% 40% 60% 80% 100%

Lower ND

Middle ND

Upper ND

Lower HSD

Middle HSD

Upper HSD

Lower JJ

Middle JJ

Upper JJ Northern

Part

Plutonic Quartz

Volcanic Quartz

Metamorphic Quartz

27

Figure 11. Bar plots showing plutonic, volcanic, and metamorphic quartz grains in the Sindong Group sandstones from the middle part, as determined by SEM-CL analysis.

41.9%

43.3%

47.2%

35.6%

38.4%

29.0%

46.7%

32.3%

32.4%

1.1%

1.9%

1.8%

2.8%

1.8%

1.9%

3.6%

6.2%

9.3%

57.1%

54.9%

51.0%

61.5%

59.8%

69.1%

49.6%

61.6%

58.3%

0% 20% 40% 60% 80% 100%

Lower ND

Middle ND

Upper ND

Lower HSD

Middle HSD

Upper HSD

Lower JJ

Middle JJ

Upper JJ Middle

Part

Plutonic Quartz

Volcanic Quartz

Metamorphic Quartz

28

Figure 12. Bar plots showing plutonic, volcanic, and metamorphic quartz grains in the the Sindong Group sandstones from the southern part, as determined by SEM-CL analysis.

19.7%

19.1%

21.7%

27.0%

26.2%

25.2%

23.5%

22.7%

21.9%

0.3%

2.2%

0.2%

3.4%

3.3%

3.0%

1.1%

3.9%

24.5%

79.9%

78.7%

78.1%

69.6%

70.5%

71.9%

75.4%

73.4%

38.4%

0% 20% 40% 60% 80% 100%

Lower ND

Middle ND

Upper ND

Lower HSD

Middle HSD

Upper HSD

Lower JJ

Middle JJ

Upper JJ Southern

Part

Plutonic Quartz

Volcanic Quartz

Metamorphic Quartz

29

All formation boundaries in northern part and the boundary between the

Hasandong and Jinju formations showed temporary increase of plutonic quartz.

Such increase in plutonic quartz type suggests that there were small-scale tectonic

events (i.e. uplift) during the transition from one formation to another, and that

such events might have occurred mainly northern part (Fig. 10, 11).

Although minor, the occurrence of volcanic quartz indicates that magmatic

activityoccurred continuously in the source parts. Both the central and southern

parts, volcanic quartz increases with decreasing stratigraphic age, indicate of

increased volcanic activity occurring in the Yeongnam massif during the deposition

of the Sindong Group (Fig 11, 12). Younging of Creataceous detrital zircon U-Pb

age with decreasing stratigraphic age is another piece of evidence supporting

continuous volcanic activity in the source area (Lee et al, 2010).

5.3 Provenance from Zr/Hf ratio of detrital zircon

Zircon of the continental crust is marked by the Zr/Hf ratio of 36-45 and differs

significantly from that of the mantle source having the Zr/Hf ratio of 60-68 (Pupin,

2000). It was also reported that the Zr/Hf ratio of 30-50 in zircon crystallized from

magma originated in the crust (mainly granitoids, Fleischer, 1955; Erlank et al,

1978; Wang et al, 2010), and 54-135 in alkali basalt, nephelinite, and nepheline

syenite (Brooks, 1970; Erlank et al., 1978, Pupin, 2000). Tholeiitic plagiogranite

and hypersolvus alkaline/peralkaline granite/syenite are formed by dry partial

30

melting of the upper depleted mantle, and zircons of these rocks have high Zr/Hf

ratio (>50). Theses rocks are of anorogenic origin. Compared with the large

domain have in Zr/Hf raio occupied by anorogenic rocks, zircons of orogenic,

especially calc-alkaline granitoids had low Zr/Hf ratio (30~50) (Fig. 13).

Detrital zircons in the southern part are composed of 60% orogenic zircon and 40%

anorogenic zircon. Distribution of zircon source rock did not change upsection. In

the middle part, detrital zircons comprise 80% orogenic zircon and 20% anorogenic

zircon. Distributed orogenic zircon source rocks in the middle part were more

widely than in southern part. In the northern part, anorgenic zircon of the Nakdong

Formation was more than 60%, but orogenic/anorgenic zircon ratios in the

Hasandong and Jinju formations were 60:40 and were similar to the zircon ratio in

the middle part (Table. 6). It is interpreted that source rock was consistent in the

southern part during the deposition from the Nakdong to Jinju formations.

The Kolomogorov-Smirnoff statistics further establish the affinity or difference of

the studied samples (Table. 7, Fig. 17). The Nakdong Formation in the northern

part was different from others. The Nakdong Formation in the middle part, the

Nakdong Formation in the southern part, the Hasandong Formtaion in the northern

part and the Hasandong Formation in the southern part have strong linkages.

Probably, the early Sindong Group deposition period might have shared the similar

provenance. But, if their source rocks have had similar felsic granitic rocks, zircons

could have had similar Zr/Hf ratio, considering that felsic granitic rocks have

similar zircon Zr/Hf ratios. So, additional provenance information is needed.

31

Figure 13. Comparison of the Zr/Hf ratios of zircons from different genetic types (crustal -derived or mantle-derived) of granotoids; box plots show the 25% and 75% (limits of the boxes), the median (thin line), the mean (coarse line) and the maximum and minimum values excluding outliers (Puppin, 2002)

Mantle-derived magma source

Crust-derived magma source

Anorogenic magmatic rocks

Orogenic magmatic rocks

32

Figure 14. Histograms and sepctra of Zr/Hf ratio of detrital-zircons of the northern part. Columns are arranged in stratigraphic order with oldest samples at bottom.

0

5

10

15

0 10 20 30 40 50 60 70 80 90 100

Jinju

Fm.

0

5

10

15

20

0 10 20 30 40 50 60 70 80 90 100

Hasandong

Fm.

0

5

10

15

0 10 20 30 40 50 60 70 80 90 100

Nakdong

Fm.

33

Figure 15. Histograms and sepctra of Zr/Hf ratio of detrital-zircons of the middle part. Columns are arranged in stratigraphic order with oldest samples at bottom.

0

5

10

15

20

0 10 20 30 40 50 60 70 80 90 100

Jinju

Fm.

0

2

4

6

8

10

0 10 20 30 40 50 60 70 80 90 100

Hasandong

Fm.

0

4

8

12

16

0 10 20 30 40 50 60 70 80 90 100

Nakdong

Fm.

34

Figure 16. Histograms and sepctra of Zr/Hf ratio of detrital-zircons of the southern part. Columns are arranged in stratigraphic order with oldest samples at bottom.

0

2

4

6

8

0 10 20 30 40 50 60 70 80 90 100

Jinju

Fm.

0

2

4

6

8

0 10 20 30 40 50 60 70 80 90 100

Hasandong

Fm.

0

2

4

6

8

0 10 20 30 40 50 60 70 80 90 100

Nakdong

Fm.

35

Figure 17. Linkage of each formation by K-S test (p≥0.05) of detrital zircon Zr/Hf ratio for the Sindong Group samples.

36

5.4 Probable sources

Previous studies on paleocurrent indicated that Sindong Group sediments were

supplied from north, northwest, and west (138°±71°/ Chang & Kim, 1968; Koh

1986). In the Cretaceous, the Okcheon Fold Belt and Yeongnam Massif might have

been provenance influenced by Jurassic Daebo Orogeny.

The SEM-CL study indicates that there were three main sources of quartz for the

Sindong Group sandstones: metamorphic rocks, plutonic rocks, and volcanic

materials. The most likely metamorphic source rocks are are: (1) Precambrian

granite-gneiss basement, (2) Paleozoic meta-sediment cover rocks and, (3) foliated

Triassic granitic rocks (Fig. 1(B)). The Precambrian basement and the Cretaceous

sedimentary sequence were separated by unconformity. The litologies of

Precambrian in age exposed in the Yeongnam Massif include various kinds of

granitic gneiss and lesser amount of amphibolite (Song, 1989). These rocks are

medium-high metamorphic rocks, and mainly metamorphosed peraluminous S-type

granitoid or calc-alkaline igneous rock (Song, 1989; Lee et al, 1986; 2001; Kang et

al, 2008). Paleozoic metasedimentary rocks in the Okcheon belt consist of quartzite,

quartz schist, mica schist, garnet-biotite schist and phyllite metamorphosed by

several orogeny events, the middle Paleozoic Orogeny to Jurassic Orogeny (Kim et

al., 1995; Kim et al., 2003). Foliated Triassic granites were distributed locally, and

were metamorphosed lowly by Jurassic Daebo Orogeny. Among the Triassic

igneous rock, Daegang and Hamchang granites, and Schaeong syenite are post-

37

orogenic or anorogenic granitoids (A-type granite) that seems responsible sources

of anorogenic zircons (Zr/Hf >50) in the Sindong Group sandstone.

Quartz of plutonic origin contributes 20~40% of the total quartz in all of quartz-

rich sandstones analyzed in this study. The closet granitic rocks seem to be the

Jurassic granites widely distributed in the Yeongnam Massif. These Jurassic

granites are orogenic magmatic arc granite having zircon Zr/Hf ratios around

30~50.

Volcanic quartz shows an increasing trend from the Hasandong Formation to the

Jinju Formation; significantly the upper Jinju Formation had a large portion of

volcanic detritus in the middle and southern parts. The presence of volcanic quartz

and volcanic rock fragments in the Sindong Group sandstones indicates that these

sediments were supplied from syn-depositional volcanism. In the middle and

southern parts of the Gyeongsang Basin, the Hasandong Formation deposition

might have started with minor contemporaneous volcanism in the provenance,

whereas the upper Jinju Formation deposition started more active volcanism.

5.5 Spatial and temporal source rock changes

Combined sandstone petrography, SEM-CL analysis of detrital quartzs, and the

Zr/Hf ratio of detrital zircons suggest that there were spatial and temporal source

rock changes during Sindong Group deposition.

The presence of anorogenic magmatic zircon in the Nakdong Formation in the

38

northern part suggests different source rock distribution in source area. The

overlying two formations in the northern part have anorogenic zircons below 20%,

but the Nakdong Formation had over 60% of anorogenic zircon. Anorogenic

zircons might have been derived from Triassic igneous rocks that are distributed in

very narrow part (Hamchang granite). Thus, in the northern part, Triassic rocks

were exhumed fast during the Nakdong Formation deposition period.

Samples of the Hasandong and Jinju formations of the northern part comprise the

mainly continental basement setting and Jurassic batholith. The Zr/Hf ratio of

zircon grains were below 50, which indicates that these zircon grains were derived

from orogenic magmas evolved from crustal materials.

The Nakdong Formation in the middle part and the Hasandong Formation in the

north part and in the southern part are very similar. This result suggests that the

Nakdong and Hasandong Formation might have shared similar drainage networks,

and axial paleocurrent flow could have existed. Additional paleocurrent study is

needed to prove this hypothesis.

In the southern part, three formations of the Sindong Group have strongly similar

provenance characteristics. Although the Hasandong Formation was influenced by

the provenance of the middle part, as ever the Sindong Group sandstone in the

southern part might have different source area.

Temporal change in source rocks does not have wide variance except upper Jinju

Formation. Although plutonic quartz content gradually decreased upsection, range

of decreasing variance was only 10%. Generally, source rock of Sindong Group

39

sandstone were mainly Precambrian granitic-gneiss basement and Jurassic Daebo

Orogenic granitic rock, while minor source rocks were Triassic granitic rocks and

syn-depositional volcanic rocks.

40

6. Conclusions

The Gyeongsang Basin was developed in the eastern continental margin of Asia

during Early Cretaceous time when strike-slip movement dominated the margin

(Chun and Chough, 1992; Okada and Sakai, 1993). Deposition of the Sindong

Group was limited to the NNE-SSW trending Nakdong Trough located in the

western part of the present Gyeongsang Basin (Chang, 1985, 1987) which is

covered by the Hayang Group.

Provenance of the Cretaceous Sindong Group sandstones was investigated using

sandstone petrography, monochromatic SEM-CL analysis of detrital quartz grains

and Zr/Hf ratio of detrital zircon grains.

Twenty seven sandstone samples from the Sindong Group, from three different

parts of the Sindong Group distribution part (northern, middle, and southern parts),

were analyzed by sandstone petrography and quartz SEM-CL analysis. Sandstone

petrography suggests that provenance is transitional continental block and source

rocks are mainly medium-grade metamorphic rocks.

The SEM-CL analysis reveals that 38~80% of the quartz grains in all studied

samples were derived from metamorphic rocks, 19~50% from plutonic rocks, and

0~24% from volcanic rocks. Accordingly, major source rocks were metamorphic

rocks, followed by granitic rocks, and notable amounts of quartz were also derived

from volcanic rocks.

The Zr/Hf ratio of zircon grains suggests that detrital zircons were mainly derived

41

from orogenic I-type or S-type granite (i.e., Precambrian granitic-gneiss, and

Jurassic batholith granite) originated in the continental crust, but zircon grains of

the Nakdong Formation in the northern part were derived from post-orogenic or

anorogenic A-type granite (i.e., Triassic igneous rock).

Temporal source-rock changes did not have wide variance except the upper Jinju

Formation. A decreasing trend (<10%) of plutonic source upsections in each

formation of northern and middle parts may suggest gradual expansion of drainage

area.

Spatial variances of the Sindong Group sandstones are not much. The Singdong

Group sediments were mainly derived from the northern and wertern source, most

probably located on the Yeongnam Massif. The Yeongnam massif did not have

different source rocks spatially, and linkage of drainages of strata in different parts

was interrelated. And, the strong provenance relationship among the Hasandong

Formation in the northern part, the Nakdong Formation in the middle part, and the

Hasandong Formation in the southern part may suggest former existence of axial

flow during the Hasandong Formation deposition period, but detailed paleocurrent

study is necessary to prove this relationship.

42

REFERENCES

Augustsson C., Rusing T., Adams J.C., Chmiel H.,Kocabayoglu M., Buld M.,

Zimmermann U., Berndt J., and Kooijman E., 2011, Detrital quartz and

zircon combined: the production of mature sand with short transportation

paths along the Cambrian West Gondwana margin, northwestern Argentina,

Journal of Sedimentary Research, 81, 284-298.

Basu A., 1985, Influence of climate and relief on compositions of sand released at

source parts, in Zuffa, G.G. (ed.), Provenance of Arenites: NATO, ASI

Series, Series C, Mathematical and Physical Science, 148, 1–18.

Basu A., Young S.W., Suttner L.J., James W.C., and Mack G.H., 1975, Re-

evaluation of the use of undulatory extinction and polycrystallinity in detrital

quartz for provenance interpretation. Journal of Sedimentary Research, 45,

873-882.

Bassett K., Franz E., and Bernet M., 2006, Provenance analysis of the Paparoa and

Brunner Coal Measures using integrated SEM-cathodoluminescence and

optical microscopy, New Zealand Journal of Geology and Geophysics, 49,

241-254.

Bernet M., and Bassett K.N., 2005, Single quartz grain SEM-CL/optical

microscopy provenance analysis, Journal of Sedimentary Research, 75, 492-

500.

Bernet M., Kapoutsos D., and Bassett K.N., 2007, Diagenesis and provenance of

43

Silurian quartz arenites in south-eastern New York State, Sedimentary

Geology, 201, 43-55

Blatt H., 1982, Sedimentary petrology, San Francisco, USA, WH Freeman and

Company, 564 p.

Boggs S. Jr., Kwon Y.I., Goles G.G., Rusk B.G., Krinsley D., and Seyedolali A.,

2002, Is quartz cathodoluminescence color a reliable provenance analysis

tool? A quantitative examination, Journal of Sedimentary Research, 72, 408-

415.

Brooks C.K., 1970, The concentrations of zirconium and hafnium in some igneous

and metamorphic rocks and minerals, Geochimica et Cosmochimica Acta, 34,

411-416.

Chang K.H., 1968, An introduction to the stratigraphy of Gyeongsang Group,

Gyeongsang Province, South Korea, Journal of the Geological Society of

Korea, 4, 41-44 (in Korean).

Chang K.H., 1970, Geology of Upper Mesozoic strata, N. Gyeongsang Province,

southern Korea(1), Journal of the Geological Society of Korea, 6, 1–12 (in

Korean).

Chang K.H., 1975, Cretaceous stratigraphy of Southeast Korea, Journal of the

Geological Society of Korea, 11, 1–23.

Chang K.H., 1988, Cretaceous stratigraphy and paleocurrent analysis of

Kyongsang Basin, Korea, Journal of the Society of Korea, 24, 194-205.

Chang K.H., 2002. A review on the stratigraphy and recent researches of the

44

Cretaceous Gyeongsang Basin, Korea. In Jin M.S., Lee S.R., and Choi H.I.

(eds.), Mesozoic Sedimentation, Igneous Activity and Mineralization in

South Korea, Daejeon, Korea Institute of Geoscience and Mineral Resources,

1-9.

Chang K.H. and Kim H.M., 1968, Cretaceous paleocurrent and sedimentation in

northwestern part of Kyongsang basin, southern Korea, Journal of the

Geological Society of Korea, 4, 77–97.

Choi D.K., 1985, Spores and pollen from the Gyeongsang SuperGroup,

southeastern Korea and their chronologic and paleoecologic implications,

Journal of the Paleontological Society of Korea, 1, 33–50.

Choi D.K. and Park J.B., 1987, Palynology of the Jinju Formation (Lower

Cretaceous), Waegwan-Daegu and Jinju parts, Korea, Journal of the

Paleontological Society of Korea, 1, 28–43.

Choi H.I., 1981, Depositional environments of the Sindong Group in the

southwestern part of the Kyeongsang Basin, Unpublished PhD thesis, Seoul

National University, 144 p.

Choi H.I., 1986a, Fluvial plain/lacustrine facies transition in the Cretaceous

Sindong Group, south coast of Korea, Sedimentary Geology, 48, 295–320.

Choi H.I. 1986b. Sandstone petrology of the Sindong Group, southwestern part of

the Gyeongsang Basin, Journal of the Geological Society of Korea, 22, 212–

223.

Choi S.J., 1987. Study on the Lower Cretaceous charophytes from the Upper

45

Gyeongsang SuperGroup, Journal of the Paleontological Society of Korea, 3,

79–92.

Choi S.J., 1989. Fossil charophytes from the Nakdong Formation in Seonsangun,

Gyeongsangbukdo, Korea, Journal of the Paleontological Society of Korea, 5,

28–38.

D'Lemos R.S., Kearsley A.T., Pembroke J.W., Watt G.R., and Wright P., 1997,

Complex quartz growth histories in granite revealed by scanning

cathodoluminescence techniques, Geological Magazine, 134, 549-552.

Dickinson W.R., 1970, Interpreting detrital modes of graywacke and arkose,

Journal of Sedimentary Petrology, 40, 695–707.

Dickinson W.R., and Suczek C.A., 1979, Plate tectonics and sandstone

compositions, American Association of Petroleum Geologists, Bulletin, 63,

2164–2182.

Dickson W.R., Beard L.S., Brakenridge G.R., Erjavec J.L., Ferguson R.C., Inman

K.F., Knepp R.A., Lindberg F.A., and Ryberg P.T., 1983, Provenance of

North America Phanerozoic sandstones in relation to tectonic setting,

Geological Society of America Bulletin, 94, 222-235.

Doh S.J., Hwang C.S. and Kim K.H., 1994, A paleomagnetic study of sedimentary

rocks from Kyeongsang SuperGroup in Milyang Sub-basin. Journal of the

Geological Society of Korea, 30, 211–28 (in Korean with English abstract).

Egawa K., Cheong D., Otoh S., Strictiral and provenance analyses of a newly

defined major fault: the Homyeong Fault as a northern boundary fault of the

46

Cretaceous Nakdong Trough, South Korea, Geosciences Journal, 10, 249-

262.

Erlank A.J., Smith H.S., Marchant J.W., Cardoso M.P., and Ahrens L.H., 1978,

Hafnium, In Wedepohl K.H. (ed.), Handbook of Geochemistry, Berlin,

Springer Verlag, 72.

Gonzalez-Acebron L., Arribas J., Mas R., 2007, Provenance of fluvial sandsones at

the start of late Jurassic-Early Cretaceous rifting in the Cameros Basin (M.

Spain), Sedimentary Geology, 202, 138-157.

Gotte T., and Richter D.K., 2006, Cathodoluminescence charcterization of quartz

particles in mature arenites, Sedimentology, 53, 1347–1359.

Gotze J., Plotze M., and Habermann D., 2001, Origin, spectral characteristics and

practical applications of the cathodoluminescence (CL) of quartz—a review,

Mineralogy and Petrology, 71, 225–250.

Hwang B.H., Son M., Yang K., Yoon J. and Ernst W.G., 2008, Tectonic evolution

of the Gyeongsang Basin, southeastern Korea from 140 Ma to the present,

based on a strike-slip and block rotation tectonic model, International

Geology Review, 50, 343–363.

Heaman L., Bowuns R., and Crocket J., 1990, The chemical composition of

igneous zircon suites: Implications for geochemical tracer studies, Gmhimica

et Cosmochimica Acfa, 54, 1597-1607.

Hoskin P.W.O., 2003, The composition of zircon and igneous and metamorphic

petrogenesis, Reviews in Mineralogy and Geochemistry, 53, 27-62.

47

Hoskin P.W.O. and Ireland T., 2000, Rare earth element chemistry of zircon and its

use as provenance indicator, Geology, 28, 627-630.

Hwang B.H., Son M., Yang K.H., Yoon J.H., and Ernst W.G., 2008, Tectonic

evolution of the Gyeongsang Basin, southeastern Korea from 140 Ma to the

present, based on a strike-slip and block rotation tectonic model,

International Geology Review, 50, 343-363.

Jwa Y.J., 2008, A preliminary study on granite suite and supersuite for the Jurassic

granites in South Korea, Journal of Petrological Society of Korea, 17, 222-

230 (in Korean with English abstract).

Jwa Y.J., Kim J.S., Kim K.K., 2005, Granite suite and supersuite for the Triassic

granites in South Korea, Journal of Petrological Society of Korea, 14, 226-

236230 (in Korean with English abstract).

Jwa Y.J., Lee Y.I. and Orihashi Y., 2009, Eruption age of the Kusandong Tuff in

the Cretaceous Gyeongsang Basin, Korea, Geosciences Journal, 13, 265–73.

Jwa Y.J., Orihashi Y., Kim H.G. and Sung K.H., 2008, Zircon U-Pb ages of the

Mesozoic granites in the central Yeongnam massif: Including newly found

Cretaceous granites. 2008, Joint Geological Sciences Meeting Abstracts

volume, 14.

Kanaori Y., 1986, A SEM cathodoluminescence study of quartz in midly deformed

granite from the region of the Atotsugawa Fault, Central Japan,

Tectonophysics, 131, 133-146.

Kim C.S., Park K.H., and Paik I.S., 2005, 40Ar/39Ar age of the volcanic pebbles

48

within the Silla Conglomerate and the deposition timing of the Hayang

Group. Journal of the Petrological Society of Korea, 14, 38–44 (in Korean

with English abstract).

Kim J.H. 1996. Mesozoic tectonics in Korea, Journal of Southeast Asian Earth

Sciences 13, 251–265.

Kim S.W., Oh C.W., Choi S.G., Ryu I.C., and Itaya T., 2010, Ridge subduction-

related Jurassic plutonism in and around the Okcheon Metamorphic Belt,

South Korea, and implications for Northeast Asian tectonics, International

geology review, 47, 248-269.

Kim Y.J., Cho D.L., and Lee C.S., 1998, Petrology, geochemistry and tectonic

implication of the A-type Daegang granite in the Namwon part, southwestern

part of the Korean Peninsula, Journal of Economical and Environmental

Geology of Korea, 1998, 399-413 (in Korean with English abstract).

Kim Y.J., Lee C.S., and Kang S.W., 1991, Petrochemistry on intermediated basic

plutons in Jirisan part of the Ryongnam Massif, Journal of Korean Earth

Science Society, 12, 100-122

Kobayashi T., and Suzuki K., 1936, Non-marine shells of the Nakdong-Wakino

Series, Japan Journal of Geology and Geography, 13, 243–57.

Koh I.S., 1974, Sedimentary petrology of Nakdong Group (1), Journal of the

Geological Society of Korea, 10, 207–224 (in Korean).

Koh I.S., 1986, Study on the source rocks of the Nakdong Group. Journal of the

Geological Society of Korea, 22, 233–256 (in Korean with English abstract).

49

Koh I.S., 1989, Sandstone diagenesis of the Nakdong Group, Journal of the

Geological Society of Korea, 25, 381–391 (in Korean with English abstract).

Koh I.S. and Lee Y.G, 1972, Sedimentary Petrology of the Nakdong Group in

Jinju-Namhae Part, Gyeongsangnam-do, Korea, Journal of the Geological

society of Korea, 8, 93-122.

Kwon Y.I., and Boggs S. Jr., 2002, Provenance interpretation of Tertiary

sandstones from the Cheju Basin (NE East China Sea): a comparison of

conventional petrographic and scanning cathodoluminescence techniques,

Sedimentary Geology, 152, 29-43.

Lee C.H., Lee S.W., Ock S.S., and Song Y.S., Petrology of the blastoporphyritic

granite gneiss in the southwestern part of the Sobaegsan Massif, Journal of

Korean Earth Science Society, 22, 528-547 (in Korean with English abstract).

Lee D.W., 1999, Strike-slip fault tectonics and basin formation during the

Cretaceous in the Korean Peninsula, Island Arc, 8, 218–231.

Lee J.I., and Lee Y.I., 2000, Provenance of the Lower Cretaceous Hayang Group,

Gyeongsang Basin, southeastern Korea: Implications for continental-arc

volcanism, Journal of Sedimentary Research, 70, 151–158.

Lee T.H., Park K.H., Chun J.H., and Yi K.W., 2010, SHRIMP U-Pb Zircon Ages

of the Jinju Formation and Silla Conglomerate, Gyeongsang Basin, Journal

of Petrological Society of Korea, 19, 89-101 (in Korean with English

abstract).

Lee Y.I., 1999, Stable isotopic composition of calcic soils of the Early Cretaceous

50

Hasandong Formation, southeastern Korea, Palaeogeography,

Palaeoclimatology, Palaeoecology, 150, 123–133.

Lee Y.I., and Lim D.H., 2008, Sandstone diagenesis of the Lower Cretaceous

Sindong Group, Gyeongsang Basin, southeastern Korea: Implications for

compositional and paleoenvironmental controls, Island Arc, 17, 152–171.

Lee Y.I., Choi T., Lim H.S., and Orihashi Y., 2010, Detrital zircon geochronology

of the Cretaceous Sindong Group, Southeast Korea: Implications for

depositional age and Early Cretaceous igneous activity. Island Arc, 19, 647-

58.

Linnen R., and Keppler H., 2002, Melt composition control of Zr/Hf fractionation

in magmatic processes, Geochimica et Cosmochimica Acta, 66, 3293-3301.

Milliken K.L., Laubach S.E., 2000. Brittle deformation of sandstone diagenesis as

revealed by scanning cathodoluminescence imaging with application to

characterisation of fractured reservoirs. In: Pagel M., Barbin V., Blanc P.,

and Ohnenstetter D. (eds.) Cathodoluminescence in geoscience, Berlin,

Springer Verlag, 225-243.

Noh J.H., and Choi W.I., 2001, Diagenesis and diagenetic mineral facies of

sandstones from the Sindong Group in Gunwi part, Journal of the Geological

Society of Korea, 37, 323-344 in Korean with English abstract).

Noh J.H. and Park H.S., 1990, Mineral diagenesis of sandstones of the Kyongsang

SuperGroup in Goryeong part, Journal of the Geological Society of Korea,

26, 371–392.

51

Okada H., 1999, Plume-related sedimentary basins in East Asia during the

Cretaceous, Palaeogeography, Palaeoclimatolology, Palaeoecolology 150, 1–

11.

Okada H., 2000, Nature and development of Cretaceous sedimentary basins in East

Asia: A review, Geosciences Journal, 4, 271–282.

Otoh S. and Yanai S., 1996, Mesozoic inverse wrench tectonics in Far East Asia:

Examples from Korea and Japan, In Yin A. and Harrison T.M. (eds.) The

Tectonic Evolution of Asia, New York, Cambridge University Press, New

York, 401–419.

Owen M., 1987, Hafnium content of detrital zircons, a new tool for provenance

study, Journal of Sedimentary Petrology, 57, 824-830.

Park K.H., Kim D.H., Song Y.S., and Cheong C.S., 2006, Rb-Sr isotopic

composition of Mesozoic Sancheong Syenite and its geological implication,

Journal of Petrological Society of Korea, 15, 1-9 (in Korean with English

abstract).

Park K.H., Lee H.S., Song Y.S., and Cheong C.S., 2006, Sphene U-Pb ages of the

granite-granodiorites fron Hamyang, Geochang and Yeongju parts of the

Yeongnam Massif, Journal of Petrological Society of Korea, 15, 39-48 (in

Korean with English abstract).

Park K.H., Song Y.S., Park M.E., Lee S.G., and Ryu H.J., 2000, Petrological,

geochemical and geochronological studies of Precamvrian basement in the

Northeast Asia region: 1. age of the metamorphism of Jirisan part, Journal of

52

Petrological Society of Korea, 9, 29-39 (in Korean with English abstract).

Park T.H., Iwamori H., Orihashi Y., Jwa Y.J. and Kwon S.T. 2008, Zircon U-Pb

age from Cretaceous to Paleogene granitic rocks, South Korea – SW Japan:

Constraints on the spatiotemporal evolution of the granitic magmatism,

Proceedings of the Annual Joint Conference of the Petrological Society of

Korea and Mineralogical Society of Korea, 23–25.

Pupin J.P., 2000, Granite genesis related to geodynamics from Hf-Y in zircon,

Traction of the Royal Society of Edinburgh: Earth Sciences, 91 245-256.

Sagong H., Kwon S.T., and Ree J.H., 2005, Mesozoic episodic magmatism in

South Korea and its tectonic implication, Tectonics, 24, 1-18.

Seyedolali A., Krinsley D.H., Boggs S. Jr., O'Hara P.F., Dypvik H., and Goles

G.G., 1997, Provenance interpretation of quartz by scanning electron

microscope-cathodoluminescence fabric analysis, Geology, 25, 787-790.

Song Y.S., 1989, Geochemistry of the Precambrian metamorphic rocks from the

central Sobaegsan Massif, Korea, Journal of the Korean Institute of Mining

Geology, 22, 293-300 (in Korean with English abstract).

Song Y.S., and Lee S.M., 1989, Petrology of the Precambrian metamorphic rocks

from the central Sobaegsan Massif, Korea, Journal of the Geological Society

of Korea, 25, 451-468.

Suttner L.J., Basu A., and Mack G.H., 1981, Climate and the origin of quartz

arenites, Journal of Sedimentary Petrology, 51, 1235–1246.

Taira A., 2001, Tectonic evolution of the Japanese Island arc system. Annual

53

Review of Earth and Planetary Sciences, 29, 109–134.

Tortosa A., Palomares M. and Arribas J., 1991. Quartz grain types in Holocene

deposits from the Spanish Central System: some problems in provenance

analysis, In: Morton A.C., Todd S.P. and Haughton P.D.W. (eds),

Developments in Sedimentary Provenance Studies, Geological Society of

London, Special Publication, 157, 47–54.

Yang S., 1989, On the genus Plicatounio (Cretaceous non-marine bivalvia) from

Korea. Transactions and Proceedings of Palaeontological Society of Japan,

News Series, 154, 77–95.

Young S., 1976, Petrographic textures of detrital polycrystalline quartz as an aid in

interpreting crystalline source rocks, Journal of Sedimentary Petrology, 46,

595-603.

Wang X., Griffin W.L., and Chen J., 2010, Hf contents and Zr/Hf ratios in granitic

zircons, Geochemical Journal, 44, 65-72

Weltje G.J., 2006, Ternary sandstone composition and provenance: an evaluation of

the ‘‘Dickinson model’’, in Buccianti A., Mateu-Figueras G., and

Pawlowsky-Glahn V., (eds), Compositional Data Analysis in the Geosciences:

From Theory to Practice: Geological Society of London, Special Publication

264, 79–99.

Zinkernagel U., 1978, Cathodoluminescence of quartz and its application to

sandstone petrology, Contributions to Sedimentology, 8, 1–69.

54

Table 1. Sample location of the Sindong group sandstone in Gyeongsang Basin

Sample Latitude Longitude Decription

Lower Cretaceous

Sindong Group (Northern part)

H0706-3 36°13'31.48"N 128°25'37.64"E Nakdong Fm. Lower part. Coarse sandstone H0705-5 36°10'58.79"N 128°29'13.85"E Nakdong Fm. Middle part. Coarse Sandstone 0107-4 36°11'1.20"N 128°31'29.11"E Nakdong Fm. Upper part. Medium Sandstone

H0707-2 36°10'43.42"N 128°32'22.23"E Hasandong Fm. Lower part. Coarse Sandstone

0107-7 36°11'18.29"N 128°33'34.77"E Hasandong Fm. Middle part. Medium Sandstone

H0707-5 36°11'2.16"N 128°35'25.12"E Hasandong Fm. Upper part. Coarse Sandstone H0707-14 36°15'22.33"N 128°36'10.67"E Jinju Fm. Lower part. Coarse Sandstone

630-9 36°14'42.35"N 128°37'9.43"E Jinju Fm. Middle part. Coarse Sandstone 0107-9 36°11'3.60"N 128°38'7.52"E Jinju Fm. Upper part. Medium Sandstone

Lower Cretaceous

Sindong Group (Central part)

0722-3 35°40'38.40"N 128°12'16.20"E Nakdong Fm. Lower part. Medium sandstone 0113-12 35°40'37.20"N 128°13'36.60"E Nakdong Fm. Middle part. Medium sandstone 0722-6 35°39'12.00"N 128°12'25.80"E Nakdong Fm. Upper part. Coarse sandstone 0722-7 35°39'13.20"N 128°13'12.00"E Hasandong Fm. Lower part. Fine sandstone 0722-8 35°38'54.00"N 128°13'13.80"E Hasandong Fm. Middle part. Fine sandstone 0722-11 35°37'24.00"N 128°13'44.40"E Hasandong Fm. Upper part. Fine sandstone 0113-5 35°37'38.40"N 128°14'57.60"E Jinju Fm. Lower part. Fine sandstone

072506-1 35°39'2.10"N 128°17'9.20"E Jinju Fm. Middle part. Medium sandstone 0722-16 35°34'34.24"N 128°17'55.50"E Jinju Fm. Upper part. Medium sandstone

55

Table 1. (continued)

Sample Latitude Longitude Decription Lower

Cretaceous Sindong Group (Southern part)

ND-3 35°18'56.40"N 127°58'25.80"E Nakdong Fm. Lower part. Coarse sandstone ND-5 35°17'55.20"N 127°58'52.80"E Nakdong Fm. Middle part. Medium

sandstone 0707-4 35°18'50.00"N 127°59'36.00"E Nakdong Fm. Upper part. Medium sandstone 0106-1 35°18'51.00"N 128° 1'0.60"E Hasandong Fm. Lower part. Medium

sandstone 0703-10 35°18'42.00"N 128° 3'7.40"E Hasandong Fm. Middle part. Fine sandstone 0106-3 35°18'45.09"N 128° 4'0.03"E Hasandong Fm. Upper part. Medium

sandstone 0704-4 35°19'13.00"N 128° 5'21.00"E Jinju Fm. Lower part. Medium sandstone 0106-8 35°17'38.40"N 128° 7'58.80"E Jinju Fm. Middle part. Medium sandstone 0106-11 35°17'0.60"N 128°10'45.00"E Jinju Fm. Upper part. Medium sandstone

56

Table 2. Description of SEM-CL characteristics and features. (modified after Bernet and Bassett, 2005) Features Description Quartz type Percentage Comment

Primary Formed during crystallization and/or cooling aftercrystallization

Zoning

Concentric zoning more common than nonconcentric; can be relatively broad or

narrowly spaced, oscillatory or non-oscillatory, no intra-sample variation in the

type of zoning

Volcanic quartz Plutonic quartz

Vein quartz

~50% <5% <5%

Very common in volcanic quartz, rare in plutonic and vein quartz; indicative of crystal

growth out of an evolving magma or fluid

Randomly oriented microcracks or healed cracks

Relatively thin (<10 mm), dark gray or black lines, sometimes resemble spider webs

Plutonic quartz Vein quartz

100% <1%

Cooling related randomly oriented microcracks and healed fractures have been

observed in all plutonic quartz. They were not observed in volcanic quartz and are very rare

in vein quartz

Homogeneous CL No variation in CL response throughout the grain, CL light gray to dark gray or black

Volcanic quartz Recrystallized quartz ~30% Relatively common in volcanic quartz

Secondary Formed during deformation and/or recrystallization

Grain shattering Brittle deformation in sediment during compaction

Possible for any quartz type Depending on strength of compaction and

matrix content.

Microfractures with preferred orientation

Similar to primary microcracks, but are parallel aligned, several sets possible

Possible for any quartz type

100% in all brittle deformed quartz

Typical in quartz that experienced brittle deformation. Tectonically induced micro-

fractures can also be healed.

Deformation lamellae

Very thin, parallel, closely spaced, dark gray lines, several sets possible

Possible for any quartz type, depending on deformation history

100% in all ductile deformed quartz

Typical feature in quartz that experienced weak ductile deformation (e.g., quartz with

low-grade metamorphic overprint)

Inhomogeneous patchy or

mottled CL

Commonly very dark CL with irregular, somewhat lighter CL in some areas

Low- to medium-grade metamorphic quartz

Variable, depending on degree of

metamorphism

Typical for quartz with strong undulose extinction, subgrain boundaries and first

mosaics of recrystallized quartz. Mottled CL in high-grade metamorphic quartz has been

described by Seyedolali et al. (1997).

Homogeneous CL Black CL response, nothing else visible

Recrystallized quartz including most vein

quartz and high-grade metamorphic quartz

90% of all recrystallized quartz

Very typical for strongly or completely recrystallized quartz in medium- to high-grade metamorphic rocks and in recrystallized vein

quartz

57

Table 3. Quartz types identified by their SEM-CL characteristics and features. (Modified after Bernet and Bassett, 2005)

Quartz type SEM-CL features comment Quartz type SEM-CL features comment

Plutonic quartz

- light gray CL - microcracks and healed cracks (randomly oriented) - rare zoning

May contain fluid-inclusion trains and mineral inclusion

Very low-grade metamorphic quartz

(brittle deformed quartz)

- microfractures or healed fractures with preferred orientation

Tectonically induced. Several generations are possible in the

same grain.

Volcanic quartz

- light gray to black CL

- homogeneous CL or patchy CL

- common zoning - large open cracks

Inclusions and open cracks can be seen

Cracks formed during rapid cooling

Low to medium-grade metamorphic

quartz (ductile deformed

quartz)

- deformation lamellae

- complex shear Tectonically induced.

Recycled detrital quartz

- grain shattering (against grain

contact = diagenetic)

Grains look as though if they experienced pressure solution

Low to medium-grade metamorphic

quartz (partial recrystallized

quartz)

- gray to black CL - patchy or mottled CL

Quartz grains that experienced metamorphic

overprint.

High-grade metamorphic quartz

- black CL - homogeneous CL

Easy to identify with the optical microscope

(polycrystalline).

58

Table 4. Point count data from the Sindong Group sandstones.

Formation Sample Rock type

Qp, 2-3 (%)

Qp, >3 (%)

Qnu (%)

Qu (%)

Qtot (%)

P (%)

K (%)

Ftot (%)

Lm (%)

Lv (%)

Ls (%)

Ltot (%)

Northern Area Lower ND 0706-3(H) cs 1.0 12.7 17.7 34.4 65.8 10.3 7.6 17.9 11.7 - 4.7 16.3 Middle ND 0705-5(H) ms 4.3 7.3 27.7 27.7 67.0 18.7 6.3 25.0 6.3 - 1.7 8.0 Upper ND 0107-4 ms 2.7 10.0 27.7 23.0 63.3 19.3 12.0 31.3 5.3 - - 5.3

Lower HSD 0707-2(H) ms 6.3 13.0 19.3 23.0 61.7 20.0 7.3 27.3 11.0 - - 11.0 Middle HSD 0107-6 ms 2.3 5.0 7.7 25.7 63.0 17.3 10.7 28.0 6.7 - 2.3 9.0 Middle HSD 0107-7 ms 3.3 17.7 21.0 23.3 56.0 22.3 15.0 37.3 6.7 - - 6.7 Upper HSD 0707-5(H) ms 6.3 6.3 12.7 18.0 56.7 21.7 11.0 32.7 9.0 - 1.7 10.7 Lower JJ 0707-14(H) ms 5.3 16.7 22.0 18.0 58.0 19.0 14.7 33.7 6.3 - 2.0 8.3 Middle JJ 630-9 cs 4.0 8.3 12.3 21.7 44.7 27.3 19.0 46.3 7.3 0.7 1.0 9.0 Middle JJ 0107-10 fs 4.3 4.3 8.7 21.7 69.3 21.7 8.0 29.7 1.0 - - 1.0 Upper JJ 0107-9 fs 4.7 8.3 13.0 35.0 69.7 21.7 5.7 27.3 3.0 - - 3.0

Middle Area Lower ND 0722-3 ms 4.7 7.3 35.7 34.7 82.3 10.3 1.0 11.3 4.7 - 1.7 6.3 Middle ND 0113-12 fs 5.7 9.0 29.7 38.3 82.7 8.7 4.3 13.0 4.0 - 0.3 4.3 Upper ND 0722-6 ms 2.0 4.7 30.3 36.0 73.0 16.0 8.3 24.3 2.7 - - 2.7

Middle HSD 0722-8 fs 1.7 2.7 35.3 32.7 72.3 17.3 8.7 26.0 1.7 - - 1.7 Upper HSD 0722-11 fs 0.7 5.0 22.0 42.3 70.0 15.3 7.3 22.7 6.7 0.7 - 7.3 Lower JJ 0113-5 fs 1.7 3.3 18.3 30.0 53.3 21.7 14.3 36.0 4.0 6.7 - 10.7 Middle JJ 072506-1 ms 3.3 5.7 20.7 26.3 56.0 21.7 13.7 35.3 3.0 3.3 2.3 8.7 Upper JJ 0113-1 fs 0.7 11.0 19.0 26.3 57.0 18.3 13.3 31.7 3.3 6.3 1.7 11.3

Table 4. (continued)

59

Southern Area Lower ND ND-3 ccs 8.0 24.7 17.3 30.3 80.3 4.0 0.7 4.7 10.3 - 4.7 15.0 Middle ND ND-5 cs 2.0 7.3 39.7 27.0 76.0 12.0 3.7 15.7 3.7 - 4.7 8.3 Upper ND 0707-4 cs 3.7 4.3 33.3 27.3 68.7 11.3 8.0 19.3 8.7 - 3.3 12.0

Lower HSD 0106-1(1) ms 6.3 4.7 29.3 38.7 79.0 8.3 5.3 13.7 3.3 - 4.0 7.3 Lower HSD 0106-1(2) fs 3.3 5.7 34.7 36.0 79.7 9.7 3.7 13.3 4.3 - 2.7 7.0 Middle HSD 0106-2 fs 1.7 9.3 27.0 29.3 67.3 17.7 1.7 19.3 6.3 - 7.0 13.3 Middle HSD 0703-10 ms 4.0 6.7 24.7 25.7 61.0 23.0 10.0 33.0 1.3 2.7 2.0 6.0 Upper HSD 0106-3 fs 3.3 4.7 29.0 30.0 67.0 19.7 8.0 27.7 2.0 1.3 2.0 5.3 Upper HSD 0117-1-13 ms 3.3 5.0 19.0 34.3 61.7 26.0 7.0 33.0 1.3 0.7 3.3 5.3 Lower JJ 0117-2-D1 ms 4.7 7.7 27.0 18.7 58.0 19.3 9.3 28.7 4.0 6.3 3.0 13.3 Middle JJ 0106-8 fs 4.3 5.7 30.7 22.0 62.7 22.0 6.3 28.3 1.3 5.7 2.0 9.0 Upper JJ 0106-11 ms 0.7 5.7 14.3 27.0 47.7 12.3 13.3 25.7 0.7 20.7 5.3 26.7

Qp, 2-3 : : polycrystalline quartz with two to three subcrytals; Qp, >3 : polycrystalline quartz with more than three subcrystals; Qnu : nonundulose monocrystalline quartz; Qu : undulose monocrystalline quartz; Qtot : !total quartz; P : Plagioclase; K : K-feldspar; Ftot : P+K; Lm :metamorphic lithic fragment; Lv : volcanic lithic fragment; Ls : sedimentary lithic fragment; Ltot : Lm+Lv+Ls

60

Table 5. SEM-CL modal counting data and percentage of detrital quartz grains from the Sindong Group sandstones.

Fm. Part Sample P V M LM MM HM Total

North

ND

Lower H0706-3 147 (49.8%) 0 (0.0%) 148 (50.2%) 12 (4.1%) 103 (34.9%) 33 (11.2%) 295

Middle H0705-5 150 (35.0%) 2 (0.5%) 277 (64.6%) 21 (4.9%) 165 (38.5%) 91 (21.2%) 429

Upper 0107-4 144 (34.0%) 0 (0.0%) 279 (66.0%) 23 (5.4%) 195 (46.1%) 61 (14.4%) 423

HSD

Lower H0707-2 164 (48.4%) 2 (0.6%) 173 (51.0%) 8 (2.4%) 133 (39.2%) 32 (9.4%) 339

Middle 0107-7 105 (25.9%) 1 (0.2%) 299 (73.8%) 17 (4.2%) 212 (52.3%) 80 (19.8%) 405

Upper H0707-5 130 (29.5%) 1 (0.2%) 309 (70.2%) 15 (3.4%) 246 (55.9%) 48 (10.9%) 440

JJ

Lower H0707-14 214 (43.4%) 4 (0.8%) 275 (55.8%) 43 (8.7%) 188 (38.1%) 44 (8.9%) 493

Middle 630-9 94 (26.0%) 4 (1.1%) 264 (72.9%) 26 (7.2%) 203 (56.1%) 35 (9.7%) 362

Upper 0107-9 127 (25.2%) 6 (1.2%) 371 (73.6%) 8 (1.6%) 241 (47.8%) 122 (24.2%) 504

Middle

ND

Lower 0722-3 198 (41.9%) 5 (1.1%) 270 (57.1%) 9 (1.9%) 149 (31.5%) 112 (23.7%) 473

Middle 0113-12 325 (43.3%) 14 (1.9%) 412 (54.9%) 38 (5.1%) 206 (27.4%) 168 (22.4%) 751

Upper 0722-6 186 (47.2%) 7 (1.8%) 201 (51.0%) 14 (3.6%) 118 (29.9%) 69 (17.5%) 394

HSD

Lower 0722-7 176 (35.6%) 14 (2.8%) 304 (61.5%) 3 (0.6%) 192 (38.9%) 109 (22.1%) 494

Middle 0722-8 126 (38.4%) 6 (1.8%) 196 (59.8%) 7 (2.1%) 106 (32.3%) 83 (25.3%) 328

Upper 0722-11 121 (29.0%) 8 (1.9%) 288 (69.1%) 7 (1.7%) 193 (46.3%) 88 (21.1%) 417

JJ

Lower 0113-5 194 (46.7%) 15 (3.6%) 206 (49.6%) 30 (7.2%) 108 (26.0%) 68 (16.4%) 415

Middle 072506-1 199 (32.3%) 38 (6.2%) 380 (61.6%) 23 (3.7%) 251 (40.7%) 106 (17.2%) 617

Upper 0722-16 70 (32.4%) 20 (9.3%) 126 (58.3%) 15 (6.9%) 94 (43.5%) 17 (7.9%) 216

61

Table 5. (Continued)

South

ND Lower ND-3 58 (19.7%) 1 (0.3%) 235 (79.9%) 19 (6.5%) 209 (71.1%) 7 (2.4%) 294

Middle ND-5 119 (19.1%) 14 (2.2%) 491 (78.7%) 15 (2.4%) 348 (55.8%) 128 (20.5%) 624

Upper 0707-4 122 (21.7%) 1 (0.2%) 438 (78.1%) 8 (1.4%) 319 (56.9%) 111 (19.8%) 561

HSD Lower 0106-1 120 (27.0%) 15 (3.4%) 309 (69.6%) 10 (2.3%) 207 (46.6%) 92 (20.7%) 444

Middle 0703-10 188 (26.2%) 24 (3.3%) 506 (70.5%) 4 (0.6%) 364 (50.7%) 138 (19.2%) 718

Upper 0106-3 119 (25.2%) 14 (3.0%) 340 (71.9%) 10 (2.1%) 217 (45.9%) 113 (23.9%) 473

JJ Lower 0704-4 64 (23.5%) 3 (1.1%) 205 (75.4%) 5 (1.8%) 152 (55.9%) 48 (17.6%) 272

Middle 0106-8 88 (22.7%) 15 (3.9%) 284 (73.4%) 8 (2.1%) 158 (40.8%) 118 (30.5%) 387

Upper 0106-11 43 (21.9%) 48 (24.5%) 105 (53.6%) 1 (0.5%) 94 (48.0%) 7 (3.6%) 196

P=plutonic quartz, V=volcanic quartz, M=metamorphic quartz, LM=low-grade metamorphic quartz, MM=medium-grade metamorphic quartz, HM=high-grade metamorphic quartz

62

Table 6. The Sindong Group detrital zircons divided by the mantle-derived anorogenic magmatic and the crust-derived orogenic magmatic zircon

Orogenic

magmatic zircon Anorogenic

magmatic zircon

(Zr/Hf < 50) (Zr/Hf > 50)

Northern part

Nakdong Fm. 37.0% (30) 63.0% (51)

Hasandong Fm. 80.2% (73) 19.8% (18)

Jinju Fm. 94.6% (70) 5.4% (4)

Orogenic

magmatic zircon Anorogenic

magmatic zircon

(Zr/Hf < 50) (Zr/Hf > 50)

Middle part

Nakdong Fm. 80.0% (68) 20.0% (17)

Hasandong Fm. 87.5% (49) 12.5% (7)

Jinju Fm. 80.7% (88) 19.3% (21)

Orogenic

magmatic zircon Anorogenic

magmatic zircon

(Zr/Hf < 50) (Zr/Hf > 50)

Southern part

Nakdong Fm. 59.6% (28) 40.4% (19)

Hasandong Fm. 68.9% (31) 31.1% (14)

Jinju Fm. 63.3% (31) 36.7% (18)

63

Table 7. Kolomogorov-Schmirnoff P-values for the zircon Zr/Hf ratios in the studied Sindong Group samples.

North

ND North HSD

North JJ

Middle ND

Middle HSD

Middle JJ

South ND

South HSD

South JJ

North ND 0 0 0 0 0 0 0 0.025

North HSD 0 0 0.578 0.058 0.011 0.056 0.309 0.009

North JJ 0 0 0 0.057 0.064 0 0 0

Middle ND 0 0.578 0 0.045 0.009 0.146 0.484 0.023

Middle HSD 0 0.058 0.057 0.045 0.75 0.002 0.015 0

Middle JJ 0 0.011 0.064 0.009 0.75 0 0.004 0

South ND 0 0.056 0 0.146 0.002 0 0.254 0.464

South HSD 0 0.309 0 0.484 0.015 0.004 0.254 0.101

South JJ 0.025 0.009 0 0.023 0 0 0.464 0.101

64

국문초록

경상분지의 전기백악기 신동층군 사암의 기원암에 대해 연구하였다.

기원암을 추적하기 위해서 신동층군 사암의 주구성광물의 조성을

연구하였고, SEM-CL 을 이용하여 석영 입자의 미세조직을 분석하였으며,

저어콘 입자들의 Zr/Hf 비율을 분석하였다.

이 신동층군 사암의 기원암 연구를 통해, 초기 백악기에

주향이동단층이 활발한 동아시아 대륙연변부에서 퇴적이 시작되어

신동층군이 퇴적되었을 시기의 기원지의 지질을 재구성하였다.

신동층군이 쌓이는 동안 기원지의 지질에서는 큰 변화는 나타나지

않았다. 기원지에는 주로 편마암류, 화강암류, (변성)퇴적암류와 같은

상부지각 조성의 암석들이 분포하였다 (선캠브리아 화강편마암, 고생대

변성퇴적암류, 삼첨기 화강암류, 쥐라기 화강암류 등). 하산동층과

진주층에서는 화산암으로부터 온 퇴적성분들을 포함하지만, 기원

화산암은 현재는 지표에서 찾아볼 수 없다. 그러나 화산암의 특징들을

가지는 퇴적물들은 하산동층과 진주층이 퇴적될 시기에 대륙 화산호가

나타나기 시작했으며, 상부 진주층이 퇴적될 때 심한 화산활동이

나타났음을 지시한다. 또한 경상분지 북부지역의 사암에서는 화산암의

65

특성을 지닌 퇴적물이 거의 나타나지 않는 것을 보면 화산암류는

경상분지 중, 남부의 기원지에만 국한 되었음을 지시한다.

저어콘 입자들의 Zr/Hf 비를 통해서는 저어콘 입자들의 기원암을

조산대의 암석과 비조산대 암석으로 분류할 수 있었고, 대체로 조산대의

암석으로부터 온 저어콘들이 60~95%정도로 지배적으로 나타나는 것에

반해, 북부 지역의 낙동층에서는 비조산대의 암석에서 온 저어콘이 60%

이상 나타나며 이는 삼첩기에 형성된 비조산대 화강암류이다.

주요어 : SEM-CL, 신동층군, 사암, 기원지, 저어콘, Zr/Hf 비