BANN presentatie BANN GREEN Even voorstellen; Bert Blaauw Blaauw Ingenieurs & Adviseurs.
Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography,...
-
Upload
liana-meers -
Category
Documents
-
view
215 -
download
0
Transcript of Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography,...
![Page 1: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/1.jpg)
Radiocarbon age-modellingI – introduction to age-models
Dr. Maarten BlaauwSchool of Geography, Archaeology and Palaeoecology
Queen’s University BelfastNorthern Ireland
![Page 2: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/2.jpg)
My background
Born 1974 in Hardenberg (nl) ‘92-’98 Msc Biology, Groningen (nl) ‘98-‘03 PhD Palaeoecology, Amsterdam (nl) ‘03-’04 Postdoc Trinity College Dublin (ie) ‘04-’06 Postdoc CIMAT (mx) ‘07-... Postdoc Queen’s Univ Belfast (uk)
![Page 3: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/3.jpg)
Today
Lectures
Introduction to age-depth modelling
Bayesian age-depth modelling
PracticalsCalibratingBasic age-depth modellingBayesian age-depth modelling
![Page 4: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/4.jpg)
4
Pollen-diagram
Blaauw et al. in press, The Holocene
![Page 5: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/5.jpg)
5
Poisson random walk
Blaauw et al. in press, The Holocene
![Page 6: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/6.jpg)
6
Blaauw et al. in press, The Holocene
![Page 7: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/7.jpg)
7
Blaauw et al. in press, The Holocene
![Page 8: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/8.jpg)
Types of chronologies
No uncertainties
Yearly resolution
Decadal / centennial – (multi-) millennial resolution
![Page 9: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/9.jpg)
![Page 10: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/10.jpg)
Annually layered ice cores
![Page 11: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/11.jpg)
History peat dating
Pre 14C dating (relative dating) Peat stratigraphy (Sernander 1866-1944) & pollen Link pollen with archaeology (bronze age etc.) Link with Swedish varve chronology (de Geer) (Sub) millennial precision
Von Post 1946
![Page 12: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/12.jpg)
History peat dating
Carbon dating → 'absolute', independent dates Smith & Pilcher 1973: 14C dating vs. pollen zones 'Wishful thinking obscures reality' (von Post 1946)
14C date depths along peat core At levels with major proxy changes At regular intervals
Assume linear accumulation between dated levels e.g.: Aaby 1976, van Geel 1978
![Page 13: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/13.jpg)
History peat dating
High-resolution 14C dating wiggle-match dating (van Geel&Mook 1989) Bayesian (e.g., Blaauw&Christen 2005) post-bomb dating (e.g., van der Linden et al. 2008)
Tephra (e.g., Pilcher et al. 1995, Davies et al. 2003) 210Pb dating (e.g., Turetsky et al. 2004) All form age estimates for age-depth models
The estimates and models are uncertain
![Page 14: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/14.jpg)
Carbon dating
![Page 15: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/15.jpg)
14C dating
14C unstable, half-life 5568 yr Ratio 14C/C gives age fossil
![Page 16: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/16.jpg)
Tree-ring coverage for IntCal04: until 12.4 kcal BP
Belfast
Groningen
Pretoria
Heidelberg
Waikato
Seattle
PNW/CA German Oak
German Oak
German Oak
German Pine
German Pine
Swiss Pine
Irish Oak
Irish Oak
German Oak
German Oak
![Page 17: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/17.jpg)
Tree-ring coverage for IntCal04
![Page 18: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/18.jpg)
Tree-ring coverage for IntCal04
![Page 19: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/19.jpg)
![Page 20: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/20.jpg)
http:///www.chrono.qub.ac.uk/blaauw/
![Page 21: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/21.jpg)
Age-depth modelling
So now we have dates... what's next? Estimate ages of non-dated levels Use available information
all dates together environmental settings site other comparable archives
![Page 22: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/22.jpg)
Age-depth modelling
14C and other dates Basic age-modelling techniques
interpolation, regression, spline, ...
Bayesian approaches chron. ordering, wiggle-match dating
Compare multiple archives tuning, eye-balling, Bayesian
![Page 23: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/23.jpg)
Age-depth modelling
![Page 24: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/24.jpg)
Age-depth modelling
![Page 25: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/25.jpg)
Uncertainty accumulation
![Page 26: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/26.jpg)
Many date$
![Page 27: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/27.jpg)
Few dates
![Page 28: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/28.jpg)
![Page 29: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/29.jpg)
Which age-depth model?
800 cm core 9 14C dates surface = recent
![Page 30: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/30.jpg)
Which age-depth model?
800 cm core 9 14C dates surface = recent Linear interpol.
Too much weight on individual dates?
![Page 31: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/31.jpg)
Which age-depth model?
800 cm core 9 14C dates surface = recent Linear interpol.
date 6 = outlier
![Page 32: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/32.jpg)
Which age-depth model?
800 cm core 9 14C dates surface = recent Linear interpol.
470 cm = hiatus
![Page 33: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/33.jpg)
Which age-depth model?
800 cm core 9 14C dates surface = recent Linear interpol. Linear regression
470 cm = hiatus
Too narrow error ranges?
![Page 34: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/34.jpg)
Which age-depth model?
800 cm core 9 14C dates surface = recent Linear interpol. Linear regression Polyn. regression
470 cm = hiatus
second degreewide uncertainties when extrapolating!
![Page 35: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/35.jpg)
Which age-depth model?
800 cm core 9 14C dates surface = recent Linear interpol. Linear regression Polyn. regression Smooth spline
![Page 36: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/36.jpg)
Which age-depth model?
800 cm core 9 14C dates surface = recent Linear interpol. Linear regression Polyn. regression Smooth spline
date 6 = outlier
![Page 37: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/37.jpg)
Which age-depth model?
800 cm core 9 14C dates surface = recent Linear interpol. Linear regression Polyn. regression Smooth spline
470 cm = hiatus
![Page 38: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/38.jpg)
Age-depth modelling
How did our sediment accumulate over time? Constant? Varying? Pulses? Hiatuses? Site settings Should we try to fit a curve through all dates?
Balance belief in dates and belief in model Use stratigraphic information
How many dates do I need? The more, the better? The more problems? Depends on your questions
“is my sediment of glacial age?” “early 8.2 k event?”
![Page 39: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/39.jpg)
Dating uncertainties
![Page 40: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/40.jpg)
14C dating
![Page 41: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/41.jpg)
14C dating
![Page 42: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/42.jpg)
Uncertainties dates
5 calibrated dates surface = recent simulate yr every date draw age-model
linear interpolation
repeat
![Page 43: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/43.jpg)
Uncertainties dates
5 calibrated dates surface = recent simulate yr every date draw age-model
polynomial regression does not cross all dots weighted by error sizes
repeat
![Page 44: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/44.jpg)
Uncertainties dates
![Page 45: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/45.jpg)
Basic age-modelling
Choose which one looks nicest... How treat point estimates? (mid/max, multimodal)
Why just one line?
Not much literature Bennett 1994, Bennett and Fuller 2002, The Holocene,
Telford et al. 2004, QSR Software
Calib + Excel clam, Blaauw in press (Quaternary Geochronology)
![Page 46: Radiocarbon age-modelling I – introduction to age-models Dr. Maarten Blaauw School of Geography, Archaeology and Palaeoecology Queens University Belfast.](https://reader036.fdocuments.net/reader036/viewer/2022062511/5518b5d4550346991f8b5123/html5/thumbnails/46.jpg)
Today
Lectures
Introduction to age-depth modelling
Bayesian age-depth modelling
PracticalsCalibratingBasic age-depth modellingBayesian age-depth modelling