[ RadSafe ] FW: FW: Queen's helps produce archaeological 'time machine'
Dan W McCarn
hotgreenchile at gmail.com
Mon Feb 15 09:46:07 CST 2010
Attached are three publications / Abstracts describing the development of
Prof. Paula Reimer et al radiocarbon database. Anyone wishing to have the
original pdfs, please request them directly to me and I will provide them
(They are too large to include as an attachment).
I might point-out that these data are critical to the dating of marine
sediments and ice cores, and while mainly useful for archeologists, I'm sure
that there are quite a few applications for climate studes...
1) RADIOCARBON, Vol 44, Nr 3, 2002, p 653-661 C 2002 by the Arizona Board of
Regents on behalf of the University of Arizona; PRELIMINARY REPORT OF THE
FIRST WORKSHOP OF THE INTCAL04 RADIOCARBON CALIBRATION/COMPARISON WORKING
GROUP, Paula J Reimer1 . Konrad A Hughen2 . Thomas P Guilderson1 . Gerry
McCormac3 . Mike G L Baillie3 . Edouard Bard4 . Phillip Barratt3 . J Warren
Beck5 . Caitlin E Buck6 . Paul E Damon7 . Michael Friedrich8 . Bernd Kromer9
. Christopher Bronk Ramsey10 . Ron W Reimer3 . Sabine Remmele8 . John R
Southon11 . Minze Stuiver12 . Johannes van der Plicht13
ABSTRACT. The first meeting of the IntCal04 working group took place at
Queen's University Belfast from April 15 to 17, 2002. The participants are
listed as co-authors of this report. The meeting considered criteria for the
acceptance of data into the next official calibration dataset, the
importance of including reliable estimates of uncertainty in both the
radiocarbon ages and the cal ages, and potential methods for combining
datasets. This preliminary report summarizes the criteria that were
discussed, but does not yet give specific recommendations for inclusion or
exclusion of individual datasets.
2) RADIOCARBON, Vol 46, Nr 3, 2004, p 1029-1058 C 2004 by the Arizona Board
of Regents on behalf of the University of Arizona; INTCAL04 TERRESTRIAL
RADIOCARBON AGE CALIBRATION, 0-26 CAL KYR BP; Paula J Reimer1,2 . Mike G L
Baillie2 . Edouard Bard3 . Alex Bayliss4 . J Warren Beck5 . Chanda J H
Bertrand6 . Paul G Blackwell7 . Caitlin E Buck7 . George S Burr5 . Kirsten B
Cutler8 . Paul E Damon5 . R Lawrence Edwards8 . Richard G Fairbanks9 .
Michael Friedrich10 . Thomas P Guilderson1,17 . Alan G Hogg11 . Konrad A
Hughen6 . Bernd Kromer12 . Gerry McCormac2 . Sturt Manning13,14 .
Christopher Bronk Ramsey15 . Ron W Reimer2,16 . Sabine Remmele11 . John R
Southon17 . Minze Stuiver18 . Sahra Talamo12 . F W Taylor19 . Johannes van
der Plicht20 . Constanze E Weyhenmeyer1
ABSTRACT. A new calibration curve for the conversion of radiocarbon ages to
calibrated (cal) ages has been constructed and internationally ratified to
replace IntCal98, which extended from 0-24 cal kyr BP (Before Present, 0 cal
BP = AD 1950). The new calibration data set for terrestrial samples extends
from 0-26 cal kyr BP, but with much higher resolution beyond 11.4 cal kyr BP
than IntCal98. Dendrochronologically-dated tree-ring samples cover the
period from 0-12.4 cal kyr BP. Beyond the end of the tree rings, data from
marine records (corals and foraminifera) are converted to the atmospheric
equivalent with a site-specific marine reservoir correction to provide
terrestrial calibration from 12.4-26.0 cal kyr BP. A substantial enhancement
relative to IntCal98 is the introduction of a coherent statistical approach
based on a random walk model, which takes into account the uncertainty in
both the calendar age and the 14C age to calculate the underlying
calibration curve (Buck and Blackwell, this issue). The tree-ring data sets,
sources of uncertainty, and regional offsets are discussed here.
The marine data sets and calibration curve for marine samples from the
surface mixed layer (Marine04) are discussed in brief, but details are
presented in Hughen et al. (this issue a). We do not make a recommendation
for calibration beyond 26 cal kyr BP at this time; however, potential
calibration data sets are compared in another paper (van der Plicht et al.,
3) RADIOCARBON, Vol 46, Nr 3, 2004, p 1059-1086 C 2004 by the Arizona Board
of Regents on behalf of the University of Arizona; MARINE04 MARINE
RADIOCARBON AGE CALIBRATION, 0-26 CAL KYR BP; Konrad A Hughen1 . Mike G L
Baillie2 . Edouard Bard3 . J Warren Beck4 . Chanda J H Bertrand1 . Paul G
Blackwell5 . Caitlin E Buck5 . George S Burr6 . Kirsten B Cutler7 . Paul E
Damon6 . Richard L Edwards8 . Richard G Fairbanks9 . Michael Friedrich10 .
Thomas P Guilderson11,16 . Bernd Kromer12 . Gerry McCormac2 . Sturt
Manning13,14 . Christopher Bronk Ramsey15 . Paula J Reimer2,11 . Ron W
Reimer16 . Sabine Remmele10 . John R Southon17 . Minze Stuiver18 . Sahra
Talamo12 . F W Taylor19 . Johannes van der Plicht20,21 . Constanze E
ABSTRACT. New radiocarbon calibration curves, IntCal04 and Marine04, have
been constructed and internationally ratified to replace the terrestrial and
marine components of IntCal98. The new calibration data sets extend an
additional 2000 yr, from 0-26 cal kyr BP (Before Present, 0 cal BP = AD
1950), and provide much higher resolution, greater precision, and more
detailed structure than IntCal98. For the Marine04 curve,
dendrochronologically-dated tree-ring samples, converted with a box
diffusion model to marine mixed-layer ages, cover the period from 0-10.5 cal
kyr BP. Beyond 10.5 cal kyr BP, high-resolution marine data become available
from foraminifera in varved sediments and U/Th-dated corals. The marine
records are corrected with site-specific 14C reservoir age information to
provide a single global marine mixed-layer calibration from 10.5-26.0 cal
kyr BP. A substantial enhancement relative to IntCal98 is the introduction
of a random walk model, which takes into account the uncertainty in both the
calendar age and the 14C age to calculate the underlying calibration curve
(Buck and Blackwell, this issue). The marine data sets and calibration curve
for marine samples from the surface mixed layer (Marine04) are discussed
here. The tree-ring data sets, sources of uncertainty, and regional offsets
are presented in detail in a companion paper by Reimer et al. (this issue).
Dan W McCarn, Geologist
2867 A Fuego Sagrado
Santa Fe, NM 87505
+1-505-310-3922 (Mobile - New Mexico)
HotGreenChile at gmail.com (Private email)
From: Paula Reimer [mailto:p.j.reimer at qub.ac.uk]
Sent: Monday, February 15, 2010 07:42
To: hotgreenchile at gmail.com
Subject: Re: FW: Queen's helps produce archaeological 'time machine'
While the main benefactors of the new radiocarbon calibration curve may
be archaeologists, radiocarbon dating is also used extensively in dating
terrestrial and marine sediments in the late Quaternary in many areas of
research. It will certaintly cause a re-evaluation of dates in some
instances . However the new curve may not actually reduce the +/- on the
results since previous methods for calibrating radiocarbon ages older
than 26,000 cal BP often ignored various sources of uncertainty.
I've attached a paper which sets out the criteria for acceptance of data
into the IntCal database and the papers produced in 2004.
Please let me know if you have further questions or comments.
Lisa McElroy wrote:
> Dear Paula,
> I have received the email below re your calibration curve and have
> informed the gentlemen that I will forward their request for further
> discussion on to you.
> Kind regards,
> *Lisa McElroy***
> *Senior Press Officer*
> *Marketing, Recruitment and Communications*
> *Lanyon North*
> *Queen's University Belfast*
> *University Road*
> *BT7 1NN*
> *Tel: 00 44 (0)28 90 97 5384*
> *Mob: 00 44 (0)781 44 22 572*
> *Email: **Lisa.Mitchell at qub.ac.uk* <mailto:Lisa.Mitchell at qub.ac.uk>
> Need an expert?
> Visit www.qub.ac.uk/expertsdirectory
> *From:* Dan W McCarn [mailto:hotgreenchile at gmail.com]
> *Sent:* 14 February 2010 13:55
> *To:* '*** ******'
> *Cc:* radsafe at radlab.nl; Lisa McElroy
> *Subject:* RE: Queen's helps produce archaeological 'time machine'
> Dear Roy:
> As a geologist dealing with ore deposits considerably older than
> 50,000 years, I've not been able to use radiocarbon dating and usually
> stick to uranium-series data. As the title suggests, the main
> benefactors of this research & discussion will be archeologists. I'm
> usually more concerned with radiometric equilibrium within sandstone
> uranium ISR deposits as well as differential isotopic leachability of
> ore bodies when exposed to different leach solutions (e.g. especially
> U238 - U234). As the article mentions, "It has taken nearly 30 years
> for researchers to produce a calibration curve this far back in time.
> Since the early 1980s, an international working group called INTCAL
> has been working on the project." I remember having coffee every day
> for 8 years with the Nuclear Data Section of the IAEA, and the intense
> effort and intercalibration exercises with numerous laboratories
> including Seibersdorf in preparing their series of databases. I hope
> that INTCAL will be equally successful. I would certainly hope that
> INTCAL has been through a similar critical review.
> Perhaps *Lisa McElroy* might join in this discussion and explain the
> significance of the new calibration data and methods I'm sure that
> much of the discussion will be related to potential contamination of
> modern materials, sampling methodology, QA/QC, and intercalibration
> resulting in the current database.
> Dan ii
> Dan W McCarn, Geologist
> 2867 A Fuego Sagrado
> Santa Fe, NM 87505
> +1-505-310-3922 (Mobile - New Mexico)
> HotGreenChile at gmail.com <mailto:HotGreenChile at gmail.com> (Private email)
> *From:* *** ****** [mailto:royherren2005 at yahoo.com]
> *Sent:* Saturday, February 13, 2010 22:24
> *To:* Dan W McCarn
> *Cc:* radsafe at radlab.nl
> *Subject:* Queen's helps produce archaeological 'time machine'
> Its not entirely clear from the following articles just exactly how
> the "new calibration curve" will change our perspective of the
> historic passage of time. It will be interesting to see how much
> smaller the +/- range will be on estimates of the age of specimens.
> Will this new calibration curve cause a "re-evaluation" of older data?
> What is your take on this news?
> *Queen's helps produce archaeological 'time machine' *
> Researchers at Queen's have helped produce a new archaeological tool
> which could answer key questions in human evolution.
> The new calibration curve, which extends back 50,000 years, is a major
> landmark in radiocarbon dating - the method used by archaeologists and
> geoscientists to establish the age of carbon-based materials. It could
> help research issues including the effect of climate change on human
> adaption and migrations.
> The project was led by Queen's University Belfast through a National
> Environment Research Centre (NERC) funded research grant to Dr Paula
> Reimer and Professor Gerry McCormac from the Centre for Climate, the
> Environment and Chronology (14CHRONO) at Queen's and statisticians at
> the University of Sheffield. Ron Reimer and Professor Emeritus Mike
> Baillie from Queen's School of Geography, Archaeology and
> Palaeoecology also contributed to the work.
> The curve called INTCAL09, has just been published in the journal
> /Radiocarbon/. It not only extends radiocarbon calibration but also
> considerably improves earlier parts of the curve.
> Dr Reimer said: "The new radiocarbon calibration curve will be used
> worldwide by archaeologists and earth scientists to convert
> radiocarbon ages into a meaningful time scale comparable to historical
> dates or other estimates of calendar age.
> "It is significant because this agreed calibration curve now extends
> over the entire normal range of radiocarbon dating, up to 50,000 years
> before today. Comparisons of the new curve to ice-core or other
> climate archives will provide information about changes in solar
> activity and ocean circulation."
> It has taken nearly 30 years for researchers to produce a calibration
> curve this far back in time. Since the early 1980s, an international
> working group called INTCAL has been working on the project.
> The principle of radiocarbon dating is that plants and animals absorb
> trace amounts of radioactive carbon-14 from carbon dioxide in the
> atmosphere while they are alive but stop doing so when they die. The
> carbon-14 decays from archaeological and geological samples so the
> amount left in the sample gives an indication of how old the sample is.
> As the amount of carbon -14 in the atmosphere is not constant, but
> varies with the strength of the earth's magnetic field, solar activity
> and ocean radiocarbon ages must be corrected with a calibration curve.
> Most experts consider the technical limit of radiocarbon dating to be
> about 50,000 years, after which there is too little carbon-14 left to
> measure accurately with present day technology.
> Further information on the work of Queen's Chrono Centre can be found
> online at http://chrono.qub.ac.uk/
> *Media inquiries to Lisa McElroy, Press and PR Unit. Tel: +44 (0)28
> 9097 5384 or email **lisa.mcelroy at qub.ac.uk*
> <mailto:lisa.mcelroy at qub.ac.uk> *.*
Prof. Paula J. Reimer
Director, Centre for Climate, the Environment & Chronology (14CHRONO)
Director of Research Environmental Change cluster
School of Geography, Archaeology and Palaeoecology
Queen's University Belfast
e-mail: p.j.reimer at qub.ac.uk
Phone: 028 9097 3980
Phone: +44 28 9097 3980
FAX: +44 28-9097-3897
Archaeology & Palaeoecology Building
Queen's University Belfast
42 Fitzwilliam Street
Belfast BT9 6AX
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