Featured Research

from universities, journals, and other organizations

A sharper look into the past for archaeology and climate research

Date:
October 19, 2012
Source:
Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences
Summary:
By using a new series of measurements of radiocarbon dates on seasonally laminated sediments from Lake Suigetsu in Japan, a more precise calibration of radiocarbon dating will be possible. In combination with an accurate count of the seasonal layered deposits in the lake, the study resulted in an unprecedented precision of the known 14C method with which it is now possible to date older objects of climate research and archeology more precisely than previously achievable.

Drilling work to retreive a varve core from Lake Suigetsu, Japan.
Credit: © Achim Brauer / GFZ

By using a new series of measurements of radiocarbon dates on seasonally laminated sediments from Lake Suigetsu in Japan, a more precise calibration of radiocarbon dating will be possible. In combination with an accurate count of the seasonal layered deposits in the lake, the study resulted in an unprecedented precision of the known 14C method with which it is now possible to date older objects of climate research and archeology more precisely than previously achievable. This is the result published by an international team of geoscientists led by Prof. Christopher Bronk Ramsey (University of Oxford) in the latest edition of the journal Science.

The radiocarbon method for dating organic and calcareous materials uses the known decay rates of the radioactive isotope 14C, which is formed in very small amounts in the upper atmosphere by cosmic rays. Since the formation of 14C is affected by Earth's magnetic field and solar activity and is therefore not constant, this relative time scale is has no absolute timestamp in calendar years. The timescale developed through the measured decay rates must thus be calibrated to indicate the age in calendar years. This works best with a parallel count of annual layers in lake sediments or tree rings. A calibration reaching very far into the past was now possible with data from the Suigetsu Lake, located in Mikata near the Sea of Japan. Here, a drill core could be retrieved from the sediments whose seasonal resolution dates back to over 50,000 years ago.

These new data are very important for both archaeological and paleoclimatic research. "With such information, one can not only improve the understanding of regional impacts of climate change, but also find the triggering mechanisms ," explains Achim Brauer, who is one of the initiators of the project and responsible for creating the time scale in calendar years of the Suigetsu sediment profile at the GFZ German Research Centre for Geosciences. "It allows us to synchronize paleoclimatic key profiles from different regions, such as the Arctic, East Asia and Europe more accurately, in order to determine whether abrupt climate changes occurred worldwide at the same time, or whether changes in some regions can be identified as sooner than others. The new calibration also allows a more accurate determination of the extinction times of the Neanderthals and the temporal spread of modern humans in Europe. "

The Suigetsu Lake is ideal for using both dating methods, measurement of 14C and counting of annual layers, because deciduous trees grew on its shores during the last ice age, the leaves of which were preserved in large numbers in the sediments and are ideal for 14C dating. At the same time, this lake is one of the rare cases in which annual layers have been preserved in the sediment.

Due to the long experience of Achim Brauer's working group with creating precise calendar time scales from lake sediments, the GFZ scientists were entrusted with this task. Using special microscope techniques, it was possible to decipher the detailed structure of the finest, thousands of years old layers in the Suigetsu sediments. The scientists identified springtime layers which were formed by the melting of snow, summer layers of organic material or algae residues, fall layers of a special iron carbonate and winter layers of fine clay. The knowledge of this seasonal rhythm of sedimentation was the basis for the exact annual layer timescale. The high quality of the new Suigetsu chronology for the period from 12500 to 52800 years before present is shown by the fact that it was selected as the basis for the next iteration of the IntCal compilation, an internationally valid composite record of radiocarbon calibration.


Story Source:

The above story is based on materials provided by Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences. Note: Materials may be edited for content and length.


Journal Reference:

  1. C. Bronk Ramsey, R. A. Staff, C. L. Bryant, F. Brock, H. Kitagawa, J. van der Plicht, G. Schlolaut, M. H. Marshall, A. Brauer, H. F. Lamb, R. L. Payne, P. E. Tarasov, T. Haraguchi, K. Gotanda, H. Yonenobu, Y. Yokoyama, R. Tada, T. Nakagawa. A Complete Terrestrial Radiocarbon Record for 11.2 to 52.8 kyr B.P.. Science, 2012; 338 (6105): 370 DOI: 10.1126/science.1226660

Cite This Page:

Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences. "A sharper look into the past for archaeology and climate research." ScienceDaily. ScienceDaily, 19 October 2012. <www.sciencedaily.com/releases/2012/10/121019071419.htm>.
Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences. (2012, October 19). A sharper look into the past for archaeology and climate research. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2012/10/121019071419.htm
Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences. "A sharper look into the past for archaeology and climate research." ScienceDaily. www.sciencedaily.com/releases/2012/10/121019071419.htm (accessed April 23, 2014).

Share This



More Fossils & Ruins News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Mich. Boy Unearths 10,000-Year-Old Mastodon Tooth

Mich. Boy Unearths 10,000-Year-Old Mastodon Tooth

Newsy (Apr. 20, 2014) — A 9-year-old Michigan boy was exploring a creek when he came across a 10,000-year-old tooth from a prehistoric mastodon. Video provided by Newsy
Powered by NewsLook.com
Couple Finds Love Letters From WWI In Attic

Couple Finds Love Letters From WWI In Attic

Newsy (Apr. 17, 2014) — A couple found love letters from World War I in their attic. They were able to deliver them to relatives of the writer of those letters. Video provided by Newsy
Powered by NewsLook.com
Erotic Art Offers Glimpse of China's 'lost' Sexual Philosophy

Erotic Art Offers Glimpse of China's 'lost' Sexual Philosophy

AFP (Apr. 16, 2014) — Explicit Chinese art works dating back centuries go on display in Hong Kong, revealing China's ancient relationship with sex. Video provided by AFP
Powered by NewsLook.com
French Historians Fight to Save Iconic La Samaritaine Buildings

French Historians Fight to Save Iconic La Samaritaine Buildings

AFP (Apr. 15, 2014) — Parisians and local historians are fighting to save one of the French capital's iconic buildings, the La Samaritaine department store. Duration: 01:42 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

More Coverage


'Time-Capsule' Japanese Lake Sediment Advances Radiocarbon Dating for Older Objects

Oct. 18, 2012 — A series of radiocarbon measurements from Japan's Lake Suigetsu will give scientists a more accurate benchmark for dating materials, especially for older objects. Researchers extracted cores ... read more
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins