A critical re‐analysis of constraints on the timing and rate of Laurentide Ice Sheet recession in the northeastern United States

Author:

Halsted Christopher T.1ORCID,Bierman Paul R.1,Shakun Jeremy D.2,Davis P. Thompson3,Corbett Lee B.1,Drebber Jason S.1ORCID,Ridge John C.4

Affiliation:

1. Rubenstein School of Environment and Natural Resources, Gund Institute for Environment University of Vermont 81 Carrigan Dr Burlington VT 05405 USA

2. Department of Earth and Environmental Sciences Boston College 140 Commonwealth Avenue Chestnut Hill MA 02467 USA

3. Department of Natural and Applied Sciences Bentley University 175 Forest St Waltham MA 02452 USA

4. Department of Earth and Climate Sciences Tufts University 2 N Hill Rd Medford MA 02155 USA

Abstract

AbstractWe review geochronological data relating to the timing and rate of Laurentide Ice Sheet recession in the northeastern United States and model ice margin movements in a Bayesian framework using compilations of previously published organic 14C (n = 133) and in situ cosmogenic 10Be (n = 95) ages. We compare the resulting method‐specific chronologies with glacial varve records that serve as independent constraints on the pace of ice recession to: (1) construct a synthesis of deglacial chronology throughout the region; and (2) assess the accuracy of each chronometer for constraining the timing of deglaciation. Near the Last Glacial Maximum terminal moraine zone, 10Be and organic 14C ages disagree by thousands of years and limit determination of the initial recession to a date range of 24–20 ka. We infer that 10Be inherited from pre‐glacial exposure adds 2–6 kyr to many exposure ages near the terminal moraines, whereas macrofossil 14C ages are typically 4–8 kyr too young due to a substantial lag between ice recession and sufficient organic material accumulation for dating in some basins. Age discrepancies between these chronometers decrease with distance from the terminal moraine, due to less 10Be inherited from prior exposure and a reduced lag between ice recession and organic material deposition. 14C and 10Be ages generally agree at locations more than 200 km distal from the terminal moraines and suggest a mostly continuous history of ice recession throughout the region from 18 to 13 ka with a variable pace best documented by varves.

Funder

National Science Foundation

Gund Institute for Environment

Publisher

Wiley

Subject

Paleontology,Earth and Planetary Sciences (miscellaneous),Arts and Humanities (miscellaneous)

Cited by 3 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3