Improving North Atlantic Marine Core Chronologies Using 230Th Normalization

Missiaen, L.; Waelbroeck, C.; Pichat, S.; Jaccard, Samuel; Eynaud, Frederique; Greenop, Rossana; Burke, Andrea (2019). Improving North Atlantic Marine Core Chronologies Using 230Th Normalization. Paleoceanography and paleoclimatology, 34(7), pp. 1057-1073. American Geophysical Union 10.1029/2018PA003444

[img]
Preview
Text
Missiaen et al., 19.pdf - Published Version
Available under License Creative Commons: Attribution-Noncommercial-No Derivative Works (CC-BY-NC-ND).

Download (1MB) | Preview

Producing independent and accurate chronologies for marine sediments is a prerequisite to understand the sequence of millennial‐scale events and reveal potential temporal offsets between marine and continental records, or between different marine records, possibly from different regions. The last 40 ky is a generally well‐constrained period since radiocarbon (14C) can be used as an absolute dating tool. However, in the northern North Atlantic, calendar ages cannot be directly derived from 14C ages, due to temporal and spatial variations of surface reservoir ages. Alternatively, chronologies can be derived by aligning Greenland ice‐core time series with marine surface records. Yet this approach suffers from the lack of clearly defined climatic events between 14.7 and 23.3 cal ky BP (hereafter ka), a crucial period encompassing Heinrich Stadial 1 and the onset of the last deglaciation. In this study, (i) we assess the benefits of 230Th normalization to refine the sedimentation history between surface temperature alignment tie points and (ii) revisit the chronologies of three North Atlantic marine records. Our study supports the contention that the marked increase in the Greenland Ca2+ record at 17.48 ka ± 0.21 ky (1σ) occurred within dating uncertainty of sea surface temperature cooling in the North Atlantic at the onset of Heinrich Stadial 1. This sharp feature might be useful for future chronostratigraphic alignments to remedy the lack of chronological constraint between 14.7 and 23.3 ka for North Atlantic marine records that are subject to large changes in 14C surface reservoir age.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Geological Sciences
10 Strategic Research Centers > Oeschger Centre for Climate Change Research (OCCR)

UniBE Contributor:

Jaccard, Samuel

Subjects:

500 Science > 550 Earth sciences & geology

ISSN:

0883-8305

Publisher:

American Geophysical Union

Language:

English

Submitter:

Samuel Jaccard

Date Deposited:

31 Jul 2019 10:35

Last Modified:

23 Oct 2019 14:33

Publisher DOI:

10.1029/2018PA003444

BORIS DOI:

10.7892/boris.131982

URI:

https://boris.unibe.ch/id/eprint/131982

Actions (login required)

Edit item Edit item
Provide Feedback