Go to  Advanced Search

A novel approach to dissolution correction of Mg/Ca-based paleothermometry in the tropical Pacific

Show full item record

Files in this item

Files Size Format Description   View
Francois_AGU_2007PA001504.pdf 506.9Kb Adobe Portable Document Format   View/Open
Title: A novel approach to dissolution correction of Mg/Ca-based paleothermometry in the tropical Pacific
Author: Francois, Roger; Soon, Maureen
Issue Date: 2007
Publicly Available in cIRcle 2012-01-12
Publisher American Geophysical Union
Citation: Mekik, Figen; Francois, Roger; Soon, Maureen. 2007. A novel approach to dissolution correction of Mg/Ca-based paleothermometry in the tropical Pacific. Paleoceanography 22(3) PA3217. http://dx.doi.org/10.1029/2007PA001504
Abstract: Mg/Ca in planktonic foraminifers carries two main signals: calcification temperature and postdepositional test dissolution. Shell dissolution thus distorts water temperature reconstructions made with Mg/Ca in foraminifers. This problem could be resolved by quantifying the impact of carbonate dissolution on Mg/Ca with an independent, temperature-insensitive deep-sea calcite dissolution proxy, such as the Globorotalia menardii fragmentation index (MFI). To test the validity of this approach, we measured Mg/Ca in the tests of several planktonic foraminifers and MFI in core tops collected over a wide geographic region of the tropical Pacific and covering a wide range of deep-sea calcite dissolution and seawater temperature. We confirm that Mg/Ca from different species have different susceptibility to temperature and dissolution. Mg/Ca in surface-dwelling Globigerina bulloides is controlled by calcification temperature and is largely unaffected by carbonate dissolution estimated from MFI. In contrast, Mg/Ca in deeper dwelling G. menardii is minimally sensitive to temperature and dominantly affected by dissolution. Mg/Ca in Neogloboquadrina dutertrei and Pulleniatina obliquiloculata are significantly affected by both temperature and dissolution, and MFI can be effectively used to correct temperature estimates from these species for calcite dissolution. Additional variables besides temperature and dissolution appear to control Mg/Ca in Globorotalia tumida, and their identification is a prerequisite for interpreting elemental shell composition in this species. Combining down-core measurements of Mg/Ca in multiple foraminifer species with MFI provides a powerful tool for reconstructing past changes in the upper water column temperature structure in the tropical Pacific. An edited version of this paper was published by AGU. Copyright 2007 American Geophysical Union.
Affiliation: Earth and Ocean Sciences, Dept. of (EOS), Dept of
URI: http://hdl.handle.net/2429/40058
Peer Review Status: Reviewed
Scholarly Level: Faculty

This item appears in the following Collection(s)

Show full item record

All items in cIRcle are protected by copyright, with all rights reserved.

UBC Library
1961 East Mall
Vancouver, B.C.
Canada V6T 1Z1
Tel: 604-822-6375
Fax: 604-822-3893