Radiogenic isotope records of Quaternary glaciations: Changes in the erosional source and weathering processes

Variations of global and regional silicate weathering rates and paleo-ocean circulation patterns are estimated by using radiogenic isotope records, but the effects of changes in provenance are generally ignored. Here sediment provenance has been constrained through the use of Ar-Ar ages for individu...

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Bibliographic Details
Published in:Geology
Main Authors: Reynolds, B, Sherlock, S, Kelley, S, Burton, K
Format: Article in Journal/Newspaper
Language:English
Published: 2016
Subjects:
Online Access:https://doi.org/10.1130/G20734.1
https://ora.ox.ac.uk/objects/uuid:bb07b80e-b529-441e-982e-b1afd25fea34
Description
Summary:Variations of global and regional silicate weathering rates and paleo-ocean circulation patterns are estimated by using radiogenic isotope records, but the effects of changes in provenance are generally ignored. Here sediment provenance has been constrained through the use of Ar-Ar ages for individual detrital minerals from the Labrador Sea, which can be compared directly to the radiogenic isotope compositions from the same core material. Dramatic changes in the radiogenic isotope composition of North Atlantic Deep Water through the Quaternary Period are shown to reflect discrete changes in both sources and weathering processes accompanying Northern Hemisphere glaciation. Changes in the different radiogenic isotope systems reflect the influence of source, physical weathering, and chemical weathering, and not simply changes in the underlying weathering rate or ocean circulation patterns that are typically inferred. © 2004 Geological Society of America.