Changes in the source of nutrients associated with oceanographic dynamics offshore southern Chile (41°S) over the last 25,000 years

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doi: 10.1016/j.yqres.2013.07.002
Author(s): Verleye, Thomas J.; Martinez, Philippe; Robinson, Rebecca S.; Louwye, Stephen
Author Affiliation(s): Primary:
Ghent University, Department of Geology and Soil Science, Ghent, Belgium
Other:
Université Bordeaux I, France
University of Rhode Island, United States
Volume Title: Quaternary Research
Source: Quaternary Research, 80(3), p.495-501. Publisher: Elsevier, New York, NY, United States. ISSN: 0033-5894 CODEN: QRESAV
Note: In English. 59 refs.; illus., incl. sketch map
Summary: In order to obtain a better knowledge of past oceanographic variability offshore southern Chile, this study reappraises the changes in the sources of nutrients over the last 25ka based on a detailed comparison of previously published nitrogen isotope and microfossil records (dinoflagellate cysts, coccoliths and diatoms) from ODP Site 1233 (41°S). Our findings support the main conclusions of Martinez et al. (2006) in the sense that both the Subantarctic Surface Water and the Gunther Undercurrent are potential sources for the recorded late Quaternary sedimentary δ15N signatures at Site 1233, with variable contributions of both sources during different time periods. This study indicates that Subantarctic Surface Water forms the main source for nutrients during the last glacial maximum (25-18.6 cal ka BP), the first part of the deglaciation (18.6-15.7 cal ka BP) and the Holocene (9.8 cal ka BP until present). An increased contribution of Equatorial Subsurface Water as a source of nutrients to the photic zone offshore southern Chile is observed between 14.4 and 9.8 cal ka BP, which is indicative for upwelling conditions at least after 13.2 cal ka BP as indicated by the microfossil data. Abstract Copyright (2013) Elsevier, B.V.
Year of Publication: 2013
Research Program: ODP Ocean Drilling Program
Key Words: 03 Geochronology; 24 Surficial Geology, Quaternary Geology; Absolute age; Algae; Biostratigraphy; C-14; Carbon; Cenozoic; Chemostratigraphy; Chile; Chronostratigraphy; Cores; Dates; Deglaciation; Diatoms; Dinoflagellata; East Pacific; Glaciation; Holocene; Isotope ratios; Isotopes; Leg 202; Lithostratigraphy; Marine sediments; Microfossils; N-15/N-14; Nitrates; Nitrogen; Nutrients; ODP Site 1233; Ocean Drilling Program; Pacific Ocean; Paleo-oceanography; Palynomorphs; Plantae; Pleistocene; Quaternary; Radioactive isotopes; Sediments; South America; South Pacific; Southeast Pacific; Southern Chile; Stable isotopes; Upper Pleistocene
Coordinates: S410000 S410000 W0742700 W0742700
Record ID: 2014031611
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands