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Degree

MS, Kent State University, College of Arts and Sciences / Department of Geology, 2011.

Abstract

The variation in paleoclimate during the last deglaciation and Holocene were evaluated based on physical and biological variation in the bottom water oxygen level on the Baja margin in Soledad Basin. Sediment from core OXMZ MV99-PC14 raised from a depth of 540m off the Magdalena Margin of Baja California, Mexico was analyzed for the presence of benthic foraminifera, which are presumed to respond to marine productivity and change in bottom water oxygen. This location is an ideal location to study paleoclimate oscillation and ocean and atmospheric interactions due to its shallow sill depth (290m), high sediment rate (~110cm/kr), sensitivity to El Niño Southern Oscillation (ENSO) and ENSO-like variations. Computed Benthic Foraminiferal Oxygen Index (BFOI) and productivity (DSR-Factor3) variations down core showed enhanced productivity and low oxygen during the Mid Holocene. ENSO-like signals were recorded during the Mid Holocene (4-10 cal BP) when the climate witnessed a cold La Niña-like state. A changing pattern of ocean circulation, depth of thermocline and fluctuations in productivity occurred throughout Holocene in Soledad Basin. This was mainly due to the changing budget of oxygen, created primarily by variations in productivity which had an inverse relationship with oxygen levels. Similar variability was found in low and high latitude paleoclimate records from Chukchi shelf, Cariaco Basin, Santa Barbara basin, Point Conception, and Baja California.

Subject Headings

Geology

Keywords

Holocene Paleoclimate; El Niño Southern Oscillation; Benthic Foraminifera; Benthic Foraminiferal Oxygen Index; productivity; bottom water oxygen level

Committee / Advisors

Joseph Ortiz (Advisor)
Elizabeth Griffith (Committee Member)
Jeremy Green (Committee Member)

Pages

83p.

Document number: kent1310628185
Permalink: http://rave.ohiolink.edu/etdc/view?acc_num=kent1310628185

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