Middle Miocene oxygen minimum zone expansion offshore West Africa; evidence for global cooling precursor events

Three dissolution events ca. 16 Ma, 15.5 Ma, and 14.3 Ma ago have been identified in sediments from the Congo Fan. Multiproxy benthic foraminiferal and sedimentary records suggest an expanded oxygen minimum zone consistent with enhanced upwelling at these times. Marine carbonate records from adjacen...

Full description

Saved in:
Bibliographic Details
Published in:Geology (Boulder) 2009-08, Vol.37 (8), p.699-702
Main Authors: Kender, Severyn, Peck, V. L, Jones, R. W, Kaminski, M. A
Format: Article
Language:English
Subjects:
Africa
Animals
Atlantic Ocean
benthic taxa
biochemistry
C-13/C-12
carbon
Cenozoic
Climate change
Congo Fan
cooling
Dissolution
Foraminifera
geochemical indicators
geochemistry
Geological time
Invertebrata
isotope ratios
isotopes
Marine ecology
marine environment
marine sediments
microfossils
middle Miocene
Miocene
Neogene
O-18/O-16
oxygen
paleo-oceanography
paleocirculation
paleoclimatology
paleoecology
productivity
Protista
Sedimentation & deposition
sediments
South Atlantic
Southeast Atlantic
stable isotopes
Stratigraphy
submarine fans
Tertiary
upwelling
West Africa
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Three dissolution events ca. 16 Ma, 15.5 Ma, and 14.3 Ma ago have been identified in sediments from the Congo Fan. Multiproxy benthic foraminiferal and sedimentary records suggest an expanded oxygen minimum zone consistent with enhanced upwelling at these times. Marine carbonate records from adjacent North Africa indicate coincident episodes of increased continental weathering, suggesting that an intermittently stronger polar front strengthened west African offshore winds, increasing surface water productivity, and enhanced North African weathering during these events. We propose that Columbia River Flood Basalt volcanism, estimated to have released 106 Tg CO2 and 106 Tg SO2 between 16 and 15.6 Ma ago, may have influenced these climatic changes.
ISSN:0091-7613
1943-2682
DOI:10.1130/G30070A.1