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Full-Text Articles in Physical Sciences and Mathematics
Benthic Foraminifera As Tools Of Paleoceanography: Three Case Studies From The Late Cretaceous Of The North Pacific Ocean And Western Interior Seaway, And The Miocene-Pleistocene Of The Ross Sea, Antarctica, Serena N. Dameron
Doctoral Dissertations
This dissertation is a widespread compilation of research covering vastly different times and locations. Despite these differences, the use of foraminifera helps to unravel their geologic history, revealing the paleoenvironmental, paleoclimatic, and paleoceanographic conditions of each location. What unites each study is how water mass, food supply and oxygen concentration play a critical role on the microfossil assemblage. This dissertation is broken up into three unique chapters. Chapter 1 reexamines some old ideas of how benthic foraminifera can be used as water mass indicators. A 13-myr record from Shatsky Rise in the paleo-central Pacific Ocean contains several instances water mass …
Oceanographic Controls On The Expression Of Cretaceous Oceanic Anoxic Events In The Western Interior Sea, Christopher M. Lowery
Oceanographic Controls On The Expression Of Cretaceous Oceanic Anoxic Events In The Western Interior Sea, Christopher M. Lowery
Doctoral Dissertations
The Cretaceous Period (145-66 Ma) was a time of elevated global temperatures superimposed on fluctuating climate regimes and repeated biotic turnover. It recorded several major perturbations of the carbon cycle, characterized by widespread deposition of organic-rich black shale and benthic and photic zone dysoxia to euxinia, termed oceanic anoxic events (OAEs). The Cenomanian-Turonian OAE2 and the enigmatic Coniacian-Santonian OAE3 are well-preserved in the Western Interior Sea (WIS) of North America. The expression of these OAEs in the WIS differs both from each other and from contemporaneous open-ocean sections. Despite decades of research, questions remain about the role of oceanographic parameters …
Paleoceanography And Paleoenvironmental Changes Of The Cenomanian-Turonian Boundary Interval (94-93 Ma): The Record Of Oceanic Anoxic Event 2 In The Central And Eastern Parts Of The Western Interior Sea, Khalifa Elderbak
Doctoral Dissertations
The Cenomanian/Turonian (C/T) boundary marine strata of the Late Cretaceous Western Interior Sea (WIS) exhibit a positive carbon isotopic excursion in the bulk-carbonate and organic carbon. This marks Oceanic Anoxic Event 2 (OAE 2), which spans the uppermost part of the Hartland Shale and one-third of the overlying Bridge Creek Limestone members of the Greenhorn Formation and their equivalents. The interval is characterized by alternating beds of light-colored limestone and dark-colored marlstone and calcareous shale. These lithologic couplets have been related to Milankovitch orbital cyclicity. Foraminiferal assemblages from three selected sites, including the C/T boundary Global Boundary Stratotype Section and …