The Western Interior Seaway During Late Cretaceous Oceanic Anoxic Event 2: Paleoceanographic Interpretations Of Foraminiferal Assemblages

Bryant, Raquel

Publication:
The Western Interior Seaway During Late Cretaceous Oceanic Anoxic Event 2: Paleoceanographic Interpretations Of Foraminiferal Assemblages

dc.contributor.advisor	R. Mark Leckie
dc.contributor.author	Bryant, Raquel
dc.contributor.department	University of Massachusetts Amherst
dc.date	2024-03-27T16:52:44.000
dc.date.accessioned	2024-04-26T15:43:13Z
dc.date.available	2024-04-26T15:43:13Z
dc.date.issued	2021-02-01
dc.date.submitted	February
dc.date.submitted	2021
dc.description.abstract	The Cenomanian/Turonian boundary (CTB; ~93.9 Ma) is associated with extreme global warmth, increased volcanism, rising global sea level, and the development of Oceanic Anoxic Event 2 (OAE2; ~94 Myr). The examination of the timing and spatial extent of foraminiferal bio-events associated with the event can illuminate the complex interactions between the ocean, climate, and life during this dynamic interval. Although volcanism has been identified as a primary trigger for OAE2, the impetus for its global expansion is less understood. This work integrates planktic and benthic foraminiferal assemblages and geochemical records from multiple localities across the Western Interior Seaway (WIS) to investigate the potential roles of marginal seas and ocean circulation. The WIS was a shallow, epicontinental sea that extended across western North America during the Late Cretaceous. The present investigations records from five distinct WIS localities through OAE2 time intervals to define a paleoceanographic framework. This framework is used to determine the significance of foraminiferal bio-events, compare the timing of bio-events, rising sea level, water mass changes, and volcanism, and test whether the seaway played a role in the development and expansion of the global OAE2. The investigations find evidence for distinct water masses across North-South and East-West transects of the seaway before OAE2. They demonstrate that the WIS is sensitive to sea-level rise and plays a role in ocean circulation as a brief exporter of intermediate waters. The examination of the timing and spatial extent of foraminiferal bio-events provides compelling evidence for a proposed impetus for the global expansion of OAE2. The widespread development of OAE2 was facilitated by gyre circulation through the WIS, triggered by rising sea level. This work demonstrates the role of paleo-marginal seas in circulation through geologic time and especially during perturbations. It also shows the interplay between local, regional, and global impacts of rapid environmental change and the response and recovery of the marine biosphere.
dc.description.degree	Doctor of Philosophy (PhD)
dc.description.department	Geosciences
dc.identifier.doi	https://doi.org/10.7275/20231817
dc.identifier.orcid	https://orcid.org/0000-0003-3307-4228
dc.identifier.uri	https://hdl.handle.net/20.500.14394/18385
dc.relation.url	https://scholarworks.umass.edu/cgi/viewcontent.cgi?article=3169&context=dissertations_2&unstamped=1
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/4.0/
dc.source.status	published
dc.subject	foraminifera
dc.subject	OAE2
dc.subject	Western Interior Seaway
dc.subject	paleoceanography
dc.subject	micropaleontology
dc.subject	Geochemistry
dc.subject	Geology
dc.subject	Paleobiology
dc.subject	Stratigraphy
dc.title	The Western Interior Seaway During Late Cretaceous Oceanic Anoxic Event 2: Paleoceanographic Interpretations Of Foraminiferal Assemblages
dc.type	campusfive
dc.type	article
dc.type	dissertation
digcom.contributor.author	isAuthorOfPublication\|email:rmbryant@umass.edu\|institution:University of Massachusetts Amherst\|Bryant, Raquel
digcom.identifier	dissertations_2/2094
digcom.identifier.contextkey	20231817
digcom.identifier.submissionpath	dissertations_2/2094
dspace.entity.type	Publication