Glomospira acme during the Paleocene-Eocene Thermal Maximum; response to CaCO3 dissolution or to ecological forces?

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doi: 10.2113/gsjfr.43.1.40
Author(s): Arreguín-Rodríguez, Gabriela J.; Alegret, Laia; Ortiz, Silvia
Author Affiliation(s): Primary:
Universidad de Zaragoza, Departamento de Ciencias de la Tierra, Saragossa, Spain
Universidad del Pais Vasco, Spain
Volume Title: Journal of Foraminiferal Research
Source: Journal of Foraminiferal Research, 43(1), p.40-54. Publisher: Cushman Foundation for Foraminiferal Research, Ithaca, NY, United States. ISSN: 0096-1191 CODEN: JFARAH
Note: In English. 99 refs.; illus., incl. 1 table
Summary: The Paleocene-Eocene Thermal Maximum (PETM) event at approximately 55.5 Ma, is characterized by globally elevated temperatures, a negative δ13C excursion and major biotic changes on land and in the oceans, including the major extinction of deep-sea benthic foraminifera. Increased acidity of the oceans and associated shallowing of the calcite compensation depth led to dissolution of deep-sea carbonates In various ocean basins during the PETM. As a result, the post-extinction benthic foraminiferal assemblages, which were locally dominated by agglutinated taxa such as Glomospira spp IRepmanina charoides, have been traditionally Interpreted as a result of dissolution of calcareous-shelled species. We carried out a thorough bibliographic revision of the post-extinction assemblages In widely distributed land-based sections and marine cores to: 1) document the paleogeographical extent on the so-called "Glomospira acme," 2) compare the characteristics among sites where the acme is present, and 3) assess the paleoenvironmental conditions that could have potentially controlled the occurrence of the Glomospira acme. We recognized the early Eocene (calcareous plankton biozones NP9 and P5) Glomospira acme in the Tethys and along the eastern margin of the North Atlantic Ocean. The comparison of the sedimentological and paleoenvironmental evolution across the PETM in these areas led us to conclude that the proliferation of Glomospira spp.IR. charoides may have been related not only to CaCO3 dissolution, but also to the pulsed input of siliciclastic material resulting from continental erosion or gravitational fluxes. Increased terrestrial runoff in nearshore-marine sediments is consistent with an enhanced hydrological regime or higher seasonality or episodicity, as previously proposed for the PETM, and with the paleogeographical distribution of the continental margins and slopes In the Tethys and northeast Atlantic region, where the Glomospira acme has been recorded. As a result of the increased siliciclastic Input, low-quality refractory organic matter would be transported to the seafloor, allowing the rapid proliferation of Glomospira spp.IR charoides.
Year of Publication: 2013
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Atlantic Ocean; Benthic taxa; Broken Ridge; Calcium carbonate; Cenozoic; DSDP Site 237; DSDP Site 328; DSDP Site 362; DSDP Site 400; DSDP Site 525; DSDP Site 553; DSDP Site 605; Deep Sea Drilling Project; East Pacific; Eocene; Equatorial Pacific; Foraminifera; Glomospira; Hudson Canyon; IPOD; Iberian abyssal plain; Indian Ocean; Invertebrata; Kerguelen Plateau; Leg 112; Leg 113; Leg 114; Leg 120; Leg 121; Leg 149; Leg 198; Leg 199; Leg 24; Leg 36; Leg 40; Leg 48; Leg 74; Leg 81; Leg 93; Lower Eocene; Marine environment; Maud Rise; Microfossils; North Atlantic; North Pacific; Northeast Atlantic; Northeast Pacific; Northwest Pacific; ODP Site 1209; ODP Site 1220; ODP Site 688; ODP Site 690; ODP Site 702; ODP Site 748; ODP Site 752; ODP Site 897; Ocean Drilling Program; Pacific Ocean; Paleocene-Eocene Thermal Maximum; Paleoecology; Paleoenvironment; Paleogene; Protista; Repmanina charoides; Rockall Plateau; Shatsky Rise; Solution; South Atlantic; South Pacific; Southeast Pacific; Southern Ocean; Tertiary; Walvis Ridge; Weddell Sea; West Pacific
Coordinates: S113216 S113215 W0785634 W0785635
S582627 S582627 E0785854 E0785853
N323900 N324000 E1583100 E1583000
N560519 N560520 W0232036 W0232037
Record ID: 2013018357
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Abstract, Copyright, Cushman Foundation for Foraminiferal Research, Reference includes data from GeoScienceWorld, Alexandria, VA, United States