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Insights from the Paleogene tropical Pacific: Foramineral stable isotope and elemental results from Site 1209, Shatsky Rise

Dutton, Andrea; Lohmann, K; Leckie, R M

Description

Stable isotope and elemental measurements were conducted on foraminifera from a sequence of calcareous pelagic ooze at Ocean Drilling Program Site 1209 to document the thermal evolution of the North Pacific water column over Shatsky Rise and to address long-standing questions about the nature of oceanic circulation in the early Paleogene. A major change in seasonality and water column structure in the early Eocene marks a change in tropical Pacific climate and circulation just prior to the...[Show more]

dc.contributor.authorDutton, Andrea
dc.contributor.authorLohmann, K
dc.contributor.authorLeckie, R M
dc.date.accessioned2015-12-13T22:59:39Z
dc.identifier.issn0883-8305
dc.identifier.urihttp://hdl.handle.net/1885/83912
dc.description.abstractStable isotope and elemental measurements were conducted on foraminifera from a sequence of calcareous pelagic ooze at Ocean Drilling Program Site 1209 to document the thermal evolution of the North Pacific water column over Shatsky Rise and to address long-standing questions about the nature of oceanic circulation in the early Paleogene. A major change in seasonality and water column structure in the early Eocene marks a change in tropical Pacific climate and circulation just prior to the early Eocene climatic optimum. Subsequent long-term cooling is interrupted by a transient positive δ18O excursion identified in planktonic and benthic foraminifera during the late early Eocene that is interpreted as evidence for ephemeral formation of deep water from a low-latitude, saline source. Paired analysis of benthic Mg/ Ca and δ18O was undertaken to assess the relative contribution of temperature and seawater oxygen isotope composition to the benthic δ18O record. Stratigraphic trends of benthic δ18O and Mg/Ca decouple during two intervals in the early Eocene and early middle Eocene. Although variable seawater δ18O is the most likely candidate to explain decoupling of benthic δ18O and Mg/Ca, it is difficult to argue for substantial change in continental ice volume during a presumably ice-free interval of time.
dc.publisherAmerican Geophysical Union
dc.sourcePaleoceanography
dc.subjectKeywords: foraminifera; Ocean Drilling Program; oxygen isotope; paleoceanography; Paleogene; oceanic regions; Pacific Ocean; Shatsky Rise; World; Foraminifera
dc.titleInsights from the Paleogene tropical Pacific: Foramineral stable isotope and elemental results from Site 1209, Shatsky Rise
dc.typeJournal article
local.description.notesImported from ARIES
local.description.refereedYes
local.identifier.citationvolume20
dc.date.issued2005
local.identifier.absfor040399 - Geology not elsewhere classified
local.identifier.ariespublicationMigratedxPub12186
local.type.statusPublished Version
local.contributor.affiliationDutton, Andrea, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationLohmann, K, University of Michigan
local.contributor.affiliationLeckie, R M, University of Massachusetts
local.description.embargo2037-12-31
local.bibliographicCitation.startpage1
local.bibliographicCitation.lastpage16
local.identifier.doi10.1029/2004PA001098
dc.date.updated2015-12-12T07:29:53Z
local.identifier.scopusID2-s2.0-27744526378
CollectionsANU Research Publications

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