712 research outputs found
“Heinrich events” (& sediments): A history of terminology and recommendations for future usage
IF/01500/2014info:eu-repo/semantics/publishedVersio
Data report: early Pleistocene calcareous nannofossils, IODP Expedition 339, Site U1387
We present a revision and refinement of semiquantitative analyses of calcareous nannofossil assemblages in early Pleistocene
samples from Holes U1387A and U1387C recovered toward the
eastern end of the Faro Drift (36°48.3210N, 7°43.1321W) during
Integrated Ocean Drilling Program Expedition 339, Mediterranean Outflow (November 2011–January 2012). The record is characterized by intervals very rich in calcareous nannofossils that
are in general moderately to well preserved. On the other hand,
the record contains an interval directly above the youngest dolomite layer in Section 339-U1387C-19R-4 (~0.7 m) where no coccoliths were preserved. The new stratigraphic constraints of
events such as the lowest occurrence (LO) of large Gephyrocapsa,
the highest occurrence (HO) of Calcidiscus macintyrei (1.66 Ma),
the LO of medium-sized Gephyrocapsa group, and the HO of Discoaster brouweri (1.95 Ma) allow better interpretation of the isotope stratigraphy applied to this interval.FCT Portugal projects CCMAR:UID/Multi/04326/2019info:eu-repo/semantics/publishedVersio
Deep water properties in the North Atlantic's eastern and western basins during the Mid-Brunhes (330-630 ka)
European Geosciences Union General Assembly 2009 (EGU 2009), Vienna, Austria, April 19-24,
200
Planktonic foraminifera evidence for surface-water conditions off Southern Portugal during Mid-Pleistocene marine isotope stages 20 to 24 (790 – 940 ky)
Characterized by a drastic change in the deep thermohaline circulation, the Mid Pleistocene Transition (MPT) was a global
climatic event resulted in more intense and longer lasting glacial periods and cooler sea
-surface temperatures. The present study's
objective is characterized surface
-water variations during the MPT interval at the mid
-latitude southern Portuguese margin using
planktonic foraminifera faunal data from Site U1387. Stratigraphy records reveals dominantly tropical and subtropical species
interrupted by incursions of subpolar waters when the North Atlantic's subarctic front moved to southernmost position during the
MPT.info:eu-repo/semantics/publishedVersio
Mediterranean outflow conditions during the early to middle Pleistocene linked to precession forcing
The Mediterranean Outflow Water (MOW) is an important intermediate depth water mass in the North Atlantic. Here we
reconstruct changes in the MOW during the early Pleistocene interval from 630 to 1760 ky, encompassing the Mid-Pleistocene
Transition (MPT), which marks an important change in orbital climate forcing. Neither MOW ventilation nor MOW flow strength
reveal changes related to the MPT, but incorporate variations related to precession (insolation) forcing. The MPT related change
to higher glacial benthic δ O values occurs earlier at Site U1387 than in most deep-sea records, i.e. with MIS 26 instead of the
MIS 24 to MIS 22 intervalThis study was supported by FCT through projects CCMAR (UID/Multi/04326/2019) and MOWCADYN (PTDC/MAR-PRO/3761/2012)info:eu-repo/semantics/publishedVersio
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