Reworked Jurassic-Neogene calcareous nannofossils in the central Arctic

Ansvarlig organisasjon

1994 (engelsk)Inngår i: Marine Geology, Vol. 119, nr 3/4, s. 287-300Artikkel i tidsskrift (Fagfellevurdert)

Abstract [en]

Over 130 different reworked calcareous nannofossil taxa, ranging from the Lower Jurassic to the Neogene, are recorded in Quaternary sediments from the central Arctic Ocean. Species with Mesozoic and Tertiary stratigraphic ranges occur together. This suggests that the reworked specimens are not primarily derived from the local bedrock, but are transported to the central Arctic Ocean from the surrounding shelves and landmasses. Sea ice provides a possible means of transport. The reworked nannofossil assemblages in the Arctic are a result of geologic and climatic developments in the source areas, both during the time of their deposition and during their subsequent erosion and transportation in the Quaternary. Only two specimens restricted to the Lower Jurassic were observed and none restricted to the Middle and Upper Jurassic. The Lower Cretaceous is represented by at least four species restricted to that interval, together with other long ranging taxa. The presence of Micrantholithus speetonensis Perch-Nielsen is the first record of this species outside northwest Europe. The other Lower Cretaceous species observed are all typical of temperate to high latitude assemblages of both the southern and northern hemispheres. The nannofossils reworked from the Upper Cretaceous strata are the dominant component of the assemblages. Nephrolithus corystus Wind is recorded in the northern hemisphere for the first time. Some of the distinctive high latitude species present in the southern hemisphere have not been observed in the Arctic. Helioliths, discoasters and sphenoliths indicate relatively warm surface water conditions in the Arctic-subarctic areas during the Paleocene and Eocene.

sted, utgiver, år, opplag, sider

1994, 3 April 2003. Vol. 119, nr 3/4, s. 287-300

Emneord [en]

nannofossils, fossils, Arctic Ocean Expedition 1991, SWEDARCTIC 1991, Oden-91, Arctic, Arctic Ocean

Identifikatorer

URN: urn:nbn:se:polar:diva-520DOI: 10.1016/0025-3227(94)90186-4OAI: oai:DiVA.org:polar-520DiVA, id: diva2:568652

Merknad

Source: Polardok by Swedish Polar Research Secretariat

Tilgjengelig fra: 2012-11-15 Laget: 2012-11-15 Sist oppdatert: 2012-11-15

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