Emma Sheldon

Palaeogene nannofossil biostratigraphy of the Kangâmiut-1 and Nukik-2 wells, offshore West Greenland

A new Palaeogene nannofossil study has been made of the Kangâmiut-1 and Nukik-2 wells, offshore West Greenland. The stratigraphy presented herein has been correlated with previously established nannofossil zonation schemes and where possible used to indicate palaeoenvironmental changes during the Early and Middle Eocene. The stratigraphy and dating is based upon stratigraphically important species and palaeoenvironmental signals are based upon species influxes. A total of 69 samples (26 side wall cores and 43 ditch cuttings samples) were examined and where possible, were compared with findings from DSDP and ODP sites in the Labrador Sea.

Microfossil biostratigraphy of the Palaeogene succession in the Davis Strait, offshore West Greenland

Abstract A new microfossil based biostratigraphy of the Paleocene and Lower Eocene sediments of the Hellefisk-1, Ikermiut-1, Kangâmiut-1, Nukik-1, and Nukik-2 boreholes offshore West Greenland has been established. In general, the five boreholes contain fairly well-preserved, diverse microfossil faunas and floras consisting mainly of foraminifera, radiolaria, ostracods and diatoms. The studied interval was subdivided into three foraminiferid biostratigraphic intervals, in ascending stratigraphic order, the Stensioeina beccariiformis , Praeglobobulimina ovata and Pseudohastigerina wilcoxensis intervals and five biostratigraphic intervals based on additional microfossil groups (the Thalassiosiropsis wittiana , Fenestrella antiqua–Coscinodiscus morsianus , Ostracod, Aulacodiscus hirtus and Cenodiscus–Cenosphaera intervals). The intervals are more easily recognised in the two basinal boreholes, Ikermiut-1 and Kangâmiut-1, than in the three more nearshore boreholes, Nukik-1, Nukik-2 and Hellefisk-1, due to a higher microfossil diversity and abundance.

Late Maastrichtian foraminiferal response to sea-level change and organic flux, Central Graben area, Danish North Sea

Abstract Foraminiferal palaeoecological analyses were carried out on 124 upper Maastrichtian chalk samples from the M-10X and E-5X wells of the Danish Central Graben. The two wells demonstrate similar trends, with some notable differences. Both are strongly dominated by planktic foraminifers, of which the small, biserial Heterohelix globulosa is by far the most common species. Based on variations within five significant, benthic foraminiferal morphogroups and the plankton/benthos ratio, eight specific foraminiferal intervals have been described. The faunal and palaeoenvironmental changes observed during the late Maastrichtian period were, in most places and especially in the lower part, not very distinct, and it is believed that the palaeoenvironment during the majority of the interval was a mostly stable, deep outer-shelf environment characterized mainly by pelagic sedimentation under temperate, suboxic conditions. More unstable conditions characterized the latest Maastrichtian. The analyses show that the sediments in the M-10X well were deposited in a generally deeper palaeoenvironment than those from E-5X. The influx of common Pseudotextularia elegans (three acmes), together with scattered specimens of the typical Tethyan species Abathomphalus mayaroensis and Pseudoguembelina hariaensis (in E-5X only), indicate that relatively warm conditions prevailed, at least periodically, during the latest part of the late Maastrichtian in both areas.