Paleogene sedimentation in Central Basin of Svalbard - Depositional conditions, geochemical and mineralogical variations across PETM

Abstract

This study deals with the recunstruction of depositional environments and development of transgressive-regressive sequences within the upper Grumantbyen Formation and lower Frysjaodden Formation in the Central Basin. Data from sedimentary field logging, XRD and geochemical analysis has been integrated to elucidate the depositional environments.Emphasis has been laid on use of clay mineralogy as proxy for peleoclimate conditions, especially PETM: The most pronounced climatic anomaly of the Cenozoic era.

In the studied sections, deepnig upwards developments have been identified from the Grumantbyen Formation to lower Frysjaodden Formation. Two maximum flooding intervals have been identified the basal parts of Marstranderbreen Member and Gilsonryggen Member. Shallowing upward developents have also been noticed in the middle part of two cores containing Hollendardallen Member. The upper part of all cores display a transgressive development into homogenous laminated shales of Gilsonryggen Member.

PETM intervals have been identified in all three core just below and within the Maximum flooding intervals of basal Gilsonryggen Member. Kaolinite/(kaolinite+chlorite) and kaolinite/(kaolinite+chlorite) ratios forms the basis of PETM recognition and its stratigraphic position coincides earlier studies from Svalbard.