Lower Cretaceous Prograding Units in the eastern part of the SW Barents Sea

• Main Author: Dimitriou, Myrsini
• Format: Master Thesis
• Language: English
• Published: 2014
• Subjects: SW; Barents; Sea; Lower; Cretaceous; prograding; units; Arctic; Barents Sea; Franz Josef Land; Helvetiafjellet; Svalbard
• Online Access: http://hdl.handle.net/10852/42303; http://urn.nb.no/URN:NBN:no-46690

A large-scale 2D seismic sequence analysis of the Lower Cretaceous successions in the eastern part of the south-western Barents Sea is presented. Well and shallow borehole data are used to further constrain and assist the interpretation. Four distinct prograding units are recognized and mapped, each characterized by internal, low-angle clinoforms. They are bounded by a maximum flooding surface at the base and an erosional truncation on top; both types of sequence boundaries are correlated over the entire area. The lap-out points and the space relationship between the different clinothem packages was mapped. A regional depositional model was developed through the integration of the available data. The interplay between local, regional and supra-regional events was discussed in connection with the unit s depositional history. In the Early Cretaceous, the eastern part of the south-western Barents Sea was a relatively shallow epicontinental sea, located within the Boreal Basin. It was gradually filled-in during four phases, with two major progradational directions; NW to SE and NE to SW; the latter being the dominant direction. The sediments were sourced from a location north of the northern margin of the present-day Barents shelf; an uplifted area associated with the rising High Arctic Large Igneous Province (HALIP). The clinoform system is connected with the fluvial/paralic system of the Helvetiafjellet Formation on Svalbard, and its likely time equivalent chronostratigraphic units on Franz Josef Land, as the southward continuation of its drainage system. A direct tie between the two systems, within the Norwegian sector, is not possible, due to Cenozoic uplift and erosion. Mantle processes, related to the HALIP, are suggested to account for the creation of accommodation. A widespread condensed carbonate succession of Valanginian to early Barremian age constitutes the downlapping surface, with the clastic deposits being of early to middle Barremian age, according to well and shallow borehole data.