Investigation of the Burial and Exhumation History of East Greenland Based On Apatite-fission Track Analysis, Stratigraphic Landform Analysis and the Geological Record

Abstract

AbstractCenozoic uplift and erosion have an important impact on petroleum systems along East Greenland. We have undertaken a regional study of the thermo-tectonic development of the East Greenland margin (68-75°N) based on apatite fission-track analysis (AFTA) data and analysis of the large-scale landscapes. Our results reveal a long history of post-Palaeozoic burial and exhumation across the region. Following breakup at the Paleocene-Eocene transition, the margin underwent kilometerscale burial beneath a cover of Eocene basalts and sediments. Subsequently, three regional phases of uplift and exhumation subsequently shaped the present-day margin. A late Eocene phase of uplift led to formation of a regional erosion surface near sea level (the Upper Planation Surface, UPS). Uplift of the UPS in the late Miocene led to formation of the Lower Planation Surface (LPS) by incision below the uplifted UPS, and a Pliocene phase led to incision of valleys and fjords below the uplifted LPS, leaving mountain peaks reaching 3.7 km above sea level.Preliminary AFTA results from northern East Greenland indicate that the Eurekan Orogeny played a significant role in the thermotectonic development there, but it is difficult to distinguish between heating related to burial followed by erosion and heating caused by high heat flow or hydrothermal activity. A future study of northern East Greenland margin should thus investigate the development during the right-lateral, strike-slip tectonics that moved the Barents Sea relative to Greenland.The results are of importance in assessing the hydrocarbon prospectivity in the offshore basins because uplift and denudation of continental margins can have profound effects on the hydrocarbon system, not only through negative impact of processes but also by providing reservoir clastics to the offshore basin and by changing migration routes. Our results indicate that remnants of oil accumulations on Traill 0 are associated, not only with the deeper burial at the time of hydrocarbon formation, but also with locally increased heat flow from late Eocene intrusions. Further afield, in areas where heat flow was not enhanced, any source rocks present would have remained at lower maturity levels at the end of the Eocene.