An Integrated Approach to Investigating Thermal Histories in Fold and Thrust Belts - an Example from the Sverdrup Basin, Canada: ABSTRACT

Abstract

The interpretation of thermal histories in fold and thrust belts is complicated by a variety of factors, such as overthrusting, groundwater recharge and uplift of rocks in response to regional isostatic adjustments. The timing of these events with respect to the formation of structural traps has important implications for hydrocarbon charge models in deformed terranes. Vitrinite reflectance (R[sub 0]) data can be used to determine the timing of structures relative to peak temperatures, whereas apatite fission-track analysis (AFTA) data can be used to determine the absolute time of cooling. Evidence of differential cooling across thrust faults can be used to constrain the timing of fault movement if it is assumed that cooling was due to exhumation. The Sverdrup Basin of the Canadian Arctic Archipelago is an intracratonic rift basin initiated during the late Paleozoic. Compression of the Sverdrup Basin occurred during the early to mid-Tertiary Eurekan Orogeny. Thermal maturity data from the Sawtooth Range, Fosheim Peninsula indicate that thrusting post-dated maximum temperatures in the Mesozoic to Cenozoic sequence affected by deformation. Preliminary AFTA data from the hangingwall of the Vesle Fiord Thrust Fault suggest an Eocene time of thrusting, consistent with geological and geophysical constraints on the timing of themore » Eurekan Orogeny. Additional AFTA data from nearby petroleum exploration wells reveal kilometer-scale exhumation on broad, regional anticlines during the Tertiary, as well as considerable erosion off-structure. These data suggest that maximum temperatures preceded the formation of structural traps during the Eurekan Orogeny.« less