Constraints on the timing of thrusting during the Eurekan orogeny, Canadian Arctic Archipelago: an integrated approach to thermal history analysis

Abstract

Thermochronological constraints on the timing of hanging-wall cooling across thrust faults can be interpreted in terms of fault movement under certain circumstances. Vitrinite reflectance data can be used to identify those circumstances and, in addition, provide constraints on the timing of fault movement relative to maximum paleotemperatures in the strata offset by faulting. Geological constraints and apatite fission track data from across the Vesle Fiord Thrust, Ellesmere Island, Canadian Arctic Archipelago, indicate that the initiation of fault movement occurred during the Paleocene, slightly older than predicted by plate-reconstruction models for compression during the Tertiary Eurekan orogeny, but in agreement with stratigraphic evidence for the onset of tectonism in the Sverdrup Basin. Vitrinite reflectance and fission track data further indicate that the strata affected by faulting attained their maximum paleotemperatures prior to deformation. The latter conclusion has important implications for hydrocarbon exploration at shallow levels in structural traps formed during the Eurekan orogeny.