Thermochronometric Investigation of Multiple Unconformities and Post-Depositional Thermal History of a Fault Block in the Northern Western Desert, Egypt
Travis Robert Glauser
University of Kansas, Dept. of Geology Lawrence, Kansas 66045; [email protected]
Low-temperature thermochronometry is a powerful tool to constrain the thermal evolution and hydrocarbon maturation history of sedimentary basins. Quantitative interpretation of thermochronometric data from cuttings of core material from boreholes can be used to elucidate the thermal evolution of rocks and to constrain the timing and magnitude of stratigraphic omission associated with the formation of major unconformities and faulting. The subsurface of the Western Desert of Egypt is an ideal case study as it contains multiple stacked sedimentary basin deposits separated by major unconformities, reflecting the long-lived evolution of the Neothyan continental margin in eastern North Africa. It is characterized by major erosional unconformities excising upper Paleozoic and lower Mesozoic stratigraphic record normally present in the regional stratigraphy. The timing of erosional removal of source and reservoir rocks with respect to the timing of hydrocarbon maturation is crucial for the understanding of this hydrocarbon system. In this study, zircon (U-Th/He) data obtained from borehole cuttings coupled with numerical modeling will quantitatively establish a thermal history of the stratigraphic section and elucidate the timing and magnitude of erosion. Newly developed numerical code will incorporate the development of unconformity to elucidate the temporal relationship of these unconformities to Jurassic rifting and Early Cretaceous reactivation. The numerical code will not only allow quantification of the thermal evolution and hydrocarbon maturation in the Western Desert region, but create new numerical tools for the interpretation of integrated multi-sample down-hole zircon and apatite (U-Th)/He thermochronometric data.
AAPG Search and Discovery Article #90083 © 2008 AAPG Foundation Grants in Aid