Thermal-maturation,-potential-source-rocks-and-hydrocarbon-generation-in-Mesozoic-rocks,-Lougheed-Island-area,-Central-Canadian-Arctic-archipelago_1996_Marine-and-Petroleum-Geology.pdf

Marine ard Petrahnz Geoloy~, Vol. 13. No. 8, pp. 879-905. 1996
Copyright IC 1996 Elsevier Science Ltd
Printed in Great Britain. All rights reserved
PII: S0264-6172(96)00026-1 0264-8171196 $+
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Thermal maturation, potential source rocks and
hydrocarbon generation in Mesozoic rocks,
Lougheed Island area, Central Canadian Arctic
archipelago
Thomas Gentzis,* Fariborz Goodarzit and Ashton F. Embryt
*Alberta Research Council, Environmental Technologies, . Box 8330, Edmonton,
Alberta, T6H 5X2, Canada; tGeologica/ Survey of Canada, Institute of Sedimentary and
Petroleum Geology, 3303-33rd Street, N. W., Calgary, Alberta, TZL 2A7, Canada
Received 8 July 1995; revised 21 March 1996; accepted 21 April 1996
Significant oil and gas accumulations occur in and around Lougheed Island, Arctic Canada, where
hydrocarbon prospectivity is controlled by potential source rock distribution position.
The Middle to Upper Triassic rocks of the Schei Point Group (. Murray Harbour and Hoyle
Bay formations) contain a mixture of Types I and anic matter (Tasmanales marine algae,
amorphous fluorescing bituminite). These source rocks are within the oil generation zone and
have HI values up to 600 mg HC/g Corg. The younger source rocks of the Lower Jurassic Jameson
Bay and the Upper Jurassic Ringnes formations contain mainly gas-prone Type ll/anic
matter and are marginally mature. Vitrinite reflectance profiles suggest an effective geothermal
gradient essentially similar to the present-day gradient (20 to BO”C/km). Maturation gradients are
low, ranging from to log%Ro/km. Increases in subsidence rate in the Early Cretaceous
suggest that the actual heat flow history was variable and has probably diminished from that
time. The high deposition rates of the Christopher Formation shales coincide with the main phase
of rifting in Aptian-Albian times. Uplift and increased sediment supply in the Maas