The galo basin evolution model described
in Makhous et al. (1997) is applied to evaluate hydrocarbon generation
and migration histories in several Saharan basins. Three basins, the Oued
el-Mya, Ghadames, and Illizi, are located in the central and eastern parts
of the Saharan platform and are investigated in detail. The Ahnet, Mouydir,
Timimoun, Reggane, and other basins located in the southern and western
parts of the platform are also studied. The modeling results, combined
with geochemical data, are used in a synthesis of the regional framework.
The thermal gradients in the Ghadames and
Illizi basins are greater than those in the Oued el-Mya basin. This difference
is attributed to differences in sedimentation and subsidence rates, to
less Hercynian erosion, and to fewer occurrences of evaporates in the Akfadou
region of the Ghadames basin and in the Mereksen region of the Illizi basin.
In the southern and western parts of the Illizi province, the major subsidence
occurred before Hercynian uplift. Very moderate Hercynian uplift in the
Ghadames and Illizi basins did not involve a significant decrease of temperatures,
and organic matter maturation continued,
1997. The American Association of Petroleum Geologists. All rights reserved.
received July 24, 1995; revised manuscript received November 7, 1996; final
acceptance June 4, 1997.
State University, Geology Faculty, Department of Petroleum Geology and
Geochemistry, 119899, Moscow, Russia.
State University, Geology Museum, 119899, Moscow, Russia.
Institute, Russian Academy of Science, Varshavskoye Shosse 8, 113105, Moscow,
Makhous wishes to thank N. Zouaouche, Sonatrach's former vice-president,
and A. Belhaouas, director of Sonatrach's Center of Research and Development,
for their encouragement to conduct geochemical and lithological research
on Saharan basins.
thank former Elected Editor Kevin T. Biddle for his suggestions and guidelines
for improving the manuscript. We are indebted to A. E. Bence, who carefully
reviewed the manuscript, revised the text, and provided many helpful suggestions.
We are grateful to reviewers Roger Marzi, James A. Peterson, and Jim Clark
for many helpful comments and improvements to the text. Olga Simonenkova
is acknowledged for printing assistance.