Michael E. Brookfield1
(1) University of Guelph, Guelph, ON
Abstract: Geology and petroleum of the North Afghan Platform and adjacent areas (northern Afghanistan, with parts of southern Turkmenistan, Uzbekistan and Tajikistan)
The North Afghan platform has a pre-Jurassic basement overlain by a Jurassic to Paleogene oil- and gas-bearing sedimentary rift to platform cover, unconformably overlain by Neogene syn- and post-orogenic continental clastics.
The Mesozoic-Paleogene cover has: a variable ?Late Triassic to Middle Jurassic coal-bearing rift succession which is the main hydrocarbon source; a fairly uniform Middle Jurassic to Upper Cretaceous mixed continental and marine succession which has the main reservoirs, sealed by Upper Jurassic salt and Upper Cretaceous shales; a thin, uniform Paleogene succession with minor reservoirs, and a very variable Neogene succession of coarse continental clastics.
Almost all the hydrocarbon traps are in limestones and sandstones within broad anticlines related to Neogene wrench faulting (like those along the San Andreas fault). The North Afghan platform is gas-prone. Hydrocarbon sources are dominated by the Jurassic coal-bearing beds which provide about 75% of the hydrocarbons.
Further studies should be rewarding because the strike-slip traps are difficult to find without detailed exploration; the instability of the last twenty years has prevented exploration; and conditions may soon become more favorable for exploration. There is potential for oil, and particularly gas, discoveries in the northern and western parts of the platform.
AAPG Search and Discovery Article #90914©2000 AAPG Annual Convention, New Orleans, Louisiana