Abstract: A Proterozoic Intracontinental Rift System and its Hydrocarbon Prospects - Son Valley, Vindhyan Basin, India

PRATAP, MAHENDRA, DATTA DIPANKAR

The Upper Proterozoc Vindhyan basin of central India, which confirmed the presence of hydrocarbons with the first drilled well, was formed by strike-slip tension and rifting on a pre-existing rifted continental block (Son-Narmada mid-continental rift). The major transtensional faults, subparallel to the basinal strike along with few oblique extension fractures controlled the differential tilting and sagging of the subblocks within the basin. Periodic reactivation of the blocks and wrenching led to inversion along a few linear accommodation zones at the later phase of basin development.

The Vindhyan sea was very shallow restricted marine type. Local unconformities at different levels of stratigraphy reflect the mobility of basement during the basin's early history. The algal stromatolites within the shallow-water shelfal facies are contributing type-I kerogen but the overall source rock units show moderate to low concentration of organic carbon. Maturity profiles indicate that the best source rocks are reached at the dry gas stage. Hydrocarbon potential of the basin is moderate and the proposed areas are identified as: i) structural closures developed during different phases of reactivation, ii) stratigraphic and unconformity traps, iii) clastic wedges associated with local unconformities around the uplifted blocks.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria