Salt removal and sedimentation in Southern Oman

Publisher Website
Google Scholar
Abstract
On the Eastern Flank of the South Oman Salt Basin lies a Cambrian to Recent sequence much affected by the withdrawal and dissolution of underlying Infracambrian salt. Salt withdrawal began after burial by only a few hundreds of metres of Cambrian continental sands, and salt dissolution has taken place periodically up to the present, initially near-surface and later in the subsurface. Salt removal has (1) resulted in the collapse of masses of dolomite and shale formerly interbedded with the salt, (2) influenced the large-scale geometries of sedimentary bodies within the overlying succession, (3) affected the distribution of sedimentary facies when rates of salt removal balanced or exceeded sedimentation, (4) allowed the preservation of parts of the succession otherwise eroded at this basin margin, and (5) caused folding and fracturing of Cambrian to Recent sediments.More than 2 × 109m3of oil (12 × 109bbls) is estimated to be present in four types of hydrocarbon trap related to salt removal. In terms of importance these are: large turtleback anticlines resulting from the inversion of former peripheral synclines, truncation traps rimming eroded turtle-back anticlines, small anticlines draped over residual masses of dolomite and shale, and porous and fractured dolomites within such residual masses.Comparison of salt removal phenomena from the Eastern Flank of the South Oman Salt Basin, the North Sea, western Canada and the USA suggests that the south Oman features may be typical of the margins of basins where a thick mobile salt sequence is overlain by clastic sediments.