FACTORS CONTROLLING GAS HYDRATE ACCUMULATION IN MAKRAN ACCRETIONARY WEDGE OFF PAKISTAN

A large number of documents and references are reviewed for revealing the main controlling factors of gas hydrate accumulation in the Makran accretionary wedge. It is found that the activity of thrust faults in the Makran accretionary wedge is gradually weakened from west to east and from south to north, together with the weakening of the amplitude and continuity of BSR. The occurrence of BSR is obviously controlled by faults. The Makran accretionary wedge is characterized by large thickness, shallow SMI interface, bubble structure of hydrate samples and thick free gas under BSR, indicating that there is sufficient gas source for gas hydrate to form. At the same time, the northward Arabia Plate Subduction at a low angle created a series of E-W aligned and parallel thrust faults and some small normal faults, that may provide migration pathways for deeper natural gas to move upwards. It is then concluded that tectonic action and fault activities are the main controlling factors for gas hydrate to accumulate in the Makran accretionary wedge