GAS HYDRATE ACCUMULATION CONDITIONS AND MECHANISM ON THE SOUTH SHETLAND CONTINENTAL MARGIN, ANTARCTIC PENINSULA

The South Shetland Continental Margin is a typically active continental margin. The system of trench-accretionary wedge-forearc basin is well developed, which creates favorable geological and structural background for gas hydrate accumulation. The Survey data shows that this region has significant signs of gas hydrates, such as the occurrence of the Bottom Simulating Reflector(BSR)and polarity reversal characteristics (or the Base of Gas Reflector, BGR). There are plenty of gas sources, stability regions, depositional systems and specific tectonic environment suitable for gas hydrate formation and accumulation. They fit well with the geological model of hydrate reservoir formation under the control of tectonics. The methane within the accretionary wedge moving upward together with fluids plays important roles.