Abstract:

  Recent researches on the submarine canyon and the marine gas hydrate indicated that they had the similar spatial distribution. Moreover, because of the erosion and internal architecture, submarine canyons showed the good relationship with the accumulation and distribution of marine gas hydrates. Based on the integrated analysis of studies in the past decade, the correlations between canyons and hydrates could be summarized as three points, i.e.erosion and sedimentation of canyons controlling the distribution of deposits favorable for hydrate, potential leak mechanism between submarine canyons and hydrocarbon-bearing fluid release, and the dynamic accumulation of gas hydrates influenced by submarine canyons. The correlations were used in the submarine canyons in the Pearl River Mouth Basin. On the one hand, these canyons could erode the favorable deposits and further influence the distribution of gas hydrates, and on the other hand, due to the erosion and sedimentation of canyons, the pre-existing hydrates might be dissociated. Impeded by the fine-grained homogeneous layer, most of the dissociated gases would be restricted in the favorable deposits and form the new hydrates, which could be used to help understanding the relatively high saturation of gas hydrate in the fine-grained sediments in the Shenhu Area, northern South China Sea.

Key words: submarine canyon, erosion and sedimentation, gas hydrate, accumulation mechanism