STRUCTURAL DIVISION OF MARINE MESOZOIC-PALEOZOIC IN LOWER YANGTZE REGION AND ITS SIGNIFICANCE FOR PETROLEUM EXPLORATION TARGETS

According to the basement features, structural deformation, depth of the Indo-surface and characteristics of depocenters and subsidence centers, the Lower Yangtze region has been divided into 5 first-order geological structure zones and 17 second-order zones mainly In terms of structural stability, effective preservation, and late-stage hydrocarbon generation, the second-order zones have been assessed.The Lower Paleozoic favorable zones for exploration include the late-stage uplifting stable region in centeral part of southern Yellow Sea (Ⅰ₂), the late-stage subsiding deep thrust region in Jiangdu-Dongtai-southern part of the South Yellow Sea (Ⅰ₃), the late-stage subsiding deep thrust region in Taixing-Haian (Ⅱ₁), the late-stage subsiding lower nappe region in Nantong-south part of South Yellow Sea (Ⅱ₂), and the late-stage subsiding lower nappe region around the Taihu Lake (Ⅱ₄); the Upper Paleozoic favorable zones for exploration include, the latestage subsiding deep thrust region in North Yellow Sea (Ⅰ₁), the late-stage subsiding deep thrust region in Jiangdu-Dongtai-south part of South Yellow Sea, (Ⅰ₃), the late-stage subsiding deep Lower Paleozoic-involved thrust region in Binhai-Dafeng (Ⅰ₄), the late-stage subsiding deep thrust region in Taixing-Haian (Ⅱ₁); the most favorable zones for Indo-surface exploration include the late-stage subsiding deep thrust region in North Yellow Sea (Ⅰ₁), the late-stage subsiding deep Lower Paleozoic-involved thrust region in Binhai-Dafeng (Ⅰ₄), the late-stage subsiding deep Lower Paleozoic-involved thrust region in Jinhu-Gaoyou (Ⅰ₅), and the late-stage subsiding deep thrust region in Taixing-Haian (Ⅱ₁).