关键词: 渤海湾, 文留构造, 盐构造运动, 次动盐刺穿, 物理模拟, 构造地质学

Abstract: The Wenliu salt structure is localized above the central uplift in the northeast part of the Dongpu depression,Bohai Bay basin.The structure comprises downwards a simple crestal graben,a thickened salt core,and a basement horst.The structure was formed during the early of sha 3,stage of Eogene thick skinned extension.At an early stage,the salt layer partially decoupled deformation above and below the salt.The overburden formed forced fold that was cored with salt pillow above the central basement horst block.A graben formed at the crest of the forced anticline due to local arching.By the combination of regional extension and local stretching,the crestal graben widened and triggered reactive diapirism.Synkinematic sediments in the flank depressions caused salt to flow upward to the central basement uplift,which enhanced the rise of the Wenliu reactive salt diapir.As regional extension decreased,the reactive diapir ceased to rise and was buried by the Neogene and Quaternary sediments. We used scaled physical models of basement involved salt tectonics and salt dissolution to simulate the development of the Wenliu structure.The experiments reproduced the dynamic evolution of the Wenliu structure by regional,thick skinned extension.Conversely,salt dissolution had negligible influence on the formation of the simple Wenliu graben.

Key words: Bohai Bay, Wenliu seruceure, salt structure, reactive, diapir, sealed physical modeling, structural geology