Welcome to the Tarlong Valley Blog!
The theme of this blog pertains to my ongoing thesis research of cyclic Permian fluvial and lacustrine deposits of NW China. The focus of the research is reconstructing stratigraphic architecture and basin-fill history of nonmarine deposits in a half-graben. The location of study is in the beautiful and remote Tarlong Valley, in the southern foothills of the Bogda Mountains, Xinjiang, NW China.
I am currently focusing on the nature and origins of a nonmarine cycle boundary in a half-graben. A nonmarine stratigraphic boundary where major facies shifts occur indicates drastic changes in environmental conditions, but may have highly variable magnitude of facies shifts in different parts of a half-graben due to rapid lateral facies changes, common autogenic processes, and irregular topography. This hypothesis is tested using the boundary separating lower Permian Lucaogou and Hongyanchi low-order cycles in Tarlong-Taodonggou half graben, which covers 88 km2. Superbly exposed sections were measured in the summer of 2009 of the boundary. The boundary shows variable facies juxtapositions on 5 sections 0.2-5 km apart. Complex facies relationships in the NE signify the control by local fluvial valley topography. Understanding autogenic and allogenic processes and basin topography is critical to correlating stratigraphic boundaries in n onmarine time-stratigraphic analysis.
