Sedimentologic and Cyclo- and Sequence-Stratigraphic Analyses of Fluvial-Lacustrine Fills in Intracontinental Rift Basins, NW China
Jonathan Obrist-Farner* and Wan Yang
Missouri University of Science and Technology, Department of Geological Science and Engineering Rolla, Missouri, U.S.A.
The Turpan-Junggar Basin in NW China contains various complete petroleum systems and has been a target for extensive petroleum exploration and exploitation. However, the complexity of the basin fill, with common erosional surfaces, lateral and regional thickness changes, and a poor to non-existent biostratigraphy has hampered stratigraphic correlation. The research focuses on the sedimentology and stratigraphy of mid-Permian (Capitanian) fluvial-lacustrine-eolian(?) deposits of the Quanzijie (QZJ) Formation exposed in the Bogda Mountains to develop an effective strategy of nonmarine cyclo- and sequence-stratigraphic analysis. These superbly-exposed strata offer a unique opportunity to interpret the processes and factors controlling basin filling, such as tectonics, climate, provenance, and conditions of the catchment basin. The study will provide an analog of depositional systems and stratigraphic architecture to the subsurface and aid in ongoing petroleum exploration.
Ten stratigraphic sections of the QZJ Formation have been measured in the Bogda Mountains to identify regional stratigraphic variations. The sections have been successfully correlated at a low-order cycle scale. However, regionally, lateral and vertical stratigraphic changes in lithology and thickness hamper intra- and inter-graben stratigraphic correlation at a high-order cycle scale. Petrographic, geochemical, outcrop data and 2-D seismic data will be used to understand the roles of provenance, tectonics, climate and depositional processes in the deposition of QZJ sediments and to reconstruct the QZJ stratigraphic architecture. Finally, the strategies developed to establish a stratigraphic architecture in nonmarine deposits will be used as an analog to the subsurface of the Turpan-Junggar Basin and other similar basins around the world.
AAPG Search and Discovery Article #90157©2012 AAPG Foundation 2012 Grants-in-Aid Projects