A Classification of Meso-Cenozoic Continental Basins and Their Oil-Gas Pontentials in China
WU CHANGLIN, Louisiana State University, Baton Rouge, LA, and XUE SHUHAO, Research Institute of Petroleum Exploration, Beijing, China
Most of the oilfields in China are located in Mesozoic-Cenozoic continental basins. Characteristics of continental sediments are controlled by such factors as palaeoclimatic zones, distance from oceans, paleogeomorphic features, and tectonic settings.
Based on palaeoclimatic zonation, the continental basins in China can be divided into humid, arid, and humid-arid transitional types. Furthermore, based on the distances from oceans, they can be classified into inland and onshore types, and based on regional geomorphic features, they can be classified into faulted and depressional types. According to three factors, the Mesozoic-Cenozoic continental petroliferous basins in China can be grouped under ten types as follows: (1) onshore humid faulted type such as Zhujiangkou (Pearl River Mouth; E); (2) onshore humid depressional type such as Songliao (K); (3) inland humid faulted type such as Baise (E); (4) inland humid depressional type such as Ordos (T); (5) onshore arid-humid faulted type such as Bohai Bay (E); (6) inland arid-humid fau ted type such as Jiuxi (K); (7) inland arid-humid depressional type such as Junggar (E); (8) onshore arid depressional type such as Tarim (E); (9) inland arid faulted type such as Jianghan (E); and (10) inland arid depressional type such as Tsaidam (E-N).
Sedimentary systems in different basins have different depositional characteristics and petroliferous potentials. Sedimentary systems in humid depressional basins are often characterized by major rivers along the long axis where alluvial plains were extensive and deltas could be formed in shallow water areas. Humid faulted basins were favorable for development of pluvial fan--fan delta--lake sedimentary systems and pluvial fan--braided river--meandering river--delta--shallow lake sedimentary systems. In arid-humid transitional faulted basins were fan delta-dominated systems, pluvial turbidite-dominated systems, delta-dominated systems as well as coastal bar-beach and bioherm-dominated systems. Onshore basins in humid zone and arid-humid transitional zone have best petroleum prospects, and inland basins in humid and arid-humid transitional zones are second while the basins in arid zone are third.
AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)