Sedimentary characteristics and depositional model in the Sandbian-Early Katian Ages of Late Ordovician in Hunan area
Ge Xiangying1，2 Mou Chuanlong1，2 Zhou Kenken1，2 Liang Wei1，2
1 Key Laboratory for Sedimentary Basin and Oil and Gas Resources, Ministry of Land and Resources, Chengdu 610081, Sichuan; 2 Chengdu Institute of Geology and Mineral Resources, Chengdu 610081, Sichuan
Abstract：Hunan area is located between the Yangtze and Cathaysia Blocks.According to its petrologic characteristics，archeological features and other depositional features，this area can be divided into open carbonate platform，shallow marine shelf，deep-water basin and shelf-margin-slope facies in the Sandbian-Katian Ages of Late Ordovician. The open carbonate platform facies was characterized by the deposition of“chap-cracked”limestones and nodular limestones，while the shallow marine shelf deposited mainly sandy slate，slate with siltstone and marl interbeds.The deep-water basin was composed of black carbonaceous shale and radiolarian-bearing silicolites with thin thickness，which reflected a withlead，anoxic and uncompensated deep water environment.The shelf-margin-slope facies deposited lithic quartz silt-fine sandstone，feldspar quartz silt-fine sandstone with slate interbeds，which showed typical features of turbidite deposits with more than kilometers sedimentary thickness. The water was increasing gradually in the central Hunan area(from northwestern to southeastern)during the Sandbian-Early Katian Ages of Late Ordovician，and the southern-central Hunan area was the deepest area.
Ge Xiangying,Mou Chuanlong,Zhou Kenken et al. Sedimentary characteristics and depositional model in the Sandbian-Early Katian Ages of Late Ordovician in Hunan area[J]. JOPC, 2013, 15(1): 59-68.
