| Yunnan Lufeng region located in the west edge of Yangtze paraplatform, which produces a large number of dinosaur fossils, is known as " the hometown of dinosaur "。Predecessors conducted a lot of paleontology research work in the region, how-ever, the region research of Jurassic sedimentary facies and detailed sequence strati-graphy and analyse of basin evolution is still insufficient In this paper based on re-gional geological survey and detailed data collection on the important points and used the ways and means of the rock stratigraphy, sedimentology, sequence stratigraphy, tectonics and paleontology, summarized the previous data systematically and com-bined with the regional geological background characteristics,then by settle and con-trast of the field data, for LuFeng LuFeng population strata have been studied in de-taiL,founding that Lufeng region Lufeng Gr can be divided into four members:the characteristics of lithology combination is dark-purple, gray-green, yellow-green mudstone, siltstone and powder-the slender quartz sandstone in the lower part which is the Lufeng Gr for first member (JL-1); in the central-lower part of Lufeng Gr for second member (JL2), its lithotogy are fresh-purple, gray-purple, dark-purple fine-grained clastic; there are gray medium-coarse-fine-grained lithic feldspar quartz sandstone, bright-red, dark-purple, gray siltstone and mudstone in the cen-tral-upper that is sedimentary characteristics of rock of the Lufeng Gr for third mem-ber (JL3);in the upper the fuchsia conglomerate, gray-white, gray coarse-grained sandstone, siltstone, mudstone is the Lufeng Gr for forth member (JL4).The bottom of the Lufeng Gr for first member (JL-1) and the lower stratum showed contact within the study region and periphery of Chuxiong Basin,which conformable contacts with the system Premises of Trissic Shezi Fm in northern Maozhi region,but in the southern region,it showed an angular unconformity with the pre-Sinian Etouchang Fm. And the internal sedimentary exist the different interface of deposition, which is caused the different micro-environment in the basin. Hiatus and a variety of interface and event can interface stratigraphic correlation in the region. Contrasting profile lithology combination, biological composition, sedimentary structures of different location in basin, and using the theory of modern sequence stratigraphy, the Lufeng Gr can be divided into two second-order sequences, including four third-order sequences by a tow-stand system tract (LST), the chief component of transgressive system tract (TST) and a high-stand system tract (HST). Specific performance is that he Lufeng Gr for first member (JL1) and Lufeng Gr for second member (JL2) is Lacustrine (fine-grained clastic deposition) and upward shift the Lufeng Gr for third member (JL3) lower part,the water shallow that is Delta facies (clastic sediments), the the debris rock group of in the central-upper part of he Lufeng Gr for forth member (JL4) showed that the water more quickly darken,then up again lighter in the central-upper par of he Lufeng Gr for forth member (JL4) becomes lower and forms the Delta fa-cies.To top of the Lufeng Gr, the region overall rapid uplift and replaced by mature fluvial deposition. The overall water of Lufeng basin experienced Lacustrine (small)-Delta facies-Lacustrine-Delta facies-Meandering fluvial deposition alternative course. Comprehensive study found that Jurassic Lufeng region in Yunnan is a small and medium-sized depression basin that is long from north to south and narrow from west to east Other the west adjacents Chuxiong; the north nears Yuanmou; south is cross to Yuxi Yimen and Chuxiong Shuangbai; the east nears Kunming Wuding, Luquan and Anning, the overall area of approximately1200km2.The development of the basin affected by the Yanshan movement structure and experienced extrusion de-pression settlement-settlement-uplift ect three stages. |
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