Study On Sedimentary Environment Of Feixianguan Formation In Lower Triassic In Huize Area, Yunnan Province

Huize area is one of the important ore producing areas in Yunnan Province, with zinc, copper, iron, phosphorus. The Feixianguan Formation of lower Triassic is widely distributed in the Huize area Yunnan province, with the complex sedimentary environment and bearing the copper sandstone. So the research can understand more in-depth the changes in the depositional environment of the area during the Triassic period, the tectonic evolution and mineral metallogenic background. That the previous rough study on its sedimentary environment is the lake facies deposition, this study has divided in detail and further exploration of mineral resources, at the same time to improve the basic geological data, but also has important theoretical and practical significance to expand the potential of mineral resources.Through the field profile and indoor synthesis of the Feixianguan Formation lithology, according to the lithology and color characteristics, the formation is divided the upper and lower two segments, the lower segment of the lithology is purple red mud silty sandstone, mudstone and so on, containing a small amount of thin bedded micrite; Colors are purple, dark purple, dark gray; Sedimentary sequence for silty mudstone, sandstone and lithic siltstone; Sandstone grain size cumulative probability map displays saltation and suspension handling; Main sedimentary structures are inclined bedding wave,ripple bedding, cross bedding; There are conodonts in paleontology. Paleocurrent rose diagram displays two-way flow, a as against the land of the North West, another is by the sea in the south-east direction; Feixianguan Formation sandstone found special glauconite, to restore the environmental characteristics; Feixianguan Formation palaeogeography of early characteristic was transgressive background, development of coastal lagoon, delta front, to the late for the regression environment, development of delta front and prodelta, overall transgressive regressive cycles.According to the characteristics that ancient water, and study of special mineral mud gravel evolution analysis shows that the Feixianguan Formation overall area is a set of transitional facies, Delta. The middle Lu Bei, Lu Zhu and eastern slope Feixianguan Formation under develops coastal lagoon, the whole bottom of Feixianguan Formation develops delta front small branch channel deposition and vertical upward alternately in front of delta front facies and delta phase, which indicates that Feixianguan Formation has occurred in sedimentary cycles.The study area from the northwest to the southeast, the sedimentary environment are basalt highland debris flow-coastal lagoon sedimentary-wave transformation of delta front facies and prodelta.