This paper is devoted to the description of the early Triassic Dongchuanformation in Weining, western Guizhou, including its depositional sequences, lateral extent, and fossilassemblages as well. Lithostratigraphicall...This paper is devoted to the description of the early Triassic Dongchuanformation in Weining, western Guizhou, including its depositional sequences, lateral extent, and fossilassemblages as well. Lithostratigraphically, the formation contains four members , each of which corre-spends to a major depositional cycle composed upward of : reddish argillites, grey and purple siltstonesand sandstones, and limestones. The lithology, sedimental textures, and fossil assemblages indicate alacustrine environment which is in contrast with coeval sedimentary environments elsewhere inGuizhou. It is supposed to be a new stratigraphic unit.展开更多
The Zhushanchong barite deposits in Wanshan area, eastern Guizhou, occur asirregular veins or wedges in NE-, NNW-, and SN-striking and steeply-dipping faulted and fracturedzones in the slates of the Qingshuijiang form...The Zhushanchong barite deposits in Wanshan area, eastern Guizhou, occur asirregular veins or wedges in NE-, NNW-, and SN-striking and steeply-dipping faulted and fracturedzones in the slates of the Qingshuijiang formation of the Precambian Banxi group. The orebodies arecommonly n × 100 m long and 0. 4 to 1. 2 m wide and contain 95 percent of BaSO4. The spatialrelationship of orebodies suggest that the (-type faulted and fractured zones derived from regionallyNEtrending faults are most likely to serve as conduits in the initial stage of mineralization andsubsequently developed into hosting structures. The barite mineralizations are clearly influenced by multipleactivities of regional structures.展开更多
文摘This paper is devoted to the description of the early Triassic Dongchuanformation in Weining, western Guizhou, including its depositional sequences, lateral extent, and fossilassemblages as well. Lithostratigraphically, the formation contains four members , each of which corre-spends to a major depositional cycle composed upward of : reddish argillites, grey and purple siltstonesand sandstones, and limestones. The lithology, sedimental textures, and fossil assemblages indicate alacustrine environment which is in contrast with coeval sedimentary environments elsewhere inGuizhou. It is supposed to be a new stratigraphic unit.
文摘The Zhushanchong barite deposits in Wanshan area, eastern Guizhou, occur asirregular veins or wedges in NE-, NNW-, and SN-striking and steeply-dipping faulted and fracturedzones in the slates of the Qingshuijiang formation of the Precambian Banxi group. The orebodies arecommonly n × 100 m long and 0. 4 to 1. 2 m wide and contain 95 percent of BaSO4. The spatialrelationship of orebodies suggest that the (-type faulted and fractured zones derived from regionallyNEtrending faults are most likely to serve as conduits in the initial stage of mineralization andsubsequently developed into hosting structures. The barite mineralizations are clearly influenced by multipleactivities of regional structures.