论文部分内容阅读
THE Wengfu phosphorite deposit, a superlarge ore deposit, is located in the counties of Weng an andFuquan, Central Guizhou, China. The deposit has been considered as typical sedimentary one since itwas found, but our new approach suggests that its formation be related to contemporaneous submarine hydrothermal activity. The Wengfu phospohorite deposit, belonging to Doushantuo stage of Late Sinian (Latest Precambrian), was divided into two ore layers intercalated by dolomites and siliceous rocks. In the phosphoritesthere exist abundant fossils, including newly found “Weng an Biota” which contain the fossils of multicellular thallophytes as well as animal embryos and sponges. Besides the common sedimentary structures, the phosphorites and the coexisting siliceous rocks alsopossess obvious hydrothermal sedimentation features, which are presented as the following: (i) The coexisting cherts are, lenticular in distribution and with high SiO_2 purity and high homogeneous temperatures (up to 150℃) of the inclusions, characterized by hydrothermal sedimentation. (ii) The special “pellets” or “pisolites” formed by hydrothermal eruption are common in the phos-
THE Wengfu phosphorite deposit, a superlarge ore deposit, is located in the counties of Weng an and Fuquan, Central Guizhou, China. The deposit has been considered as typical sedimentary one since itwas found, but our new approach suggests that its formation be related to contemporaneous The Wengfu phospohorite deposit, belonging to Doushantuo stage of Late Sinian (Latest Precambrian), was divided into two ore layers intercalated by dolomites and siliceous rocks. In the phosphoritesthere exist abundant fossils, including newly found “Weng an Biota ”其他 的 相互 地图.“ The contain the fossils of multicellular thallophytes as well as animal embryos and sponges. The phosphorites and the coexisting siliceous rocks alsopossess obvious hydrothermal sedimentation features, which are presented as the following: (i) The coexisting cherts are, lenticular in distribution and with high SiO_2 purity and high homogeneous temperatures (up to 150 ° C) of the inclusions, characterized by hydrothermal sedimentation. (Ii) The special ”pellets“ or ”pisolites" formed by hydrothermal eruption are common in the phos-