Dalishu uranium deposit is a carbonate rock type uranium deposit located at the Lukan fault hanging wall in the southeast limb of Xiongwu anticline. Researches on this uranium deposits are still seldom reported. Based on the field geological survey and collection of uranium ore samples in trenches and boreholes, this paper conducted a study on mineralogy,geochemistry,and genesis of the deposit. The study show that the ore body is controlled by the northeast-trending faults and the secondary Si-Ca structural planes and closely related to organic matters. The main uranium minerals in the ore are pitchblende and uraninite,and the uraninite minerals,which are closely associated with pyrite and “black”organic matters. The trace elements such as V,Cr,Co,Ni,Cu,Zn,and Mo are enriched in the ore and the wall rocks.The rare earth element distribution pattern is“right-inclined” with the enrichment of LREE and negative δEu anomaly,indicating a certain genetic relationship with the Cambrian black rock series. It believed that the ore-forming materials maybe come from the Cambrian Niutitang and Laoba formation,the deposit was formed by deep hydrothermal action which extracted the uranium from the Cambrian basement ore-forming materials and carried to favorable areas under the orogenic background of Himalayan period.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |