The Rössing mine in Namibia is the earliest alaskite-type uranium mine,ranking the top 10 globe uranium mines. However,the backup resources are seriously insufficient,therefore it is urgent to carry out exploration to expand resources and ensure the sustainable development of the mine. Based on the secondary data development,the authors carried out field geological survey,large-scale geological mapping,and ground energy spectrum measurement on the main uranium deposits in the mining area,studied the typical uranium deposit and identified uranium mineralization characteristics and ore-controlling factors. It was considered that the alaskite-type uranium deposit was the products of regional tectonic-magmatic evolution,which was crystallized from granitic magma. The ore-forming material was derived from the anatexis of the ancient basement rocks. The diversity of source rocks and the heterogeneity of melting resulted in the capacity variations in the ore-bearing alaskite. The localization of the deposit is controlled by NNE-trending regional faults, dome (fold) turning ends and structural variation sites. Ore-bearing pluton intruded along the structural and weak stratigraphic planes,with post-mineralization hydrothermal alteration and supergene leaching and enrichment.On the basis of summarizing the geological background, metallogenic and ore-controlling pattern of uranium mineralization,this paper defined the prediction factors of uranium mineralization and extracted the prediction factors including uranium deposits buffer zones,alaskite distribution areas,regional tectonic buffer zones,marble exocontact zones,alteration development zones, aerial radiometric uranium anomaly zones and ground gamma spectrometry anomaly zones. Using the comprehensive information geological unit method,uranium metallogenic prediction was conducted and 14 new uranium prospective sectors were delineated in the Rössing mining licence area with approximately 140 000 tons potential resources. This achievement indicated significant uranium potential in the periphery of the Rössing deposit and worthy more exploration efforts. The 5 predicted level-A prospects are the focus for the next exploration. Among which,the A1(Z17-19)sector has been verified as a super-large uranium deposit through drilling,demonstrating remarkable prospecting achievements.
| 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 |