地质科技通报 (Sep 2024)
Geological characteristics, controlling factors and prospecting directions of associated cobalt deposits in the Weiningbeishan area, Ningxia
Abstract
Weiningbeishan is located in the eastern section of the North Qilian orogenic belt, which is one of the regions with the most favorable conditions for cobalt mineralization in Ningxia. Objective To understand the formation conditions and mineralization regularity of cobalt deposits in this area, Methods this paper summarizes the geological characteristics, controlling factors, and spatiotemporal distribution patterns of typical associated cobalt deposits in Weiningbeishan based on detailed field investigations and previous exploration results and proposes future exploration directions. Results Research has shown that the Datonggou copper cobalt deposit, Chaliangzi iron cobalt deposit, and Tuyao iron cobalt deposit are currently three representative associated cobalt deposits discovered in Weiningbeishan area. Among them, three copper cobalt ore bodies were discovered in Datonggou, with the highest Co grade of 0.06%. Cobalt-bearing minerals mainly include pyroxenite, cobalt-bearing pyrite and cobalt-bearing limonite. There are 4 ore belts and 8 iron cobalt ore bodies are distributed in Chaliangzi, with the highest Co grade of 0.03%. The cobalt-bearing minerals are mainly cobalt-bearing limonite. Only one iron cobalt ore body was found in Tuyao, with the highest Co grade of 0.20%. The cobalt-bearing minerals are similar to those of Chaliangzi. Cobalt mineralization is evidently controlled by faults, with the western cobalt deposit mainly controlled by east-west faults and their combined control with northeast faults, while the eastern cobalt deposits are mainly controlled by north-south faults. Cobalt ore are mainly found in the Upper Carboniferous Tupo Formation, which was the main source strata. Lithological control is mainly observed at the "silica-calcium interface" and the lithological combination interface with different competence, which controlled the mineral precipitation. The cobalt metallogenic era was the Indosinian. Cobalt was closely related to Cu, Au, Fe and Mn. Cobalt related to Cu and Au were mainly distributed in the west, while cobalt related to Fe and Mn were mainly distributed in the east. The diversity of mineral species in this region may be attributed to the multistage superimposition of structures and hydrothermal activity. Conclusion The most favourable locations for identifying cobalt deposits are the east-west faults and their intersections with the northeast faults in the western part, the north-south Carboniferous and Devonian interface faults in the eastern part, the " silica-calcium interface " within the Tupo Formation, and the lithological combination interfaces with different competence. Malachite alteration and ferritization are the most important prospecting indicators for copper cobalt deposits and iron cobalt deposits.
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