Abstract:
This paper is the result of mineral exploration engineering.
Objective Straz area (Bohemia Basin, Czech Republic) is a well–known uranium metallogenic area. The mineralization of sandstone–type uranium deposits is complex. Determining its metallogenic characteristics and metallogenic model is of great significance to perfect the metallogenic theory of sandstone–type uranium deposits and know the prospecting and exploration of the similar uranium deposits in China.
Methods On the basis of summarizing the geological characteristics and metallogenic conditions of sandstone–type uranium deposits in the Straz area, this study focus on the uranium source, metallogenic stage and genesis of the deposits, and comparative studies are conducted by the similar sandstone–type uranium deposits in Songliao Basin.
Results The Straz deposit can be divided into six metallogenic stages according to its mineral assemblage characteristics, i.e., carbon-hydromica, hematite–kaolinite, uranium, polymetallic, limonite and hematite–quartz stage. Proterozoic and Paleozoic igneous, metasedimentary, and sedimentary rocks outcropping to the northeast of the Bohemia Basin are considered potential sources for uranium. The Lusatian Massif contains biotite granodiorite and porphyritic biotite granite with. The low Th/U ratios suggest that part of the uranium is probably present in leachable form and these rocks constitute viable uranium sources.
Conclusions The metallogenic model of the Straz area belongs to the “three factors and three majors”: Multi uranium source−basin basement primary uranium source, multi stage tectonic ore controlling–early Alps (about 70 Ma) orogenic movement, multi genetic composite mineralization– early Alps magmatic hydrothermal superimposed mineralization.
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