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对Granite山花岗岩类岩石的详细研究和Owl Creek山以及拉拉米山脉一些花岗岩类样品的初步研究表明,中怀俄明地区自早前寒武纪以来一直是一个铀成矿区。这表明在中怀俄明铀成矿省内部及其附近有可能发现早前寒武到全新世年龄的几种不同类型的铀矿床。该区前寒武纪花岗岩的钍含量一般都比引用的典型花岗岩的钍含量明显高。地表样品的铀含量一般都不明显高,但同位素证据表明大多数样品在新生代期间丢失了很多铀。根据Granite山样品新测定的Th/U比值多大于5,而根据~(208)Pb和~(206)Pb的计算,如果铀没有丢失则Th/U比值小于3。因此,建议采用围岩钍含量作为铀成矿省的标记比铀含量更好,且Th/U比值可能是铀丢失的有用的标记。
A detailed study of Granite rocks in Granite and a preliminary study of some granite samples in Owl Creek and the Laramis show that the Middle Wyoming region has been a uranium mineralization since Early Precambrian. This suggests that several different types of uranium deposits from the early Cambrian to the Holocene may be found in and around Wyoming uranium mineralization province. The Cambrian granites in this area generally have a much higher thorium content than the typical thoriated granite. Uranium content of surface samples is generally not significant, but isotopic evidence indicates that most samples lost much of their uranium during the Cenozoic. The Th / U ratio newly determined based on the Granite sample is more than 5, whereas the Th / U ratio is less than 3 if uranium is not lost from ~ (208) Pb and ~ (206) Pb calculations. Therefore, it is recommended to use the thorium content of the surrounding rock as a marker for uranium metallogenic provinces that is better than uranium and that the Th / U ratio may be a useful marker of uranium loss.