Lithogenesis Research of Silicalite and Limestone of Silurian in the Uranium Metallogenic Belt in Western Qinling
西秦岭铀成矿带中志留系硅岩灰岩的成因研究

The genesis of Silurian silicalite and limestone was studied from the geological setting,lithology and geochemistry especially the REE geochemistry in this paper based on many measured sections and laboratory analyses. The sedimentary environment of micrite limestone and pellet micrite limestone was the upland under deeper water with low water energy. The pellets were composed of organism pellets and radiolarite.There are two types of silicalite:the organic deposit (type I) and the silicalite silicanzed from limestone (type II).They are obviously different in the geologic setting,texture and structure,geochemistry of rare element and REE etc. As sedimental environmental model was proposed for early Silurian in the Uranium metallogenic belt in Western Qinling based on the synthetical study.