新疆准噶尔石钱滩组的生物群沉积环境及生物区系特征

ON FAUNAS,SEDIMENTAL ENVIRONMENT ND PALAEOBIOGEOGRAPHY OF SHIQIANTAN FORMATION,JUNGGAR,XINJIANG

Shiqiantan Formation is mainly composed of marine clastic rocks interbedded with limestone containing numerous fossils. It spreads in NW-SE direction along the piedmont of the Kalameli Mt. in eastern Junggar, Xinjiang. The strata are formed in the coastal area and shallow open sea which kept deepening during this period. It was structural region of the plate margin, and was situated in the warm temperate zone. The fossils are diversified and abundant, they are forminifers (including fusulinids), corals, brachiopods, bivalves, gastropods, porifers, bryozoans, ostracods, crinoids, trilobites and conodonts. Synthetic information about the age of the formation can be provided by studying the fossils, that is, the middle and lower parts of which are Middle Carboniferous, and the upper part may belong to Upper Carboniferous. The features of palaeobiogeography of Shiqiantan Formation are close to Ural and Novaya Zemlya and should be included in Boreal Realm. They are apparently different from the South and North China and East Europe, all belonging to the Tethys Realm.