Characteristic Of Ore-bearing Stratum On Chagnagnuoer Iron Deposit In Western Tianshan, Xinjiang

Xinjiang Western Tianshan Chagangnuoer iron deposit is one of the hundred million ton iron deposit in Awulale Metallogentic Belt(AMB). This paper relies the project " The research of Western Tianshan Awulale Iron ore Belt with iron ore metallogenic mechanism and control ", which research Chagangnoel iron ore stratigraphy characteristics of identified ore-bearing stratum age, geological background, and metallogenic prediction has important theoretical and practical significance. On the basis of an extensive collection of information on the previous done a lot of field geological survey work route, found the stratigraphic section and indoor comprehensive research work, focusing on the basis of ore-bearing rock formations and combinations of features, it features fossils, isotope age data, the Chagangnuoer iron ore mine stratigraphic features, including its lithological, fossils combination, volcanic eruptions build rhythm, isotopic age were studied, and the data were combined with the regional stratigraphic stratigraphic correlation. We made the following understanding:1.By Chagangnuoer mine geological section measurement system and a detailed geological survey and identified ore Carboniferous strata in the study area is great Dahalajunshan Formation, as a set of mainly acidic volcanic rocks of the coast- shallow marine volcanic formation, according to lithological composition which can be divided into upper and lower lithologic. Can be compared with the first and second lithologic section of Dahalajunshan Formation in the regional formation. Iron ore mainly occurs in second lithologic section of Dahalajunshan formation.2.By studying the distribution of volcanic rocks, scale, rhythm, eruptible gyration characteristics in ore-bearing stratum Dahalajunshan Formation. It is found that the first lithologic segment and second lithologic segment constitute two volcanic eruption cycles. The under section is the first eruption cycle, composed of 3-4 volcanic eruption rhythm, and the single eruption rhythm changes between 100-400 meters. The eruption of combinatorial sequences: volcanic brecia-tuff; or volcanic laca- tuff; or volcanic brecia- volcanic lava- tuff. The upper section is second cycles, and the rhythm of 4-6 eruption is composed of 100-500 meters.. The sequence of the eruption is: volcanic brecia tuff-tuff; volcanic agglomeratebrecia tuff-tuff; lava-tuff. Indicated the deformation environment of volcanic rock is littoral neritic facies eruption environment of late Paleazoic rift.3.According to the coral, brachiopoda and metacinas fossils which gathered this time in limestone interlayer of Dahalajunshan Formation ore-bearing stratum of Chagangnuoer Iron deposit. Include, Caninophyllum sp., Dibunophyllum sp., Gigantoproductus sp., Linoproductus sp., Cyclocyclicns sp.etc. And zircon U-Pb data age from rhyolitic is 321.2±2.3Ma, determined the geological age of Dahalajunshan Formation in Chagangnuoer ore-bearing stratum is Tournaisian-Visean of early Carboniferous.