Geological Characteristics And Genetic Analysis Of Tianjing Iron Deposit In Jinning County Of Yunnan Province

Tianjing iron deposit in Jinning county Yunnan province is located in the place that the south by west of Yunnan province "mountain" type structure of spine is adjacent to the front arc. It starts from the south side of Dongshan Mountain to New Longtan Mountain; it is just located in iron ore zone of the earth’s axis of Kangdian, so the metallogenic condition is super. But because of the research on the metallogenic background and metallogenic mechanism of Tianjing iron is mainly conducted in the sixty or seventy’s, so there was little analysis on it. So the specific causes of Tianjing iron deposit is not clear, urgent analysis needs to carry on it in order to use the theoretical support for deep ore prospecting and regional prospecting.Comprehensive analysis about regional metallogenic background is done in this paper, and detailed analysis about Tianjing iron deposit is done. Distribution characteristics of orebody, ore-hosting structur of mining area and source of ore forming material and near ore forming age is found out by the research on the deposit geological survey, morphological description of orebody, summary of ore characteristics, contrast of regional ore deposits and other aspects. Combined with the study of Dianzhong iron deposit, the metallogenic mechanism of Tianjing iron deposit is discussed, and the metallogenic model of eluvialore bed in Dianzhong.According to the date, Tianjing iron ore is formed with several large ore deposit and more than ten little ore deposit. Large ore deposit is surrounded by little ore deposit. Meitang and Dalongkou formation of mesoproterozoic Kunyang group mainly develop in ore area. A northeastern fault whose length is more than 5000 kilometers goes through this area and this area was invaded by several diabase dikes. Host rock is the limestone of Dalongkou formation, mineralization choice about surrounding rock is strong. Different ore bodies are controlled by NE fault and its secondary small fault. Orebody exists in the fault and the karst space of limestone and the direction of the orebody is SW-NE.Through the patio analysis of the regional geology and the mineral characteristic s of iron ore, the iron ore mining area has experienced many period of formation and multiple stages of mineralization, can be divided into:source bed rock, the principal c ycle (Jinning period) transformation and enrichment, the posterior cycle (Yanshanian and Iindo-chinese epoch) re-transformation, the late recent periods supergene enrichm ent of reform. Its minerals come from the ore rock formations with high iron content which is above the ore-hosted strata, is a illuviation hematite beds and then weatherin g to form Slope sand deposit.