• 责任者：Zhao Zhenming (Xi’an Institute of Geology and Mineral Resources ; Xi’an 710054 ; China) ; Chen Shoujian
• 刊名：Geotectonica et Metallogenia
• 出版年：2013
• 卷期：37(3)
• 关键词：磁铁矿 ; magnetite ; 青海 ; Qinghai Province
• 页码：p.422-439
• 图表：8 illus., 8 tables, 59 refs.
• 分类号：1001
• issnNo：ISSN1001-1552
• isbnNo：CN44-1595/P

     The magnetite-rich Kaixinling iron ore-deposit locates in the Kaixinling area of south Tuotuo River on Tibetan Plateau. The Kaixinling area is located in the north Qiangtang tectonic province, which was a shallow coastal sea during Permian. The magnetite-rich iron ore-deposit is underlying the coal seams and overlying the limestone. In the profile 1 of the study area, the sandwiched ore deposit consists of two magnetite enriched layers, 14.4 and 16.0 m thick, with total iron content （TFe） of 66.30% and 64.00%, respectively. The main magnetite ore bodies are characterized by alternating dark and light color layers, the dark layer consists of magnetite and the light layer consists of quartz, hornblende and calcite. A 5 m thick hematite layer with TFe 22.20% and a 22 m thick altered allgovite layer are above two magnetite enriched layers. The profile 2 of the study area locates about 1.20 km SE of the profile 1. A single layer of compacted magnetite enriched layer is 1.52 m thick with TFe 63.87%, and characterized with calcite and dolomite veinlets less than 0.5 mm in width. The minor minerals in the ore deposit are hematite, goethite, quartz, hornblende, calcite, dolomite, fluorapatite, augite, galenite, graphite, and chlorite. Magnetites in the ores have girdle structure of crystalloid.  Based on the paleogeographic environment, characteristics of ore-bodies and wall rocks as well as results of chemical analyses, microscope spectroscopic, X-ray diffraction, electron probe and Laser-Raman spectrum, we speculate that the magnetite-rich ore-deposit was formed through oceanic volcanic diagenism and experienced later hydrothermal alteration. In particular, it is possibly that the iron in magma or hydrothermal fluid was enriched by diagenism in seabed under the physicochemical environment with seawater involvement. More iron ore deposits are expected to be found in this region in the future.