Geological-geochemical Characteristics and Genesis of Dongtangzi Pb-Zn Deposit in Fengxian-Taibai Ore Concentration Area of Shaanxi, China(PDF)
《地球科学与环境学报》[ISSN:1672-6561/CN:61-1423/P]
- Issue:
- 2018年第05期
- Page:
- 520-534
- Research Field:
- 基础地质与矿产地质
- Publishing date:
Info
- Title:
- Geological-geochemical Characteristics and Genesis of Dongtangzi Pb-Zn Deposit in Fengxian-Taibai Ore Concentration Area of Shaanxi, China
- Author(s):
- ZHANG Ge-li; WANG Rui-ting; TIAN Tao; DING Kun; GAO Wei-hong; GUO Yong-yong
- 1. Baoji No.717 Corps Limited of Northwest Nonferrous Geological and Mining Group, Baoji 721015, Shaanxi, China; 2. Northwest Nonferrous Geological and Mining Group Co., Ltd., Xi’an 710054, Shaanxi, China; 3. School of Earth Science and Resources, Chang’an University, Xi’an 710054, Shaanxi, China
- Keywords:
- geochemistry; Pb-Zn deposit; geological characteristic; ore genesis; ore-forming fluid; trace element; Fengxian-Taibai ore concentration area; Shaanxi
- PACS:
- P611.1+1
- DOI:
- -
- Abstract:
- Dongtangzi Pb-Zn deposit is located in the southern Fengxian-Taibai ore concentration area of South Qinling. The Pb-Zn ore body develops in the contact zone between the limestone of the Middle Devonian Gudaoling Formation and the phyllite of the Upper Devonian Xinghongpu Formation, and is controlled by the anticline structure and the calceo-lithium interface. The processes of hydrothermal mineralization can be divided into four stages, including vein-like sulphide-iron carbonate-quartz(Ⅰ), agglomerate sulphide-carbonate(Ⅱ), calcite quartz vein-depleted sulphide(Ⅲ) and large quartz carbonate vein-depleted sulphide (Ⅳ), and the Ⅰ and Ⅱ are major mineralization stages. The divergence of the understanding of Pb-Zn deposits in Dongtangzi, even in the entire Fengxian-Taibai ore concentration area, mainly focuses on the disputes of depositional genesis and hydrothermal genesis, and the study on the genesis of deposits is the basis for the deep ore-prospecting prediction in Fengxian-Taibai ore concentration area. The genesis of Dongtangzi Pb-Zn deposit was discussed through the studies of ore texture and structure, pyrite components, HO isotope composition, geochemical characteristics of trace elements in wall rocks and ores. The results show that the average values of w(Co)/w(Ni) in the vein-like and agglomerate pyrites are 18.70 and 8.56, respectively, indicating a hydrothermal genesis; the δDV-SMOW values of ores range from -94.9‰ to -83.3‰ with an average value of -87.0‰, and the δ18OH2O values range from 8.0‰ to 11.1 ‰ with an average value of 9.8‰, indicating that the ore-forming fluids mainly come from the magma water in the early stage, and the formation water and the atmospheric precipitation mix lately. Combination of the deposit geology, geochemistry, H-O isotopes and other characteristics, Dongtangzi Pb-Zn deposit might be one of magma hydrothermal type ores, which is affected by “calceo-lithium interface” between the limestone of the Middle Devonian Gudaoling Formation and the phyllite of the Upper Devonian Xinghongpu Formation. Therefore, the concealed rock bodies and mineralization centers may exist in the deep, and have a greater prospecting potential.
Last Update: 2018-10-01