气候变化领域集成服务门户(CCPortal): Genesis of the Large-Scale Kamado Magnesite Deposit on the Tibetan Plateau

CCPortal

DOI	10.3390/min14010045
	Genesis of the Large-Scale Kamado Magnesite Deposit on the Tibetan Plateau
	Yu, Xuhui; Hu, Guyue; Chen, Yuchuan; Xu, Ying; Chen, Han; Wang, Denghong; Huang, Fan; You, Shuisheng; Liu, Haiyong; He, Liang; Li, Yubin
发表日期	2024
EISSN	2075-163X
卷号	14 期号:1
英文摘要	Lacustrine strata-bound magnesite deposits associated with Alpine-type ultramafic rocks are hydrothermal in origin. The magnesite ores of the Kamado deposit are unconformably underlain by mid-Jurassic marine carbonate and ultramafic rocks of the Bangong-Nujiang ophiolite suite and are in fault contact with hanging wall rocks composed of siliceous sinter. Three types of cryptocrystalline magnesite ores can be identified in Kamado: (1) strata-bound massive magnesites, representing the main ore type in the upper part; (2) banded ores in the lower part; and (3) some vein and stockwork ore in the ultramafic wall rocks. Integrated scanning electron microscopy, C-O isotope analysis, and geochemical analyses were carried out on the Kamado deposit. The results indicate that: (1) the orebody is composed of magnesite, with accessory minerals of aragonite, opal, and chromite; (2) the siliceous sinter and relatively high B (32.0-68.1 ppm) and Li (14.7-23.4 ppm) contents of the magnesite ores reflect long-term spring activity in Kamado; (3) the light carbon (delta 13CV-PDB: -4.7 +/- 0.3 parts per thousand to -4.1 +/- 0.6 parts per thousand) and oxygen isotopic compositions (delta 18OV-SMOW: +12.3 +/- 0.3 to +16.3 +/- 0.1 parts per thousand) of the stockwork ores in the foot wall rocks indicated that the carbon in fractures in the ultramafic rocks is from a mixture of marine carbonate and oxidized organic-rich sedimentary rocks, reflecting a typical Kraubath-type magnesite deposit; and (4) the relatively heavy carbon isotopic (delta 13CV-PDB: +8.7 +/- 0.4 parts per thousand to +8.8 +/- 0.3 parts per thousand) composition of the banded magnesite ores in the lower segment may have formed from heavy CO2 generated by anaerobic fermentation in the lakebed. Additionally, the carbon isotopic (delta 13CV-PDB: +7.3 +/- 0.3 parts per thousand to +7.7 +/- 0.7 parts per thousand) composition of the massive magnesite ores in the upper segment indicates a decline in the participation of anaerobic fermentation. As this economically valuable deposit is of the strata-bound massive ore type, Kamado can be classified as a lacustrine hydrothermal-sedimentary magnesite deposit, formed by continuous spring activities under salt lakes on the Tibetan Plateau, with the Mg mainly being contributed by nearby ultramafic rocks and the carbon mainly being sourced from atmosphere-lake water exchange, with minor amounts from marine carbonate strata.
关键词	lacustrine hydrothermal-sedimentary mineralization ultramafic rocks suture zone geochemistry carbon isotopes oxygen isotopes
英文关键词	RARE-EARTH-ELEMENT; ISOTOPE GEOCHEMISTRY; HYDROMAGNESITE STROMATOLITES; GEOTHERMAL WATERS; ULTRAMAFIC ROCKS; ATMOSPHERIC CO2; LOW-TEMPERATURE; STABLE-ISOTOPE; WYOMING CRATON; VEIN-STOCKWORK
WOS研究方向	Geochemistry & Geophysics ; Mineralogy ; Mining & Mineral Processing
WOS记录号	WOS:001151173900001
来源期刊	MINERALS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/283837
作者单位	Chengdu University of Technology; China Geological Survey; Chinese Academy of Geological Sciences; China Geological Survey; Chinese Academy of Geological Sciences; China Earthquake Administration; Sichuan Earthquake Agency, CEA; Tibet University
推荐引用方式 GB/T 7714	Yu, Xuhui,Hu, Guyue,Chen, Yuchuan,et al. Genesis of the Large-Scale Kamado Magnesite Deposit on the Tibetan Plateau[J],2024,14(1).
APA	Yu, Xuhui.,Hu, Guyue.,Chen, Yuchuan.,Xu, Ying.,Chen, Han.,...&Li, Yubin.(2024).Genesis of the Large-Scale Kamado Magnesite Deposit on the Tibetan Plateau.MINERALS,14(1).
MLA	Yu, Xuhui,et al."Genesis of the Large-Scale Kamado Magnesite Deposit on the Tibetan Plateau".MINERALS 14.1(2024).