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矿床地质  2005 

东川蓑衣坡硅质岩型铜矿床的地质地球化学特征及成因

Keywords: 地质学,硅质岩型铜矿床,地质地球化学特征,蓑衣坡

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Abstract:

蓑衣坡硅质岩型铜矿床产于元古宙裂谷带,矿化主岩为块状硅质岩和条纹(带)状硅质岩;块状硅质岩的SiO2含量为85.66%~96.74%,条纹(带)状硅质岩的SiO2含量为74.83%~87.52%;在TiO2-Al2O3和(K2O+Na2O)-Al2O3关系图上和(Co+Ni)_(As+Cu+Mo+Pb+V+Zn)关系图上,其成分投影点均落入与海底热水系统有关或热水沉积岩区的硅质岩区;蓑衣坡矿区矿石的稀土元素总量变化大,且显示轻稀土元素富集,叠加的成矿作用引起轻稀土元素含量升高;并具铈负异常、铕异常不明显的特点。矿石内矿物流体包裹体的均一温度为121~257℃,盐度w(NaCleq)为6.2%~8.3%,成矿流体属K+_Ca2+_SO2-4型和K+_Mg2+_SO2-4型。矿石的δ34S值为-14.8‰~+17.2‰,δ18O值为4.9‰,矿石中石英的δ18O值为12.4‰~16.3‰,位于热泉型石英的δ18O值变化区间(12.2‰~23.6‰)。矿石中黄铁矿内流体包裹体的δD值为-116.2‰,其δ18OH2O值为-5.7‰,接近美国黄石公园酸性热泉的δD值和δ18O值。含矿硅质岩的206Pb/204Pb比值为17.947~18.951,207Pb/204Pb比值为15.606~15.711,208Pb/204Pb比值为36.466~38.496。根据矿床地质地球化学特征,笔者认为,蓑衣坡硅质岩型铜矿床的成因类型属裂谷处于拉张裂陷阶段发生的喷流沉积作用形成的硅质岩型铜矿床。

References

[1]  WangJ B, Qin K Z, Wu Z L, et al. 1998. Volcanic-exhalative-sedimentary lead-zinc deposits in the southern margin of the Altai, Xinjang [M]. Beijing: Geol. Pub. House. 18~45 (in Chinese).
[2]  Zheng M H, et al. 1994. The Stratabound gold deposits of exhalation type and turbidity type[ M ]. Chengdu: Sichuan Publishing House of Science and Technology. 110~120 (in Chinese).
[3]  Ran C Y. 1990. Ore-genetic mechanism of stratiform and strata-bound copper deposits in Xikang-Yunnan axis[M]. Beijing: Geol. Pub.House (in Chinese).
[4]  Tu G Z. 1988. Geochemistry of stratiforn and strata - bound deposits in China[M]. Beijing: Science Press. 131~152. (in Chinese).
[5]  Ding T P. 1980. Hydrogen and oxygen isotope geochemistry[ M ]. Beijing: Geol. Pub. House (in Chinese).
[6]  Gong L, He Y, Chen T Y. 1996. Proterozoic rift copper deposits in Dongchuan, Yunnan Province[ M]. Beijing: Metallurgical Industry Press. 73~150 (in Chinese).
[7]  Han F, and Hutchinson R W. 1989. Evidence for exhalative origin for rocks and ores of the Dachang tin polymetallic field: the ore-bearing formation and hydrothermal exhalative sedimentary rocks [ J ]. Mineral Deposits, 8 (2) :25~40 (in Chinese with English abstract).
[8]  Lin W D and Li Z Q. 1995. The thermal water sediments and it\\' s siliceous rock-hosted copper deposit in Lanipen deposits[J ]. Southwestern Geology for Mineral Resources, ( 1-2 ): 50 ~ 65 ( in Chinese with English abstract).
[9]  Pollock S C. 1987. Chert Formation in an Ordovician volcanic arc[J].Journal of Sedimentary Petuology, 157 (1) :75~84.

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