沉积建造在辽东半岛古元古代杨木杆硼矿富集成矿过程中的重要作用  

Key Role of Sedimentary Formation Played in the Mineralization Process of the Paleoproterozoic Yangmugan Boron Deposit in Liaodong Peninsula, NE China

作　　者：赵岩[1] 张朋[1] 毕中伟[1] 寇林林[1] 杨宏智[1] 陈江[1] ZHAO Yan;ZHANG Peng;BI Zhong-wei;KOU Lin-lin;YANG Hong-zhi;CHEN Jiang(Shenyang Center of China Geological Survey,Shenyang 110034,Liaoning,China)

机构地区：[1]中国地质调查局沈阳地质调查中心,辽宁沈阳110034

出　　处：《地球科学与环境学报》2022年第2期207-219,共13页Journal of Earth Sciences and Environment

基　　金：国家重点研发计划项目(2018YFC0603804-3)。

摘　　要：为深入了解辽东半岛古元古代硼矿富集成矿过程中沉积建造的作用,选取辽东宽甸地区杨木杆硼矿开展系列野外考察、室内显微观察与同位素特征研究。该矿床硼矿体产出在辽河岩群里尔峪组和高家峪组内,是胶辽吉造山带内典型的硼镁石型矿床。对不同种类、不同品位矿石进行详细研究,发现变余结构与交代结构是主要的矿石结构特征,反映了明显的后期成矿热液交代过程。不同类型矿石和矿区围岩硫同位素测试显示,硼矿床的矿石δ^(34)S值为14.2‰~19.5‰,平均值为17.7‰,黑云变粒岩和电气变粒岩δ^(34)S值为12.0‰~13.3‰,平均值为12.7‰,蛇纹石化大理岩和蛇纹岩δ^(34)S值为15.6‰~23.1‰,平均值为19.3‰。硫同位素研究结果表明S有来自于辽河群沉积建造和火山建造的特征,结合前人硼同位素研究结果,认为沉积建造在硼矿就位过程中起到了重要作用。虽然硼矿的产出与胶辽吉古元古代造山带的演化密切相关,但活泼的B元素在多种地质过程中均可能活化和重新分布,难以单纯从硼矿的产出来限定胶辽吉造山带早期演化模型。The Yangmugan boron deposit is taken as the target on field observations, photomicrographs and isotopic characteristics to study the role of sedimentary formation played in the mineralization process of Paleoproterozoic boron deposit in Liaodong Peninsula. The Yangmugan boron deposit, which is a typical ascharite-type boron deposit within Jiao-Liao-Ji belt, has main ore bodies distributed in Li’eryu Formation and Gaojiayu Formation of Paleoproterozoic Liaohe Group. Detailed field and photomicrographs observations on different types and grades of ores review that palimpsest and metasomatic textures are main, reflecting a late metallogenic hydrothermal metasomatic process. Sulfur isotope reveals that the δ^(34)S values of ascharite range by 14.2‰ to 19.5‰ with an average of 17.7‰;biotite granulite and tourmaline granulite have δ^(34)S values from 12.0‰ to 13.3‰ with an average of 12.7‰;and serpentinized marble and serpentinite samples have δ^(34)S value from 15.6‰ to 23.1‰ with an average of 19.3‰. Sulfur isotope reveals that boron is sourced from the sedimentary and volcanic formations of Liaohe Group. Taking previous studies on boron isotope into consideration, it is believed that the sedimentary formation also plays a key role in the deposition of Yangmugan boron deposit. Although boron deposit has a close relationship with the evolution of Paleoproterozoic Jiao-Liao-Ji belt, the active B may have been activated and redistributed in many geological processes, the early evolution of Jiao-Liao-Ji belt can not be constraint only by the distribution of boron deposit.

关 键 词：硼矿 沉积建造 古元古代 里尔峪组 硫同位素 硼同位素 演化模型 胶辽吉造山带 

分 类 号：P611[天文地球—矿床学] P619.2[天文地球—地质学]