辽宁杨木杆硼矿床地质地球化学特征  

GEOLOGICAL AND GEOCHEMICAL CHARACTERISTICS OF THE YANGMUGAN BORON DEPOSIT, LIAONING PROVINCE

作　　者：谢宏远[1,2,3] 冯本智[1,2,3] 邹日 琚宜太[1,2,3] 

机构地区：[1]中国科学院地质研究所 [2]长春科技大学地质系 [3]中国科学院广州地球化学研究所

出　　处：《矿床地质》1998年第4期355-362,共8页Mineral Deposits

基　　金：地矿部91年度行业基金

摘　　要：杨木杆硼矿位于辽宁省宽甸县，产出于古元古代南辽河群下部里尔峪岩组中，为一中型硼镁石型硼矿。矿体走向ＳＥ，倾向ＮＥ，倾角７０°～８０°，直接赋矿岩石为蛇纹岩、蛇纹石化大理岩，矿体顶板出现有热水沉积的电英岩。硼矿石主要由纤维硼镁石、板状硼镁石及蛇纹石、白云石等组成。常见的变余沉积及变质、交代等组构。硼矿石品位Ｂ２Ｏ３随ＭｇＯ含量增长先是稳步增长，然后在Ｂ２Ｏ３含量大于７％时，ＭｇＯ含量稳定在４５％～４８％范围内。矿石中富含Ｃｓ、Ｎｄ、Ｔａ、Ｓｎ、Ｃｄ等微量元素及Ｆ、ＣＨ４等挥发分，稀土总量从５．７３×１０－６～７０．９８×１０－６，具Ｅｕ负异常。δ１３Ｃ在－２．６‰～－１０．４‰，δ１１Ｂ在９．６‰～１１．１‰。杨木杆硼矿为受变质的与深源火山活动有关的热水沉积矿床，同时存在的蒸发气候条件提高了硼富集成矿的效率。Located in Kuandian County, Liaoning Province, the Yangmugan boron deposit is a medium size szaibelyite type deposit occurring in Lieryu Formation within the lower part of the Paleoproterozoic South Liaohe Group. Orobodies strike SE, dip NE and have dip angles 70°-80°. Host rocks are yellowish green and black serpentinites and serpentinized marble, with thick bedded hydrothermally deposited laminar tourmalite also seen in the hanging wall of the orebodies.Ore minerals comprise mainly fibrous and tabular szaibelyite, whereas gangue minerals consist chiefly of serpentine, forsterite, phlogopite and dolomite. Blasto sedimentary, blastic and metasomatic textures make up the main ore textures. The ore grade of B 2O 3 is closely related to the content of MgO. The ores contain abundant trace elements like Cs, Nd, Ta, Sn and Cd as well as rich volatiles such as F and CH 4. The REE content ranges from 5 73×10 -6 to 70 98×10 -6 ,and the chondrite normalized REE patterns have positive or negative slopes and exhibit negative Eu anomalies. δ 13 C values are -2 6‰～ -10 4‰, and δ 11 B values are 9 6‰～11 1‰. The Yangmugan boron deposit is of the hydrothermal sedimentation type closely related to mantle derived volcanic activity, and the coexistent evaporate climatic condition raised the efficiency of ore concentration. After its formation, the primary boron deposit underwent regional metamorphism of amphibole facies and two phases of intense deformation during the Luliang orogeny.

关 键 词：硼矿床 地质地球化学 古元古代 硼矿石品位 

分 类 号：P619.211[天文地球—矿床学]