营口后仙峪硼矿容矿火山－热水沉积岩系特征  

THE FEATURES OF ORE-HOSTING VOLCANIC-HYDROTHERMAL SEDIMENTARY SERIES IN HOUXIANYU BORON DEPOSITS,YINGKOU, LIAONING

作　　者：邹日[1] 冯本智[1] 

机构地区：[1]中国科学院广州地球化学研究所,长春地质学院

出　　处：《地球化学》1995年第C00期46-54,i002,共10页Geochimica

基　　金：博士点基金;国家自然科学基金(青年基金)

摘　　要：营口后仙峪硼矿的容矿岩系由海相酸性火山凝灰岩夹热水沉积岩组成。二者在垂向上呈韵律状互层，横向上相变过渡，类似复理石构造。凝灰岩呈镶嵌粒状变晶结构、筛状变晶结构、条纹条带状构造，主要由钾长石和电气石组成（钾长石５０％－９０％，电气石５％－３０％），在化学成分上以富Ｂ和Ｋ为特征（Ｂ＿２Ｏ＿３２。０％－２．２％，Ｋ＿２Ｏ７．２％－９．４％）其微量元素组成及硼同位素组成（＋３．９‰－＋４．５‰）均与火山岩一致。热水沉积岩主要形成于火山活动的间歇期，包括富硼硅质岩、富硅的镁质碳酸盐岩和含水镁硼酸盐矿体。它们具有条纹条带状构造和变余结核－球状构造，化学成分以富Ｂ、Ｍｇ和Ｓｉ为特征，微量元素组成和含量与火山岩相似，而稀土配分模式与海相化学沉积岩相似，特别是硼矿石的硼同位素组成（＋９．６‰－＋１１．１‰）与电英岩中电气石的值（＋９．２‰－＋９．７‰）十分相似，证明硼矿床为热水沉积成因。The Boron-bearing formation (Lieryu Formation) in Yingkou, Liaoning belongs to the lower part of Liaohe group. They underwent the early Proterozoic (about 2000 Ma) amphibolite facies regional metamorphism and intensively deformations for times. The boron-bearing formation (rich in boron, 160× 10-7290× 10-6) in Houxianyu boron deposits mainly consists of submarine alkali-rich acidic volcanic rocks interstratificated by boron-rich hydrothermal sediments, interlayered with several basic volcanics. The ore-hosting volcanic-hydrothermal sedimentary series consisting of tuffs and exhalites was formed in the intermittent period between two intensive volcanism. The hydrothermal sedimentary series includes boron-rich silicalite.silica-bearing magnesian carbonate, and original hydro-magnesian borates ore bodies.With obviously sedimentary fabrics and similar trace element chemistry to the volcanics, they might represent the results of volcanic exhalation-hydrothermal sedimentation in the secondaty faulted volcanic basins, controlled by the deep-seated syntec tonic faults striking towards to W-E. The δ11B values of ores (+9.6‰-11.1‰) are similar to those of exhallogenic tourmalites. (+9.2‰-+9.7‰). This demonstrates that the formation of the boron deposits are genetically related to the hydrothermal sedimentation.

关 键 词：营口市 后仙峪硼矿 火山-热水沉积岩 岩系特征 微量元素 

分 类 号：P619.21[天文地球—矿床学] P588.2[天文地球—地质学]