地球科学与环境学报
地毬科學與環境學報
지구과학여배경학보
JOURNAL OF EARTH SCIENCES AND ENVIRONMENT
2014年
1期
128-140
,共13页
冯延清%钱壮志%张江江%崔智昊%姜超%孟德明
馮延清%錢壯誌%張江江%崔智昊%薑超%孟德明
풍연청%전장지%장강강%최지호%강초%맹덕명
小岩体%成矿规律%钼矿床%花岗岩%斑岩%燕山期%东秦岭
小巖體%成礦規律%鉬礦床%花崗巖%斑巖%燕山期%東秦嶺
소암체%성광규률%목광상%화강암%반암%연산기%동진령
small intrusion%metallogenic regularity%Mo deposit%granite%porphyry%Yanshanian%East Qinling
总结了东秦岭钼矿带中与中酸性小岩体有关的斑岩矽卡岩型钼矿床地质特征;对其成矿时空分布、成矿特征以及成矿物质来源进行讨论,归纳其规律性;通过分析大岩基与中酸性小岩体的主量、微量元素数据及形成年龄,探讨二者的关系。结果表明:东秦岭与岩浆作用有关的钼矿床形成时间可分为141~156、110~138 Ma两个阶段;第一阶段形成的矿床主要集中在东秦岭南部,第二阶段主要集中在东秦岭北部;矿床成矿年龄由西至东、由南至北总体上具有逐渐变新的趋势;钼矿床具有成群成带、分段集中展布的特点,并且这些集中段之间的距离基本相等;成矿岩体的岩浆演化系列对矿化元素组合有一定的控制作用,具体表现为岩浆酸性越强,钼成矿越有利;微量元素及同位素资料显示成矿物质主要来源于地壳,地幔物质作用并不明显;大岩基与小岩体有成因联系,系同源岩浆演化的产物,大岩基为小岩体提供了充足热量与物质来源,从而出现小岩体成矿的现象。
總結瞭東秦嶺鉬礦帶中與中痠性小巖體有關的斑巖矽卡巖型鉬礦床地質特徵;對其成礦時空分佈、成礦特徵以及成礦物質來源進行討論,歸納其規律性;通過分析大巖基與中痠性小巖體的主量、微量元素數據及形成年齡,探討二者的關繫。結果錶明:東秦嶺與巖漿作用有關的鉬礦床形成時間可分為141~156、110~138 Ma兩箇階段;第一階段形成的礦床主要集中在東秦嶺南部,第二階段主要集中在東秦嶺北部;礦床成礦年齡由西至東、由南至北總體上具有逐漸變新的趨勢;鉬礦床具有成群成帶、分段集中展佈的特點,併且這些集中段之間的距離基本相等;成礦巖體的巖漿縯化繫列對礦化元素組閤有一定的控製作用,具體錶現為巖漿痠性越彊,鉬成礦越有利;微量元素及同位素資料顯示成礦物質主要來源于地殼,地幔物質作用併不明顯;大巖基與小巖體有成因聯繫,繫同源巖漿縯化的產物,大巖基為小巖體提供瞭充足熱量與物質來源,從而齣現小巖體成礦的現象。
총결료동진령목광대중여중산성소암체유관적반암석잡암형목광상지질특정;대기성광시공분포、성광특정이급성광물질래원진행토론,귀납기규률성;통과분석대암기여중산성소암체적주량、미량원소수거급형성년령,탐토이자적관계。결과표명:동진령여암장작용유관적목광상형성시간가분위141~156、110~138 Ma량개계단;제일계단형성적광상주요집중재동진령남부,제이계단주요집중재동진령북부;광상성광년령유서지동、유남지북총체상구유축점변신적추세;목광상구유성군성대、분단집중전포적특점,병차저사집중단지간적거리기본상등;성광암체적암장연화계렬대광화원소조합유일정적공제작용,구체표현위암장산성월강,목성광월유리;미량원소급동위소자료현시성광물질주요래원우지각,지만물질작용병불명현;대암기여소암체유성인련계,계동원암장연화적산물,대암기위소암체제공료충족열량여물질래원,종이출현소암체성광적현상。
Geological characteristics of porphyry-skarn Mo deposits, which were related to intermediate-acid small intrusions in Mo ore belt of East Qinling,were summarized;spatio-temporal distribution, metallogenic characteristics and ore-forming material sources were discussed,and then the metallogenic regularity was discovered;compositions of major element and trace element and ore-forming age for large batholith and intermediate-acid small intrusions were analyzed,and the relationships of them were discussed.The results show that the ore-forming ages of East Qinling Mo deposits related to magmatism can be divided into two stages, 141-156 Ma and 110-138 Ma;the deposits forming in the former stage are mainly distributed in the south of East Qinling,and those in the latter stage are mainly distributed in the north;the ore-forming ages become younger gradually from west to east and from south to north;Mo deposits distribute in groups or belts,and concentrate on sections with equal distance;the combination of mineralization elements is controlled by the magmatic evolution series,and the more acid magma is,the better Mo mineralization is;data of trace element and isotope indicate that the metallogenic materials are mainly from the crust,and the effect of mantle are not obvious;a close genetic relationship is present between large batholith and small intrusions from the comagmatic evolution,and large batholith provides heat and material substance for small intrusions,so that there are large orebodies hosted in small intrusions.