高校地质学报
高校地質學報
고교지질학보
GEOLOGICAL JOURNAL OF CHINA UNIVERSITIES
2013年
1期
1-11
,共11页
华仁民%张文兰%陈培荣%翟伟%李光来
華仁民%張文蘭%陳培榮%翟偉%李光來
화인민%장문란%진배영%적위%리광래
加里东期%花岗岩%大规模成矿%华南
加裏東期%花崗巖%大規模成礦%華南
가리동기%화강암%대규모성광%화남
Caledonian%granite%large-scale mineralization%South China
华南加里东期的花岗岩类在强度和广度上仅次于燕山期花岗岩,是华南大花岗岩省的重要组成部分.但是前人对于加里东期花岗岩类与成矿关系的报道较少,早期的研究甚至认为加里东期花岗岩一般不成矿.本文根据对近年来在某些地区和矿床出现的加里东期花岗岩类及相关矿化现象的初步研究成果,并结合对相关文献的调研,提出华南地区加里东期花岗岩类与该地区钨锡等金属大规模成矿作用之间具有相当密切的关系.这种关系主要表现在三个方面:(1)某些加里东期花岗岩、尤其是那些演化比较充分的加里东晚期花岗岩可能在晚阶段直接形成矿床,如湘东南的彭公庙、桂北的牛塘界、桂东北的桂岭、右江地区的钦甲等花岗岩体,但是其重要性相对较小;(2)某些加里东期花岗岩可能为该地区较晚期的成矿作用提供部分成矿物质来源,如在赣南的石雷、粤北的梅子窝等钨矿床可能有这种情况,在湘南的益将,加里东期的石英闪长岩为风化壳型稀土-钪矿化直接提供了成矿物质来源.(3)更为重要的是华南地区正是从加里东期开始进入了陆内演化的阶段,加里东期花岗岩类开启了以地壳物质重熔为主的华南大花岗岩省形成和发展的重要一幕,标志着华南陆壳进入不断成熟、亲石成矿元素不断向陆壳富集的阶段,多旋回花岗岩浆活动及其演化使钨锡等金属元素在燕山期花岗岩中高度富集,并最终导致了华南地区举世瞩目的燕山期大规模成矿作用.
華南加裏東期的花崗巖類在彊度和廣度上僅次于燕山期花崗巖,是華南大花崗巖省的重要組成部分.但是前人對于加裏東期花崗巖類與成礦關繫的報道較少,早期的研究甚至認為加裏東期花崗巖一般不成礦.本文根據對近年來在某些地區和礦床齣現的加裏東期花崗巖類及相關礦化現象的初步研究成果,併結閤對相關文獻的調研,提齣華南地區加裏東期花崗巖類與該地區鎢錫等金屬大規模成礦作用之間具有相噹密切的關繫.這種關繫主要錶現在三箇方麵:(1)某些加裏東期花崗巖、尤其是那些縯化比較充分的加裏東晚期花崗巖可能在晚階段直接形成礦床,如湘東南的彭公廟、桂北的牛塘界、桂東北的桂嶺、右江地區的欽甲等花崗巖體,但是其重要性相對較小;(2)某些加裏東期花崗巖可能為該地區較晚期的成礦作用提供部分成礦物質來源,如在贛南的石雷、粵北的梅子窩等鎢礦床可能有這種情況,在湘南的益將,加裏東期的石英閃長巖為風化殼型稀土-鈧礦化直接提供瞭成礦物質來源.(3)更為重要的是華南地區正是從加裏東期開始進入瞭陸內縯化的階段,加裏東期花崗巖類開啟瞭以地殼物質重鎔為主的華南大花崗巖省形成和髮展的重要一幕,標誌著華南陸殼進入不斷成熟、親石成礦元素不斷嚮陸殼富集的階段,多鏇迴花崗巖漿活動及其縯化使鎢錫等金屬元素在燕山期花崗巖中高度富集,併最終導緻瞭華南地區舉世矚目的燕山期大規模成礦作用.
화남가리동기적화강암류재강도화엄도상부차우연산기화강암,시화남대화강암성적중요조성부분.단시전인대우가리동기화강암류여성광관계적보도교소,조기적연구심지인위가리동기화강암일반불성광.본문근거대근년래재모사지구화광상출현적가리동기화강암류급상관광화현상적초보연구성과,병결합대상관문헌적조연,제출화남지구가리동기화강암류여해지구오석등금속대규모성광작용지간구유상당밀절적관계.저충관계주요표현재삼개방면:(1)모사가리동기화강암、우기시나사연화비교충분적가리동만기화강암가능재만계단직접형성광상,여상동남적팽공묘、계북적우당계、계동북적계령、우강지구적흠갑등화강암체,단시기중요성상대교소;(2)모사가리동기화강암가능위해지구교만기적성광작용제공부분성광물질래원,여재공남적석뢰、월북적매자와등오광상가능유저충정황,재상남적익장,가리동기적석영섬장암위풍화각형희토-항광화직접제공료성광물질래원.(3)경위중요적시화남지구정시종가리동기개시진입료륙내연화적계단,가리동기화강암류개계료이지각물질중용위주적화남대화강암성형성화발전적중요일막,표지착화남륙각진입불단성숙、친석성광원소불단향륙각부집적계단,다선회화강암장활동급기연화사오석등금속원소재연산기화강암중고도부집,병최종도치료화남지구거세촉목적연산기대규모성광작용.
The Caledonian granites take the second importance among the multi-aged granitoids in so-called South China Large Granite Province. However, the pervious studies show less concern on the metallogenic aspects of Caledonian granites. Some early studies considered no important mineralization related to Caledonian granites. Based on some newly discovered granitic intrusions of Caledonian ages, together with the synthetic assessment of related literature, the present paper reviews the general character of Caledonian granites and discusses the relationship between Caledonian granites and large scale rare metal metallogeneses in South China. Although the large-scale rare metal mineralization mainly took place in the Yanshanian Period of Late Jurassic Era, Caledonian granitoids of mostly Silurian Era made great positive effects. Some well-evolved Caledonian granites, such as those in Penggongmiao of southeastern Hunan, Niutangjie of northern Guangxi, Guiling of northeastern Guangxi, and Qingjie of Youjiang area, can cause W, Mo and Sn mineralization. Some others might serve as rare metal supply for mineralization associated with late-staged granites, such as Shilei of southern Jiangxi and Meiziwo of northern Guangdong. At Yijiang of southern Hunan, the weathering products of Caledonian quartz diorite form a unique REE-Sc deposit. The most important significance, however, is that the Caledonian Orogeny started the intra-continental crust evolution of South China. The Caledonian granitoids resulted mainly by melting of crust materials, instead of adding of mantle material. The following tectonic episodes such as Variscan, Indo-sinian, and Yanshanian, together with the accompanying granitic magmatism, promoted the forward evolution of crust. As a result, the crust of South China became highly matured, which is indicated by high enrichment of felsic components and lithophile rare metals, and finally yielded the largest rare metal mineralization in the world.