CAJ | 학술논문

伟晶岩是一种特殊的火成岩类,东秦岭是我国重要的花岗伟晶岩分布区和稀有金属成矿区之一,这里广泛发育各种类型花岗伟晶岩,并形成4个大的花岗伟晶岩脉密集区.岩石化学、稀土配分和氧同位素研究结果显示,东秦岭的花岗岩与伟晶岩具有一致或相似的特点.其粗大的矿物组成,表明伟晶岩中富含挥发份并且是在封闭条件较好的地壳中深部形成的,是地壳深部过程的记录和区域侵蚀深度较大的标志.各种类型的花岗伟晶岩具特征的结构、成分和矿化分带现象,反映出深部透岩浆流体的成矿作用.东秦岭花岗伟晶岩受秦岭造山带主造山阶段的加里东期板块俯冲碰撞的影响,是同一板块俯冲碰撞构造体制下由花岗岩母岩浆分异、演化的结果.东秦岭花岗伟晶岩分布面积大、类型全、分异演化强烈、矿化普遍,是我国寻找花岗伟晶岩型稀有元素矿产、铀矿和部分宝石资源的有利地区.
위정암시일충특수적화성암류,동진령시아국중요적화강위정암분포구화희유금속성광구지일,저리엄범발육각충류형화강위정암,병형성4개대적화강위정암맥밀집구.암석화학、희토배분화양동위소연구결과현시,동진령적화강암여위정암구유일치혹상사적특점.기조대적광물조성,표명위정암중부함휘발빈병차시재봉폐조건교호적지각중심부형성적,시지각심부과정적기록화구역침식심도교대적표지.각충류형적화강위정암구특정적결구、성분화광화분대현상,반영출심부투암장류체적성광작용.동진령화강위정암수진령조산대주조산계단적가리동기판괴부충팽당적영향,시동일판괴부충팽당구조체제하유화강암모암장분이、연화적결과.동진령화강위정암분포면적대、류형전、분이연화강렬、광화보편,시아국심조화강위정암형희유원소광산、유광화부분보석자원적유리지구.
Pegmatite is a special type of igneous rock. The eastern Qinling belt is one of the important granitic pegmatite distributions region and rare metal metallogenic provinces, where extensively crop out granitic pegmatite with different types and formed four pegmatite concentration zones. The studies on petrochemsitry, REE distribution patterns and oxygen isotopic compositions show that granite and pegmatite in the eastern Qinling belt possess the same or similar characteristics. And the coarse minerals indicate that pegmatite enrich fugitive constituent and be formed in deep crust under relatively enclosed conditions. Then it is deduced that pegmatite records the geologic processes in deep crust and is a signal of relatively deep regional erosion. Different types of pegmatite show typical horizontal zonation in composition, texture and metallogenesis, which reflects the tranmagmatic fluid metallogenesis. Based on those, it is suggested that the pegmatite and granite in the eastern Qinling belt are derived the differentiation and evolution of the same granitic magma source under the influence of Caledonian period plate subduction and collision in main stage of the Qinling orogeny. As a whole, the eastern Qinling belt is the potential metalogenic province of rare metal, U and some precious stone resources of granitic pegmatite type, because of the characteristics of grantic pegmatite with large distribution area, extensive type, intensive differentiation and evolution, and mineralization in the eastern Qinling belt.