红石山地区印支期花岗岩位于甘肃北山地区的红石山蛇绿混杂岩带中,由马鞍山北岩体、小草湖岩体和红石山岩体组成,岩性主要为英云闪长岩、花岗闪长岩和二长花岗岩,含角闪质和镁铁质暗色深源包体。同位素年龄为237.8-240 M a,是中三叠世...红石山地区印支期花岗岩位于甘肃北山地区的红石山蛇绿混杂岩带中,由马鞍山北岩体、小草湖岩体和红石山岩体组成,岩性主要为英云闪长岩、花岗闪长岩和二长花岗岩,含角闪质和镁铁质暗色深源包体。同位素年龄为237.8-240 M a,是中三叠世侵位的。通过对其岩石化学、稀土和微量元素的研究表明,红石山地区印支期中酸性侵入岩大体可划分为两类：一类为高S r低Y型岩体（马鞍山岩体）,具有埃达克质岩的地球化学特征,推测可能是加厚的下地壳部分熔融形成的,其残留相为榴辉岩或角闪榴辉岩;另一类为低S r低Y型岩体（小草湖岩体和红石山岩体）,以较低的S r、A l和具明显的负铕异常而区别于埃达克质岩,又因其低Y和HREE而类似于埃达克质岩,推测源岩残留相中有斜长石存在,相当于高压麻粒岩相环境,可能也形成于加厚下地壳底部。展开更多
Geologists are paying more attention to studies on genesis of granitoids and their metallogenetic characteristics through tracing their source materials and geological evolution by means of strontium, neodymium and le...Geologists are paying more attention to studies on genesis of granitoids and their metallogenetic characteristics through tracing their source materials and geological evolution by means of strontium, neodymium and lead isotopes. However, using Sm-Nd isotopes to study source rocks of young granites, especially of the Mesozoic granites is not as effective as using Rb-Sr isotopes. In order to explain geological significance of isotopic studies, this note only makes use of Rb-Sr and Pb isotopes to investigate the source rocks of Guposhan granite complex which is a very important granite pluton of the Mesozoic era in South China.展开更多
基金Project supported by the National Natural Science Foundation of China.
文摘Geologists are paying more attention to studies on genesis of granitoids and their metallogenetic characteristics through tracing their source materials and geological evolution by means of strontium, neodymium and lead isotopes. However, using Sm-Nd isotopes to study source rocks of young granites, especially of the Mesozoic granites is not as effective as using Rb-Sr isotopes. In order to explain geological significance of isotopic studies, this note only makes use of Rb-Sr and Pb isotopes to investigate the source rocks of Guposhan granite complex which is a very important granite pluton of the Mesozoic era in South China.
