摘要
实验证明雪峰期含锡黑云母花岗岩是由元石宙四堡群变质岩在５００＾１０＾５－２０００×１０＾５Ｐａ的压力和７５０－５７０℃的温度范围内，经过重熔再结晶而成，而且进一步证实含Ｆ和Ｂ的水溶液对降低成岩的温度起了重要的作用。实验的结果与野外实际情况相符，揭示了含锡黑云母花岗岩形成的机理，阐明了它的形成在中国南方地壳动力学上的意义。
The authors intensively studied natural granites and metamorphic rocks of the Sibao Group in northern Guangxi, and found the genetic relation between Xuefengian Sn-bearing granite and Sibao'an metamorphic rocks in many macroscopic and microscopic respects through observations of field geology, study of the remains for melted metamorphic rocks, comparison of the mineralogy, petrological chemistry, trace elements, rare earth elements in granites with those in wallrocks, isotopic analysis of granites and calculation of partial melting formula. On that basis experiments of rock formation were performed.All experiments were carried out in instruments of quick quenching at high temperatures and high pressures. Experimental samples were those collected from natural metamorphic rocks in northwestern Guangxi and the mixtures prepared by chemical reagents according to the chemical compositions of the metamorphic rocks of the Sibao Group, which contained a little water. Experimental products were studied under the microscope and by X-ray.Experimental results proved that Xuefengian Sn-bearing granites in northern Guangxi are formed by melting of the Proterozoic metamorphic rocks of the Sibao Group at(500--2000) × 10~5Pa and 750--575℃. The results of experiments tally with the reality of the field geology. The authors have brought to light the mechanism of the formation of Sn-bearing granites, and expounded its significance in the crust dynamics of South China.
出处
《地质学报》
EI
CAS
CSCD
北大核心
1993年第4期336-347,共12页
Acta Geologica Sinica
基金
广西地矿局定向基金
关键词
锡
花岗岩
形成机理
experimental study, Sn-bearing granite, formation mechanism, northern Guangxi
