Detailed study of partial melting process in the island-arc type high-temperature metamorphic terrane

本研究项目的主要目的是详细研究岛弧型下地壳的部分熔融过程及其相关的花岗质岩浆生成系统，如日本高温变质带、日高变质带和日后变质带。并与典型的高温变质杂岩（斯里兰卡和南极洲纳皮耶杂岩）进行了对比。主要结果如下：1.在澳大利亚新南威尔士大学重新开始了氟-黑云母脱水熔融的实验工作。与无氟黑云母相比，高氟黑云母的稳定场向高温侧扩展。XF（F/（F+Cl+OH））=0.3的黑云母在900 MPa，1025 ℃下仍保持稳定，XF=0.6的黑云母在900 MPa，1075 ℃下稳定范围扩大。部分结果已在1995年9月在意大利举行的南极地球科学国际研讨会和中国国际地质大会（Au）上发表 ...更多信息 2.在九州中西部的Higo变质带进行了为期60天的野外研究。在1995年的野外工作中，在该岩体的中部发现了石榴石-橄榄麻粒岩和石榴-橄榄麻粒岩。这种类型的超铝硅不饱和麻粒岩仅见于美国Cortlandt杂岩的超高温捕虏体中。在Higo变质杂岩中，这些麻粒岩作为残留岩是由含氟黑云母（XF=0.2）变岩的高温（>950 ℃，800-1000 MPa）脱水熔融形成的。部分成果在日本地质学会等1996年年会上发表，并提交国际期刊。3.在日高变质带进行了为期60天的野外考察，观察了泥质和镁铁质变质岩部分熔融的细节。特别是在镁铁质变质岩中，斜长角闪岩的整体化学成分在南北带之间有明显的差异。部分结果发表在日本地质学会的回忆录中。少

The main purpose of this research project is the detailed study of partial melting process and their related granitic magma producing system in the island-arc type lower crust as seen the high-temperature metamorphic terrane in Japan, the Hidaka metamorphic belt and the Higo metamorphic terrane. The results were compared with the typical high-temperature metamorphic terranes (Sri Lanka and Napier Complex, Antarctica). Brief results are as follows.1.Restarted the experimental work for dehydration melting of fluorine-biotite at the University of New South Wales, Australia. The stability field of the high-fluorine biotite expands into higher temperature side than fluorine-free biotite. Biotite of XF (F/ (F+Cl+OH) )=0.3 is still stable at 900 MPa, 1025ﾟC and those of XF=0.6 the stability field expand up to 900 MPa, 1075ﾟC.A part of the results were reported at the International Symposium on Antarctic Earth Sciences in Italy (Sep, 1995) and the International Geological Congress in China (Au … More g, 1996).2.Sixty days field research was carried out in the Higo metamorphic terrane, west central Kyushu. During the field work in 1995, the sapphirine-corundum and the garnet-corundum granulites were found in the central part of the terrane. This type of hyper aluminous silica-undersaturated granulite is known only in very (ultra) high temperature xenolith of Cortlandt Complex, USA.In the Higo metamorphic terrane, those granulites as the restite were derived from high temperature (>950ﾟC at 800-1000 MPa) dehydration melting of fluorine biotite (XF=0.2) -bearing metapelite. A part of the results was talked at the 1996 annual meeting of the Geological Society of Japan etc. and submitted to international journal.3.Sixty days another field survey was carried out in the Hidaka metamorphic belt to observe the details of partial melting of pelitic and mafic metamorphic rocks. Especially in the mafic metamorphic rocks it was identified that the bulk chemical compositions of amphibolites are clearly different between the north and the south of the belt. A part of the results was reported in the Memoir of the Geological Society of Japan. Less