摘要
阿尔泰造山带存在晚古生代斜长 -二长花岗质片麻岩 ,与中级变质岩系相伴生 ,发育十分复杂的深层次褶皱或韧性剪切变形。斜长 -二长花岗质片麻岩的主体矿物组成为 :角闪石、黑云母、长石和石英 ,含有自形的绿帘石、锆石、磷灰石、环带状构造的褐帘石等副矿物。是一套相当于大陆边缘同构造环境的铝中等饱和的英云闪长质 -花岗闪长质 -二长花岗质系列的正变质岩系。钕模式年龄在 14 0 0 Ma～ 180 0 Ma,εNd(t)为正值 ,反映斜长-二长花岗质片麻岩源于年青地壳 ,并不是前寒武纪结晶基底 ,结晶成岩作用和变质变形作用几乎是同时发生的 ,年龄为 35 5 Ma± 5
Late Paleozoic plagio-monzonitic granitic gneiss with complex deeplevel folds or ductile deformation in Altai orogen belt is associated with the middle grade of metamoprphic rock series.Plagio-monzonitic granitic gneisses are mainly composed of hornblende, biotite, feldspar and quartz with abundant euhedral epidote, zircon, apatite and zonal allanite as accessory minerals,and belong to a suit of orthometamorphic rocks of tonalitic-granodioritic granodioritic and monzonitic composition, characteristic of continental margin peraluminous.granites. Nd model age ranges from 1 400 Ma to 1 800 Ma with positive ε Nd(t) values, suggesting that plagio-monzonitic granitic gneisses are derived from juvenile crust,instead of from precambrian crystalline basement.Crystallization,lithogenesis,metamorphism and deformation took place simultaneously at 355 Ma±5 Ma.
出处
《矿物岩石》
CAS
CSCD
北大核心
2003年第2期1-5,共5页
Mineralogy and Petrology
基金
国家新疆 3 0 5项目 (编号 :96-915 -0 2 -0 1)
教育部博士点基金项目 (编号 :2 0 0 10 183 0 0 8)
2 0 0 2年吉林大学青年基金
