Phase Equilibria of Hornblende-Bearing Eclogite in the Western Dabie Mountain,Central China

来源 :Acta Geologica Sinica(English Edition) | 被引量 : 0次 | 上传用户:yangwenping666
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The high-pressure (HP) eclogite in the western Dabie Mountain encloses numerous hornblendes,mostly barroisite.Opinions on the peak metamorphic P-T condition,PT path and mineral paragenesis of it are still in dispute.Generally,HP eclogite involves garnet,omphacite, hornblendes and quartz,with or without glaucophane,zoisite and phengite.The garnet has compositional zoning with X_(Mg) increase,X_(Ca) and X_(Mn) decrease from core to rim,which indicates a progressive metamorphism.The phase equilibria of the HP eclogite modeled by the P-T pseudosection method developed recently showed the following:(1) the growth zonation of garnet records a progressive metamorphic PT path from pre-peak condition of 1.9-2.1 GPa at 508℃-514℃to a peak one of 2.3-2.5 GPa at 528℃-531℃for the HP eclogite;(2) the peak mineral assemblage is garnet+omphacite+glaucophane+quartz±phengite,likely paragenetic with lawsonite;(3) the extensive hornblendes derive mainly from glaucophane,partial omphacite and even a little garnet due to the decompression with some heating during the post-peak stage,mostly representing the conditions of about 1.4-1.6 GPa and 580℃-640℃,and their growth is favored by the dehydration of lawsonite into zoisite or epidote,but most of the garnet,omphacite or phengite in the HP eclogite still preserve their compositions at peak condition,and they are not obviously equilibrious with the hornblendes. The high-pressure (HP) eclogite in the western Dabie Mountain encloses numerous hornblendes, mostly barroisite. Opinions on the peak metamorphic PT condition, PT path and mineral paragenesis of it are still in dispute. Generally, HP eclogite involves garnet, omphacite, hornblendes and quartz, with or without glaucophane, zoisite and phengite.The garnet has compositional zoning with X_ (Mg) increase, X_ (Ca) and X_ (Mn) decrease from core to rim, which indicates a progressive metamorphism. the phase equilibria of the HP eclogite modeled by the PT pseudosection method showed recently following the following: (1) the growth zonation of garnet records a progressive metamorphic PT path from pre-peak condition of 1.9-2.1 GPa at 508 ° C -514 ° C to a peak one of 2.3 -2.5 GPa at 528-531 ° C for the HP eclogite; (2) the peak mineral assemblage is garnet + omphacite + glaucophane + quartz ± phengite, likely paragenetic with lawsonite; (3) the extensive hornblendes derive mainly from glaucophane, partial omphacite and even a little garnet due to the decompression with some heating during the post-peak stage, mostly representing the conditions of about 1.4-1.6 GPa and 580-640 ° C., and their growth is favored by the dehydration of lawsonite into zoisite or epidote, but most of the garnet, omphacite or phengite in the HP eclogite still preserve their compositions at peak condition, and they are not aware equilibrious with the hornblendes.
其他文献
在互联网络飞速发展的今天,各种文化充斥着人们的生活,形成了文化怪圈,从而唤起了人们对经典著作的需求,如何在新形势下进行经典阅读是当代图书馆的重要职责。 Today, with
阅读既能熏陶学生情操又能提高学生自我素养,一直以来,阅读推广都是高校图书馆的主要任务。自新媒体阅读出现后,高校学生的阅读方式与习惯逐之受到影响与改变,并给高校图书馆
中国关于菲律宾所提南海仲裁案管辖权问题的立场文件被国内有关学者认为是阐述中国南海政策的权威性文件。然而,该文件的起草者,由于缺乏对1982年《联合国海洋法公约》精神和
数码时代为摄影技术的飞跃提供了技术与社会环境,一方面摄影在平面设计中的地位日益重要,另一方面我国平面设计专业的摄影教学尚沿袭着传统美术教育的教学模式而缺乏更多的变
2010年6月21日至25日,国际海事组织在马尼拉大会,审议并通过了STCW公约马尼拉修正案及部分决议。该修正案对航海教育提出了新的要求,在该修正案的影响下,国内的航海教育面临
1996年9月,西安电影制片厂研究员、摄影家柏雨果独闯非洲。非洲以44℃的高温热情地欢迎他,在三个多月里,他跨越了交通、语言、饮食起居等方面的障碍,把非洲部落风情浓缩在胶
去年深秋,保定市文化局举办了“保定市稀有地方剧种展览演出”。参加展演的剧种有哈哈腔(《斗洛阳》“赶路”一折)、横岐调 (《调寇》)、新颖调(《志同道合》)、丝弦(《冯茂
1999年10月21日,天津《今晚报》刊有沙叶新《胖的权利》一文。从标题到文字,一如沙先生的一贯行文风格,挥洒自如,妙趣横生,只是有一处,似乎有点经不起推敲。沙先生说他在国
SMTA(Surface mount Technology Association)是一个全球性的表面贴装技术协会。SMTA组织一年一次的 SMTA (Surface Mount Technology Association) is a global surface mo
即 实 著      辽宁民族出版社版  即实,即辽宁省社会科学院历史研究所前所长、研究员巴图。巴图系辽宁省契丹文专家。中国古文字中契丹、女真、西夏三文,最难解读