应我校科学研究院王水炯教授邀请,澳大利亚科廷大学William Collins 教授,将来我校进行学术交流,并做学术报告。 时间:2024年11月5日(星期二)上午9:30-11:30 地点:中国地质大学(北京)教四楼109 题目:Origin of Cordilleran Batholiths: An integrated Tectono-magmatic model 报告摘要: Petrological features of two iconic Cordilleran batholiths are reviewed: the Sierra Nevada Batholith (SNB) of USA and the Western Fiordland Orthogneiss (WFO) of New Zealand (NZ). The SNB is a cool transcrustal system where granitoids extend to the Moho and magmatic temperatures were consistently low; below 850oC. Field relations show that chemical variation resulted from hybridisation between cool, resident felsic magma and local mafic infusions. The WFO of NZ also extends to the Moho, but it was a hot mafic (50-60 wt% SiO2) system that crystallised at ~1000oC and 10 kbar as a Deep Crustal Hot Zone. Soon after emplacement, the WFO was cooled and buried to 50-60 km depth and underwent limited partial melting, which produced high Sr/Y felsic dykes at ~720oC and ~15 kbar during a period of flat subduction. The cool, hydrous P-T-t paths of both batholiths are compared with the Kohistan arc and a general tectonic model of flat subduction is developed to explain the generation and ascent of cool, hydrous to superhydrous, transcrustal batholithic systems, and removal of their eclogite-facies (arclogitic) roots.
报告人简介:威廉(比尔)·柯林斯在花岗岩的起源及其相关构造和地球动力学的方面拥有丰富的知识。他的主要研究包括西澳大利亚的太古宙皮尔巴拉克拉通、澳大利亚中部的元古代造山带,以及东澳大利亚和新西兰的古生代/中生代造山带。花岗岩中锆石Hf同位素系统如何在增生型和碰撞型造山带以及威尔逊和超大陆循环中演变。目前他研究的重点是幔源水控制弧岩浆活动和大陆形成中的作用。 研究生计学术报告一次,欢迎广大师生参加!
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