摘要
澳大利亚西缘的平贾拉造山带遭受了格林维尔期和泛非期两期高级构造热事件的影响,其构造演化过程与罗迪尼亚超大陆的聚散和冈瓦纳超大陆的拼合密切相关。本文系统总结和评述了平贾拉造山带在中元古代–早古生代期间经历的三期主要地质事件及其构造意义,并与东南极雷纳造山带的地质事件进行了对比研究。平贾拉造山带中记录的三期主要地质事件包括:(1)中元古代晚期岩浆/变质事件(1090—1020 Ma),与全球格林维尔期造山作用有关,但对其详细的构造含义争议较大;(2)新元古代中期岩浆事件(780—660 Ma),具有伸展/裂谷岩浆作用特征,可能与罗迪尼亚超大陆的裂解有关;(3)新元古代晚期–早古生代(即泛非期)岩浆/变质事件(540—520 Ma),与东冈瓦纳大陆的聚合有关。地质对比研究表明,平贾拉造山带与东南极雷纳造山带所记录的中–新元古代地质事件存在明显的差别,两者不能连成一个统一的格林维尔期造山带。平贾拉造山带与普里兹湾地区的雷纳造山带部分(即普里兹造山带)都遭受到新元古代晚期–早古生代构造热事件的强烈改造,两者可能存在内在的联系。但是,普里兹湾地区新元古代中期岩浆事件的缺失表明两者可能还不能直接相连。因此,关于西澳平贾拉造山带向东南极的延伸问题尚存争议,这也是今后需要进一步研究的方向。
The Pinjarra Orogen at the western margin of West Australia has experienced Grenvillian and Pan-African high-grade metamorphism.The tectonic evolution of the orogen is closely related to the amal-gamation and breakup of the supercontinent Rodinia and the subsequent formation of the supercontinent Gondwana.This paper summarizes and reviews three major geological events of the Pinjarra Orogen during the Mesoproterozoic–early Paleozoic and discusses their correlations with geological events in the Rayner Orogen of East Antarctica.The three major geological events in the Pinjarra Orogen include:(1)a late Mesoproterozoic magmatic/metamorphic event(1090–1020 Ma),which is related to the global Grenvillian Orogeny with a controversial detailed tectonic setting;(2)a mid-Neoproterozoic magmatic event(780–660 Ma),which has attributes of extension/rifting magmatism and is probably related to the breakup of Rodinia;(3)a late Neoproterozoic–early Paleozoic(i.e.,Pan-African)geological event(540–520 Ma),which is related to the assembly of East Gondwana.Comparative studies show some differences in the Mesopro-terozoic–early Paleozoic geological events between the Pinjarra Orogen and the Rayner Orogen,indicating that these two belts could not have been directly connected into a unified Grenvillian orogenic belt.The Pinjarra Orogen and the intensively reworked Rayner Orogen in Prydz Bay(i.e.,the Prydz Belt)underwent a similar late Neoproterozoic–early Paleozoic orogenic event,implying a certain relationship between them.However,the absence of a mid-Neoproterozoic magmatic event in Prydz Bay suggests that these two belts also could not have been directly connected.Therefore,the continuation of the Pinjarra Orogen into East Antarctica still remains controversial,and further investigation into this issue is required.
作者
于世航
陈龙耀
刘晓春
Yu Shihang;Chen Longyao;Liu Xiaochun(Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;School of Earth and Space Sciences,Peking University,Beijing 100871,China;Laboratory of Paleomagnetism and Tectonic Reconstruction,Ministry of Natural Resources,Beijing 100081,China)
出处
《极地研究》
CAS
CSCD
北大核心
2021年第2期183-197,共15页
Chinese Journal of Polar Research
基金
国家自然科学基金(41530209、41941004、41802064)
中国地质调查局中国地质科学院基本科研业务费(JYYWF201819、DZLXJK202003)
中国地质调查局地质调查项目(DD20190579)资助。
关键词
格林维尔期
泛非期
地质事件
平贾拉造山带
西澳
东南极
雷纳造山带
Grenvillian
Pan-African
geological event
Pinjarra Orogen
West Australia
East Antarctica
Rayner Orogen
