SHRIMP zircon age constraints from the Larsemann Hills region, Prydz Bay, for a late Mesoproterozoic to early Neoproterozoic tectono-thermal event in East Antarctica
SHRIMP zircon age constraints from the Larsemann Hills region, Prydz Bay, for a late Mesoproterozoic to early Neoproterozoic tectono-thermal event in East Antarctica
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普里兹湾拉尔斯曼山地区东南极洲中元古代晚期到新元古代早期构造热事件的 SHRIMP 锆石年龄限制
DOI：
10.2475/04.2008.07
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发表时间：
2008-04
影响因子：
2.9
通讯作者：
Chung Sun-lin
中科院分区：
文献类型：
--
作者：
Liu Dunyi;Ren Liudong;Wang Yanbin;Tong Laixi;Chung Sun-lin
本文报道了东南极普里兹湾拉斯曼丘陵麻粒岩相岩石的年代学研究。对长英质片麻岩、镁铁质片麻岩、副片麻岩、长英质片麻岩、花岗质片麻岩、浅粒片麻岩等14个样品进行了SHRIMP锆石年龄测定。这些年龄结果，结合锆石地球化学数据和阴极发光图像，使我们能够探索锆石的形态复杂性，记录多构造事件。例如，在所研究的三个长英质片麻岩样品中的锆石分离物中观察到了多个年龄分带的特征，这些样品含有ca. 1.13 Ga和Ca的变质地幔和边缘。1.0和0.53Ga。这表明在中元古代晚期有一个岩浆活动和地壳形成时期，在新元古代早期和早古生代分别有两个高级变质阶段。在其他岩石类型中也观察到类似的锆石过度生长现象。虽然早古生代构造活动一直被认为是南极地壳演化中最重要的，我们的研究提供了第一个令人信服的年龄证据，存在一个晚中元古代移动的带。CA。1.0 Ga变质记录保存在不同的岩石从研究区进一步支持了一个连续的环东南极晚中元古代（格伦维尔时代）造山带的建议。在这个框架内，Pradizz湾造山带被认为位于Rodinia组合的中心部分，该组合将印度的东高止山脉与南极洲在约1000年结合在一起。1.0佐治亚州
This paper reports a geochronological study of granulite-facies rocks from the Larsemann Hills of Prydz Bay, East Antarctica. SHRIMP zircon ages were obtained for a total of 14 samples that cover various rock types including felsic gneiss, mafic gneiss, paragneiss, enderbite, granitic gneiss and leucogneiss. These age results, combined with zircon geochemical data and cathodoluminescence images, enable us to explore the morphological complexity in zircons that record polytectonic events. Features of multiple age zoning, for example, were observed in zircon separates from three felsic gneiss samples studied, which contain magmatic cores of ca. 1.13 Ga and metamorphic mantles and rims of ca. 1.0 and 0.53 Ga, respectively. This suggests a period of magmatism and crust formation in the late Mesoproterozoic and two subsequent phases of high-grade metamorphism during the early Neoproterozoic and early Paleozoic, respectively. Similar phenomena of zircon overgrowth were also observed in other rock types. Although early Paleozoic tectonic activity has been considered as most significant in Antarctic crustal evolution, our study provides the first convincing age evidence for the existence of a Prydz Bay late Mesoproterozoic mobile belt. The ca. 1.0 Ga metamorphic record preserved in diverse rocks from the study area furthermore supports the proposal of a continuous circum East Antarctica late Mesoproterozoic (Grenville-age) orogenic belt. Within this framework, the Prydz Bay orogen is proposed to have been located in the central part of the Rodinia assembly that brought the Eastern Ghats of India together with Antarctica at ca. 1.0 Ga.
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影响因子：
3.8
作者：
S. Boger
通讯作者：
S. Boger
影响因子：
3.4
作者：
K. Stüwe;R. Powell
通讯作者：
K. Stüwe;R. Powell
影响因子：
5.8
作者：
R. Larson
通讯作者：
R. Larson
影响因子：
3.8
作者：
D. Young;Jian-xin Zhao;D. Ellis;M. McCulloch
通讯作者：
D. Young;Jian-xin Zhao;D. Ellis;M. McCulloch
影响因子：
2.3
作者：
I. Fitzsimons
通讯作者：
I. Fitzsimons