Pre-survey: Magmatic evolution of the Tiger gabbroic complex (Northern Victoria Land, Antarctica): insights into the lower crust of a Cambrian immature Island Arc

预调查：虎辉长岩杂岩体的岩浆演化（南极洲北维多利亚地）：深入了解寒武纪未成熟岛弧的下地壳

• 批准号: 130419963
• 负责人: Professor Dr. Jürgen Koepke
• 金额: --
• 依托单位: Bundesanstalt für Geowissenschaften und Rohstoffe (BGR)
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/130419963?language=en
• 关键词: Pre; survey; Magmatic; evolution; Tiger

Subduction-zone related mafic/ultramafic complexes marking the suture between the Wilson Terrane and the Bowers Terrane in Northern Victoria Land (Antarctica) are wellsuited for evaluating the magmatic and structural evolution at the active paleo-Pacific continent margin of Gondwana during the Cambrian. One of these intrusions is the Tiger Gabbro Complex (TGC), a Cambrian arc-related, layered mafic complex which is characterized by extraordinary fresh rock sequences including ultramafic and evolved lithologies and by the presence of spectacular high-temperature shear zones. It is our overall goal to establish the petrogenesis of the TGC in order to evaluate the magmatic/ structural/geological evolution of deep crustal sequences active during the Cambrian at the margin of Gondwana. The second 12-month project will focus on microanalytical and bulk rock geochemical studies on samples which will be collected during the GANOVEX X expedition by one of the applicants (F. Henjes-Kunst). Additional sampling and scientific investigations on the new samples should help to clarify important new aspects concerning the magmatic evolution of the complex, which emerged during the first three months of research in the ongoing project KO 1723/11-1 (see below). Together with the work performed during the first period of this project these investigations will serve to better plan our far-reaching goal which will include a comprehensive experimental study as well as detailed geochronological and isotope geochemical work. A very close petrographic similarity with the Chilas Complex in Kohistan (Pakistan), a world site for deep, juvenile arc crust, opens interesting perspectives for the global understanding of crustal accretion beneath young island arcs.

与俯冲带相关的镁铁质/超镁铁质杂岩标志着维多利亚北部地区（南极洲）威尔逊地体和鲍尔斯地体之间的缝合线，非常适合评估寒武纪时期冈瓦纳古大陆活跃古太平洋大陆边缘的岩浆和结构演化。其中一个侵入体是虎辉长岩杂岩体 (TGC)，它是一种与寒武纪弧相关的层状镁铁质杂岩体，其特征是异常的新鲜岩石序列，包括超镁铁质和演化岩性，以及存在壮观的高温剪切带。我们的总体目标是建立 TGC 的岩石成因，以评估冈瓦纳边缘寒武纪时期活跃的深部地壳序列的岩浆/结构/地质演化。第二个为期 12 个月的项目将重点对申请人之一（F. Henjes-Kunst）在 GANOVEX X 探险期间收集的样品进行微分析和大块岩石地球化学研究。对新样本的额外取样和科学调查应有助于澄清有关该复合体岩浆演化的重要新方面，这些方面是在正在进行的 KO 1723/11-1 项目（见下文）的前三个月研究中出现的。与该项目第一阶段进行的工作一起，这些调查将有助于更好地规划我们的深远目标，其中包括全面的实验研究以及详细的地质年代学和同位素地球化学工作。其岩石学特征与科希斯坦（巴基斯坦）的奇拉斯杂岩非常相似，这是一个深部年轻岛弧地壳的世界遗址，为全球了解年轻岛弧下的地壳增生提供了有趣的视角。