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

与俯冲带相关的基性/超基性杂岩标志着南极洲北维多利亚地陆威尔逊地陆与鲍尔斯地陆之间的缝合线，这些杂岩非常适合于评价冈瓦纳古太平洋大陆活跃边缘寒武纪的岩浆和构造演化。其中之一是虎辉长岩杂岩（TGC），这是一个与寒武纪弧相关的层状基性杂岩，其特征是异常新鲜的岩石序列，包括超镁铁质和演化岩性，以及壮观的高温剪切带的存在。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活动的深部地壳序列的岩浆/构造/地质演化。第二个为期12个月的项目将侧重于对GANOVEX X考察期间由申请人之一（F. henje - kunst）收集的样品进行微观分析和块岩地球化学研究。对新样品进行的额外采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，这些新方面是在正在进行的KO 1723/11-1项目研究的前三个月出现的（见下文）。这些调查连同本项目第一阶段进行的工作将有助于更好地规划我们的长远目标，其中将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。与科希斯坦（巴基斯坦）的奇拉斯杂岩非常相似的岩石学特征，为全球对年轻岛弧下地壳增生的理解开辟了有趣的视角。

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.