当前位置: X-MOL 学术Polar Sci. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
P-T-t-d evolution of Brattnevet Peninsula, Larsemann Hills, East Antarctica
Polar Science ( IF 1.5 ) Pub Date : 2021-07-08 , DOI: 10.1016/j.polar.2021.100728
M.Y. Shah 1 , Mohammad Sadiq 2 , K.K. Ayemi 3 , A. Dharwadkar 2 , S.K. Roy 4
Affiliation  

Brattnevet Peninsula, Larsemann Hills, comprises metamorphosed acidic rocks, sedimentary rocks and basic igneous suite belonging to timespan of 920-478 Ma and have experienced three phases of deformation and metamorphism. The first and second phase of deformation gave rise to moderately plunging isoclinal and open to closed folds, respectively and the third phase resulted into broad warping. M1 prograde (amphibolite) and M2 peak (granulite) and M3 retrograde (decompression) events have been inferred. In pyroxene granulite, inclusion assemblage of quartz, biotite, plagioclase and ilmenite in hornblende correspond to the relict M1 amphibolite grade event associated with D1-D2 deformation events (occurred at ~920 Ma; 538–692 °C at ~6kb). However, the presence of enstatite, diopside, quartz, biotite, ilmenite and plagioclase in pyroxene granulite and sillimanite, biotite and almandine garnet and plagioclase in metapelite indicates granulite facies during M2 event (~530 Ma; 868–920 °C at ~6.7 kb). The retrograde M3 event (500-480 Ma; ~620 °C at ~5kb) is largely depicted in pyroxene granulite and metapelite by coronal and symplectite cooling textures. The study shows a clockwise P-T path and suggests the crustal evolution of Larsemann Hills area have commenced at the wanning stages of Grenvillian Orogeny and imprinted by the Pan-African orogenic event in the terrane.



中文翻译:

南极洲东部拉瑟曼山布拉特尼维特半岛的 PTtd 演化

拉瑟曼山布拉特尼维半岛由变质酸性岩、沉积岩和基性火成岩套组成,时间跨度为 920-478 Ma,经历了变形和变质三个阶段。变形的第一阶段和第二阶段分别导致中等倾斜的等斜和打开闭合褶皱,第三阶段导致广泛的翘曲。已经推断出M 1 前行(角闪岩)和 M 2峰(麻粒岩)和 M 3逆行(减压)事件。在辉石麻粒岩中,角闪石中石英、黑云母、斜长石和钛铁矿的包裹体组合对应于与 D 1 -D 2相关的残存 M 1角闪石品位事件变形事件(发生在~920 Ma;538-692 °C,~6kb)。然而,辉石麻粒岩中顽火辉石、透辉石、石英、黑云母、钛铁矿和斜长石的存在表明在 M 2事件期间(~530 Ma;868-920 °C at ~6. KB)。逆行 M 3事件(500-480 Ma;~620 °C,~5kb)主要通过日冕和辛辉岩冷却纹理在辉石麻粒岩和变泥质岩中描述。该研究显示了顺时针 PT 路径,并表明 Larsemann Hills 地区的地壳演化开始于 Grenvillian 造山运动的减弱阶段,并受到地体中泛非造山事件的影响。

更新日期:2021-07-08
down
wechat
bug