当前位置: X-MOL 学术Lithos › 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.)
Middle Paleoproterozoic tectonic evolution of the Trans-North China Orogen, North China Craton: Constraint from the intermediate-acid magmatism in the Lüliang area
Lithos ( IF 2.9 ) Pub Date : 2020-12-01 , DOI: 10.1016/j.lithos.2020.105804
Jiao Zhao , Chengli Zhang , Xinyu Liu , Jing Gan

Abstract The excellent middle-Paleoproterozoic tectono-thermal activities from the Luliang Complex can provide pivotal constraints on the tectonic evolution of the Trans-North China Orogen between Eastern and Western blocks of North China Craton. LA-ICP-MS zircon dating gives emplacement ages of 2189 ± 16 Ma for gneissic diorite, 2188 ± 11 Ma for gneissic quartz monzonite, 2153 ± 9 Ma for gneissic granite in Chijianling area, respectively. The gneissic diorites have high Al2O3 (15.89–16.69 wt%), MgO (3.35–4.96 wt%), low Sr/Y (11.3–16.6), (La/Yb)N (7.40–8.44), enrichment of LILE and depletion in HFSE, especially Nb, Ta, indicating partial melting of mantle wedge fluxed by the fluids. The gneissic quartz monzonites and gneissic granites belong to high K calc-alkaline and shoshonitic series and show right inclined REE patterns, consisting with I-type granite. Zircon Hf and whole-rock Nd isotopic compositions (eHf(t) = +0.1 to +5.3 and − 7.8 to −1.7; eNd(t) = −0.4 to +0.4 and − 1.8 to −0.6) of the gneissic quartz monzonites and gneissic granites are identical to those of dominant Neoarchean basement materials with addition of Mesoarchean vestiges to a certain extent. The diversity of source material (including continental and volcanic arc materials) resembles to magmatism in normal continental arc margins. The spatial distribution, rock assemblage and decreasing rock formation pressure further hint the tectonic transformation from compression to extension regime in local areas. Taking into account the prevalence magmatic records and contemporaneous deposition of middle-Paleoproterozoic in the Trans-North China Orogen, it suggests an active continental arc setting at ~2.2 Ga and local tectonic extension regime with back-arc basin at ~2.1 Ga for a consequence of the Paleoproterozoic subduction between the Eastern block and Western block of the NCC.

中文翻译:

华北克拉通横贯华北造山带中古元古代构造演化:吕梁地区中酸性岩浆作用的约束

摘要 吕梁杂岩中古元古代极好的构造热活动可以为华北克拉通东、西地块间横贯华北造山带的构造演化提供关键约束。LA-ICP-MS锆石测年给出的片麻岩闪长岩的侵位年龄分别为2189±16Ma,片麻石英二长岩的侵位年龄为2188±11Ma,赤尖岭地区片麻花岗岩的侵位年龄为2153±9Ma。片麻岩闪长岩具有高 Al2O3 (15.89–16.69 wt%)、MgO (3.35–4.96 wt%)、低 Sr/Y (11.3–16.6)、(La/Yb)N (7.40–8.44)、LILE 富集和耗尽在 HFSE 中,尤其是 Nb、Ta,表明被流体流动的地幔楔部分熔化。片麻石英二长岩和片麻花岗岩属于高钾钙碱性和钾长石系列,稀土元素向右倾斜,由I型花岗岩组成。片麻质石英二长岩的锆石 Hf 和全岩 Nd 同位素组成(eHf(t) = +0.1 至 +5.3 和 - 7.8 至 -1.7;eNd(t) = -0.4 至 +0.4 和 - 1.8 至 -0.6)片麻岩与占主导地位的新太古代基底物质相同,但在一定程度上增加了中太古代遗迹。源物质(包括大陆和火山弧物质)的多样性类似于正常大陆弧边缘的岩浆作用。空间分布、岩石组合和岩层压力降低进一步暗示了局部地区的构造从压缩向伸展的转变。考虑到横贯华北造山带中古元古代的盛行岩浆记录和同期沉积,表明在~2.
更新日期:2020-12-01
down
wechat
bug