Geodynamic evolution of the NE Gondwana margin in the area of the Pyrenees: Chronology of granitoid placements and their geochemical and structural signatures.

比利牛斯山脉地区冈瓦纳东北部边缘的地球动力学演化：花岗岩位置的年代学及其地球化学和结构特征。

• 批准号: 455876831
• 负责人: Dr. Stephan Schnapperelle
• 金额: --
• 依托单位: Museum für Mineralogie und Geologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/455876831?language=en
• 关键词: Geodynamic; evolution; NE; Gondwana; margin

The goal of the project is a model for the evolution of the (proto-) Pyrenees based on the genesis of granitoids in the context of the Variscan mountain formation in the Axial Zone of the Pyrenees. This should be integrated into the regional development of the Gondwana shelf area during the Variscan orogeny. In the context of the current discussions and reinterpretation of regional conditions during the Variscan orogeny new questions have arisen especially in the area of the Pyrenees. Thus, an application of the current models, such as magma formation exclusively in connection with subduction zones or by gravitational collapse of the orogeny is questionable (see discussion in Franke, 2014) and must be reworked and reinterpreted. More and more evidence for increased magmatic impulses is found, which supports the theory of an increased heat flux in the entire area of Gondwana's northern rim. These effects can also be found in other areas of the Variscan zone. In order to detect a possible pulsating mantle source and the associated increased heat flux in selected areas of the Variscan basement, the following main objectives are to be pursued in this project:(1) Magmatic pulses shall be identified by the evaluation of U-Th-Pb age spectra from zircons, including xenochrysts.Additionally, the age structures of the host rocks from which the original magma for the Variscan plutons was formed will be identified. (2) The identification of crustal levels of magma formation and identification of possible protoliths using a combination of REE signatures and Lu-Hf isotopes.(3) Modelling of the crustal development by creating model ages (Lu-Hf).(4) Temporal classification of the outgoing main Variscan deformation phase D2 in the Pyrenees by analysis of microstructures.(5) After interpretation of all data sets: Proof and model development of an influence of the TUZO mantle plume during the period of the Variscan orogeny in the area of the Pyrenees, respectively the Gondwana Northern margin.

该项目的目标是在比利牛斯山脉轴带华力西山脉形成背景下，根据花岗岩类的成因，建立比利牛斯山脉（原）演化模型。这应纳入华力西造山运动期间冈瓦纳大陆架地区的区域发展。在目前讨论和重新解释华力西造山运动期间的区域条件的背景下，特别是在比利牛斯山脉地区出现了新的问题。因此，当前模型的应用，如岩浆形成仅与俯冲带或造山带的重力塌陷有关，是值得怀疑的（见Franke，2014年的讨论），必须重新工作和重新解释。越来越多的证据表明，岩浆冲动增加，这支持了在冈瓦纳北方边缘的整个地区的热通量增加的理论。这些影响也可以在华力西地区的其他地区发现。为了探测华力西基底某些地区可能存在的脉动地幔源和与之相关的热通量增加，本项目的主要目标是：（1）通过评价锆石（包括异金）的U-Th-Pb年龄谱来确定岩浆脉动，此外，还将确定华力西岩体原始岩浆形成的寄主岩石的年龄结构。(2)结合稀土元素和Lu-Hf同位素特征，识别岩浆形成的地壳层次和可能的原岩。(3)通过建立模型年龄（Lu-Hf）模拟地壳发展。(4)通过显微结构分析对比利牛斯山脉中流出的主要华力西变形相D2进行时间分类。(5)所有数据集的解释后：证明和模型开发期间的比利牛斯山脉地区的华力西造山带的TUZO地幔柱的影响，分别冈瓦纳北方边缘。