Understanding the Neoproterozoic geodynamics of NW India: clues from tectonomagmatic studies of the Cryogenian Sindreth Basin at the eastern Malani Igneous Province

了解印度西北部新元古代地球动力学：来自马拉尼火成岩省东部成冰纪辛德雷盆地构造岩浆学研究的线索

• 批准号: 278247024
• 负责人: Professorin Dr. Helga de Wall
• 金额: --
• 依托单位: Arbeitsgruppe Strukturgeologie und Tektonik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/278247024?language=en
• 关键词: Understanding; Neoproterozoic; geodynamics; NW; India

The Sindreth basin in NW India can be regarded as archive for the multiphase pulses of bimodal volcano-plutonic melts representing a characteristic feature of the c. 20 Ma lasting Malani magmatic activity. The Neoproterozoic Malani Igneous Suite (MIS) in NW India along with analogous magmatic rocks from the adjoining Nagarparkar region in SE Pakistan can be classified as a Silicic Large Igneous Province (SLIP). This magmatic event includes predominant felsic volcanism, granite emplacement and felsic and mafic dyke intrusions. Felsic rocks have typical A-type affinity originated from high temperature melting with major crustal input. It has been evaluated during the first project phase that mafic volcanics and dykes of the bimodal suite show geochemical homogeneity and derivation from a depleted continental mantle source without significant crustal contamination. In this second project phase we will study the geochemical and radiogenic isotope composition of the mafic rocks in order to determine (1) their relation to the felsic MIS rocks, (2) the mantle source(s) of the dykes, (3) the possible contamination with crustal rocks of different tectonic blocks, and (4) the potential origin from melting of subcontinental lithospheric mantle that could be similar to the 65-million-year-old Deccan flood basalts. The geochemical study will thus provide insight into the origin of the large volumes of magmas of the MIS and on the structure and composition of the lithosphere at the boundary between the Marwar and Aravalli Cratons.

印度西北部的Sindreth盆地可以被视为双峰式火山-深成岩熔体多相脉冲的档案，代表了C。20 Ma持续的马拉尼岩浆活动。位于印度西北部的新元古代马拉尼火成岩套（MIS）沿着邻近的巴基斯坦东南部纳加尔帕克地区的类似岩浆岩一起可被归类为硅质大火成岩省（SLIP）。该岩浆事件包括主要的长英质火山作用、花岗岩侵位和长英质和基性岩墙侵入。长英质岩石具有典型的A型亲合性，起源于高温熔融，主要由地壳输入。在项目第一阶段，已对双峰套的基性火山岩和岩墙进行了评价，表明其地球化学均一性，并源自贫化大陆地幔源，无显著地壳污染。在第二个项目阶段，我们将研究镁铁质岩石的地球化学和放射成因同位素组成，以确定（1）它们与长英质MIS岩石的关系，（2）岩墙的地幔来源，（3）可能与不同构造块体的地壳岩石混染，（4）与6500万年前的德干溢流玄武岩相似，可能起源于大陆岩石圈地幔的熔融。因此，地球化学研究将有助于深入了解MIS大量岩浆的起源以及Marwar和Aravalli火山之间边界岩石圈的结构和组成。

项目成果

Continental rift-setting and evolution of Neoproterozoic Sindreth Basin in NW-India

• DOI: 10.1007/s12040-017-0855-6
• 发表时间: 2017-09
• 期刊: Journal of Earth System Science
• 影响因子: 1.9
• 作者: S. Schöbel;K. K. Sharma-K.;Thorsten Hörbrand;Theresa Böhm;Ines Donhauser;H. Wall

Evolution and tectonic setting of the Malani – Nagarparkar Igneous Suite: A Neoproterozoic Silicic-dominated Large Igneous Province in NW India-SE Pakistan

• DOI: 10.1016/j.jseaes.2018.04.016
• 发表时间: 2018-07
• 期刊: Journal of Asian Earth Sciences
• 影响因子: 3
• 作者: H. de Wall;M. Pandit;Ines Donhauser;S. Schöbel;Wei Wang;K. K. Sharma-K.