Generation and modification of large-scale post-tectonic batholiths (Donkerhuk granite; Namibia): Incremental growth vs in-situ differentiation

大规模后构造岩基（Donkerhuk 花岗岩；纳米比亚）的生成和改造：增量生长与原位分异

基本信息

批准号：
339361994
负责人：
Professor Dr. Stefan Jung
金额：
--
依托单位：
Mineralogisch-Petrographisches Institut (MPI)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2016
资助国家：
德国
起止时间：
2015-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/339361994?language=en
关键词：
Generation modification large scale post

项目摘要

The proposed project deals with the major and trace element and radiogenic isotope (Sr, Nd, Pb; the latter obtained on acid-leached Kfs) composition of a large-scale apparently undeformed post-tectonic granite in Namibia; the Donkerhuk granite. Available data are incomplete but published major and trace element variations suggest that the various subtypes of granite may have originated from distinct sources and evolved through different processes. On the other hand, the possibility exists that the various subtypes resulted from in-situ differentiation of larger isolated magma batches. The new results will place constraints on possible heterogeneities of the crustal structure beneath the adjacent southern and central Damara orogen and can be used to distinguish second-order processes (e.g., crustal contamination with or without fractional crystallization, magma mixing?) from first-order processes (e.g., partial melting of diverse crustal sources, coupled crust-mantle evolution). The project aims at understanding complex crustal processes at a time where pre-existing continental crust is re-organized and re-processed. These igneous processes are fingerprints of the dynamic melting of diverese crustal sources and is therefore ideally suited to add knowledge on crustal dynamics in general.

拟议项目研究纳米比亚一块明显未变形的构造后花岗岩的主量元素和微量元素以及放射性同位素（Sr、Nd、Pb；后者通过酸浸 Kfs 获得）组成；东克胡克花岗岩。现有数据不完整，但已发表的主量元素和微量元素变化表明，花岗岩的各种亚型可能起源于不同的来源，并通过不同的过程演化。另一方面，存在各种亚型是由较大的孤立岩浆批次的原位分化产生的可能性。新结果将对邻近的南部和中部达马拉造山带下方地壳结构可能的异质性施加限制，并可用于区分二级过程（例如，有或没有分步结晶的地壳污染、岩浆混合？）与一级过程过程（例如，不同地壳来源的部分熔融、耦合的壳幔演化）。该项目旨在了解先前存在的大陆地壳被重新组织和重新加工时的复杂地壳过程。这些火成岩过程是不同地壳来源动态融化的指纹，因此非常适合增加一般地壳动力学知识。