Time scales for vertically moving axial magma chambers at fast-spreading ocean ridges and involved magmatic reactions: Insights from IODP Site 1256

快速扩张的洋脊上垂直移动的轴向岩浆室的时间尺度以及涉及的岩浆反应：来自 IODP Site 1256 的见解

基本信息

批准号：
143034347
负责人：
Professor Dr. Jürgen Koepke
金额：
--
依托单位：
Institut für Mineralogie
依托单位国家：
德国
项目类别：
Infrastructure Priority Programmes
财政年份：
2009
资助国家：
德国
起止时间：
2008-12-31 至 2014-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/143034347?language=en
关键词：
Time scales vertically moving axial

项目摘要

Models on the geodynamics of oceanic spreading centers imply that the axial magma chambers (AMC) under fast-spreading ridges are transient phenomena, moving up and down in distinct time scales which are only poorly quantified up to now. Thanks to IODP multi-cruise mission "Superfast Spreading Crust" (Site 1256, equatorial East Pacific Rise), a direct estimation of these time scales seems now possible. Expedition 312 drilled successfully a fossil conductive boundary layer (CBL): a horizon of metamorphosed, "granoblastic" dikes sandwiched between gabbros and sheeted dikes, providing the potential to obtain fundamental temporal information of the movements of the AMC/Dike transition. By applying modern tools of diffusion modeling to those phases within the "granoblastic" dike horizon, which were metamorphosed by the thermal imprint of the AMC in a high position, we aim to constrain the time scales of vertical movements of AMC's. During upward moving of an AMC into previously hydrothermalized dikes, vast reactions are expected causing assimilation and stoping. It is our attempt to simulate these processes experimentally, in order to understand/quantify the mechanism of the corresponding magmatic reactions for evaluation a general model, how contamination of MORB under fast-spreading ridges proceeds.

海洋传播中心地球动能学上的模型表明，快速扩张的山脊下的轴向岩浆腔（AMC）是短暂的现象，以不同的时间尺度上下移动，直到现在仅量化很差。得益于IODP多裁判任务“超快扩散地壳”（网站1256，赤道东太平洋崛起），对这些时间尺度的直接估算似乎是可能的。 Expedition 312成功地钻了一个化石导电边界层（CBL）：夹在Gabbros和板堤之间的变形，“粒细胞”的地平线，从而有可能获得AMC/Dike Truntition的运动的基本时间信息。通过将现代扩散建模工具应用于“粒细胞”堤期内的这些阶段，该阶段是由AMC的热烙印在很高位置变化的，我们旨在限制AMC垂直运动的时间尺度。在将AMC向上移动到先前的水热堤防过程中，预计会导致同化和停止。我们试图通过实验模拟这些过程，以理解/量化相应的岩浆反应的机制以进行评估，以评估通用模型，如何进行快速扩张的山脊下的MORB污染。