The interplay between hydrothermal mineralizations and element redistribution processes related to young tectonic activity - case studies from SW Germany

位于德国和法国西南部的上莱茵地堑伸展裂谷系的地壳尺度流体流动导致了许多非常年轻的热液成矿样式的形成。作为对活跃温泉系统的水文和水化学数据和模型的补充，这些数据和模型表征了与裂谷有关的流体循环的最新状态，矿物化的地球化学和同位素研究为了解演化历史提供了一个令人兴奋的窗口。对威斯巴登温泉系统的重晶石硫化物矿化的初步研究表明，热液活动的持续时间至少延长了500 kyr。此外，上莱茵地堑肩部的后瓦里斯坎热液萤石-重晶石-方解石脉显示出明显的再活化迹象，这可能与非常年轻的构造和热液活动有关。建议将调查范围扩大到上莱茵地堑周围不同的矿化区。这项研究将探讨以下目标：(1)年轻成矿风格的矿物学和地球化学特征；(2)稳定同位素和放射性同位素趋势与流体混合或流体-岩石相互作用等过程的对比；(3)评价流体输入和分散与元素再分配的相对作用；(4)重建成矿形成过程中普遍存在的物理化学条件。(5)建立了一致的年轻热液活动地质-地球化学模型。

Crustal-scale fluid flow related to the extensional rift system of the Upper Rhine Graben, located in southwest Germany and France, has resulted in the formation of a number of very young hydrothermal mineralization styles. Complementary to hydrological and hydrochemical data and models available for active thermal spring systems, which characterize the recent state of rift-related fluid circulation, geochemical and isotopic studies of mineralizations provide an exciting window into the evolutionary history. Preliminary studies of barite-sulphide mineralization of the Wiesbaden thermal spring system point to a prolonged duration of hydrothermal activity on the order of at least 500 kyr. It has also been noted that post-Variscan hydrothermal fluorite-barite-calcite veins located on the shoulders of the Upper Rhine Graben show evidence of a pronounced remobilization, which can be related to very young tectonic and hydrothermal activity. It is proposed to expand the investigation to include different mineralized areas in the surroundings of the Upper Rhine Graben. The study will address the following objectives: (1) mineralogical and geochemical characterization of the young mineralization styles, (2) correlation of stable and radiogenic isotope trends with processes such as fluid mixing or fluid-rock interaction, (3) assessment of the relative role of fluid input and dispersion versus inheritance for element redistribution, (4) reconstruction of the physicochemical conditions prevalent during formation of the mineralization, and (5) development of a consistent geological-geochemical model of young hydrothermal activity.