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

与位于德国西南部和法国西南部的上莱茵地块伸展裂谷系统有关的地壳规模的流体流动，导致了许多非常年轻的热液成矿样式的形成。作为描述裂谷相关流体循环近期状态的活动温泉系统可用的水文和水化学数据和模型的补充，矿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重晶石-硫化物成矿作用的初步研究表明，热液活动持续时间延长，至少约为500 KYR。人们还注意到，位于莱茵河上地块肩部的华力西期后热液萤石-重晶石-方解石矿脉显示出明显的再动员作用，这可能与非常年轻的构造和热液活动有关。建议扩大调查范围，将莱茵河上游地块周围的不同矿化区包括在内。研究将涉及以下目标：(1)年轻矿化类型的矿物学和地球化学特征；(2)稳定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关联；(3)评估流体输入和分散相对于继承对元素重新分配的相对作用；(4)重建成矿过程中普遍存在的物理化学条件；(5)建立一致的年轻热液活动地质-地球化学模式。

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.