Genesis of the Navachab Gold Deposit, Namibia

纳米比亚纳瓦查布金矿的成因

• 批准号: 23528250
• 负责人: Professor Dr. Franz Michael Meyer
• 金额: --
• 依托单位: Institut für Geologie, Mineralogie und Geophysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/23528250?language=en
• 关键词: Genesis; Navachab; Gold; Deposit; Namibia

The Navachab gold deposit in the Southern Central Zone of the Damara Orogen, Namibia, is situated within marbles, calc-silicate rocks and metapelitic schists of the Damara sequence. The mine is currently the only known lode-gold deposit in the extensive system of Pan-African orogenic belts in southern Africa. The deposit has experienced multiple episodes of high-T fluid-rock interaction during compressive deformation, that resulted in the formation of massive ¿replacement style¿ ore bodies, as well as several generations of quartz-sulfide veins. This study will examine the stable isotope and geochemical effects of superimposed fluid-rock interaction in this sediment-hosted lode-gold deposit. An isotopic tracer study on a continuous section from the unaltered host rocks through one of the ore bodies and representative quartz-sulphide veins will be undertaken in order to quantify the isotopic exchange between the ore-forming fluids and carbonaceous host rocks. In combination with fluid inclusion work (including in-situ chemical analyses of the fluid content), the results will provide new insights into the controls on hydrothermal fluid compositions, and the dynamics of this metamorphic (and magmatic?) hydrothermal system in a typical high-T, low-P metamorphic terrain.

纳米比亚达马拉造山带南部中心地带的Navachab金存款位于达马拉序列的大理石、钙硅酸盐岩和变绿片岩中。该矿是目前已知的南部非洲泛非造山带系统中唯一的矿脉金存款。该存款在挤压变形过程中经历了多期高温流体-岩石相互作用，形成了块状交代型矿体和多代石英硫化物脉。本研究将探讨该沉积岩型脉状金存款矿床的稳定同位素和叠加流体-岩石相互作用的地球化学效应。将对从未蚀变的容矿岩到其中一个矿体和代表性石英硫化物脉的连续剖面进行同位素示踪研究，以量化成矿流体与碳质容矿岩之间的同位素交换。结合流体包裹体工作（包括流体含量的原位化学分析），结果将提供新的见解热液流体成分的控制，和动力学的变质（和岩浆？）一个典型的高温低磷变质地体中的热液系统。