The third dimension of the ultramafic-hosted Logatchev-1 hydrothermal field: sulfide formation, evolution, and fluid flow in the subseafloor

该项目的总体目标是首次确定超镁铁质环境下海底热液矿化的范围和变异性。我们将使用英国地质调查局（British Geological Survey）远程操作的Rockdrill 2，从位于大西洋中脊（Mid-Atlantic Ridge）北纬14°45°的Logatchev-1热液区采集15米长的岩心样本。热液沉淀物和矿化岩石的地球化学、矿物学和同位素研究将有助于回答以下主要科学问题：矿化的大小和垂直范围是什么？在深部可能的分带模式是什么？2. 冒烟的火山口环境与典型的土丘式硫化物矿床有何区别？3. 浅层地下混合/冷却过程的本质是什么？这些过程如何影响喷口流体和可能的动物组合？（与其他工作组合作）幕式热液活动和再活化过程对矿床内金属的收支和分布有何影响？

The overall goal of this project is to establish, for the first time, the subseafloor extent and variability of hydrothermal mineralization in an ultramafic environment. We will use the remotely operated Rockdrill 2 of the British Geological Survey to sample 15 m long cores from the active Logatchev-1 hydrothermal field located at 14°45 N on the Mid-Atlantic Ridge. Geochemical, mineralogical, and isotopic investigations of hydrothermal precipitates and mineralized rocks will help to answer the following main scientific questions: 1. What is the size and vertical extent of mineralization and what are possible zonation patterns at depth? 2. What distinguishes the smoking crater environment from typical mound-style sulfide deposits? 3. What is the nature of mixing/cooling processes in the shallow subsurface and how do these processes influence the vent fluids and possibly the faunal assemblages? (in cooperation with other working groups) 4. What is the influence of episodic hydrothermal activity and remobilization processes on the metal budget and distribution within this deposit?