西南印度洋龙旂、断桥热液区沉积物中重矿物空间分布特征及其意义

以中国大洋第34航次在西南印度洋龙旂与断桥热液区采集的洋底表层沉积物样品为研究对象,为洋中脊热液硫化物勘查重砂找矿工作提供一定的理论与工作基础,开展了沉积物自然重砂矿物的相关研究。绘制了研究区重砂矿物分布图,并根据研究区已探明热液矿体(喷口)的位置,对沉积物重分散晕的形成与分布规律进行了分析;从研究区沉积物的34种矿物中,筛选出3种沉积物重砂找矿的指示性矿物(重砂总量、黄铜矿、黄铁矿)及5种参考性矿物指标(帘石类矿物、透闪石、磁铁矿、铬铁矿、钛铁矿);运用统计学方法,建立了沉积物中指标矿物含量与矿源距离之间的线性方程,提出了根据测站沉积物中指标矿物含量,初步推算矿源距离的方法。

Heavy-mineralogical distribution characteristics of seafloor sediments from Longqi and Duanqiao hydrothermal fields in Southwest Indian Ridge and their geological inferences

Longqi and Duanqiao hydrothermal fields seafloor sediments of the Chinese research cruise 34 were investigated in this study. According to the proven hydrothermal orebody (spout) in the study area, the formation and distribution of the thick sand and scattering haloes in the sediments were analyzed. Among the 34 minerals in the sediments of the study area, three minerals (heavy sand, chalcopyrite, and pyrite) and five reference minerals (sedimentary minerals, tremolite, magnetite, chromite, and Ilmenite) were confirmed. Using statistical methods, a linear equation to indicate the mineral content of the sediments and source distance was established, and a method is proposed for predicting the source distance based on the mineral content in sediments.