Microbial controls on metal ion mobility

Abstract

In this dissertation, the biogeochemical controls on metal mobility in the subsurface are examined; specifically, the release of metals from buried mineralization, the transport of metals through overburden, and the sequestration of metals in soil. Field investigations were carried out to determine the relevant microbial ecology in direct proximity to and in soil overlying a buried volcanogenic massive sulfide (VMS) Cu-Zn deposit, and column experiments were completed to examine the biogeochemical controls on metal mobility in the subsurface. It was determined that the microbial abundance and community composition in soil overlying mineralization was significantly different than background locations, and therefore, can serve as a tool in the exploration for economic deposits. It was also determined that biogeochemical processes in the subsurface increase the mobility of metals, directly influencing the subsequent sequestration in the soil zone. Based on this research, it is clear that biogeochemical processes in the subsurface increase the development of the surficial soil anomalies used in the exploration for buried mineralization.