Do microbes control the formation of giant copper deposits?

One of the major issues when studying ore deposits formed in surficial or near-surface environments is the relationship between ore-forming processes and bacteria. At a first glance, these environments appear to be a preferred place for the growth of microbial ecosystems because they potentially have large amounts of nutrients. However, studies have been restricted because of the low likelihood of microbe fossilization and because biomarkers are not always definitive.