Summary Thermocouple arrays were deployed on two deep‐sea hydrothermal vents at Guaymas Basin (27°0.5′N, 111°24.5′W) in order to measure in situ temperatures at which microorganisms colonize the associated mineral deposits. Intact sections of three structures that formed around the arrays were collected after 4 and 72 day deployments (named BM4, BM72 and TS72). Archaeal diversity associated with discreet subsamples collected a...