This project included the sequencing of sediment-basement interface samples from the eastern flank of the Juan de Fuca (JdF) Ridge and from the western flank of the Mid-Atlantic Ridge (North Pond, NP) in an effort to document the microbial community connection among deep sediments, oceanic crust, and circulating seawater. The sequenced samples were collected during IODP Exp. 327 (JdF; Fisher et al. 2011) and via gravity coring during cruise MSM11-1 (NP, Ziebis et al. 2012). Microsphere contamination controls were used during IODP Exp 327, and background control samples were included in this sequencing project.