Awardee: Benjamin Kimball Harrison (University of Minnesota)
Current Placement: Environmental Scientist, Port Gamble S'Klallam Tribe
Degree: Ph.D. Geochemistry, California Institute of Technology (2011)
Advisor: Jake V. Bailey (University of Minnesota)
Amount: $111,228.00
Award Dates: April 1, 2012 — April 30, 2014


Previous investigation of the microbial diversity of unconsolidated marine sediments has not yet constrained the importance of cell transport associated with physical processes of sedimentation and fluid advection. To that end, our ongoing research seeks to describe the permanence and overprinting of molecular signatures of microbial communities across discrete horizons associated with rapid sedimentation (e.g. turbidite emplacement), changes in bottom-water geochemistry, and depositional unconformities. Over the course of this postdoctoral fellowship I addressed these problems through the collection and study of sediment cores collected from 3 lakes in the Minneapolis-St. Paul Metropolitan area and an intact turbidite profile recovered from La Jolla Canyon on the California Borderland. These core samples provided a key opportunity to study microbial relationships to sedimentology at high resolution. Preliminary work suggests microbial community signatures retain evidence of cell displacement resulting from sediment disturbance, and distinct patterns in diversity are not overprinted on decadal timescales.