title: Sediment Core Extrusion Method at Millimeter Resolution Using a Calibrated, Threaded-rod.
abstract: Aquatic sediment core subsampling is commonly performed at cm or half-cm resolution. Depending on the sedimentation rate and depositional environment, this resolution provides records at the annual to decadal scale, at best. An extrusion method, using a calibrated, threaded-rod is presented here, which allows for millimeter-scale subsampling of aquatic sediment cores of varying diameters. Millimeter scale subsampling allows for sub-annual to monthly analysis of the sedimentary record, an order of magnitude higher than typical sampling schemes. The extruder consists of a 2 m aluminum frame and base, two core tube clamps, a threaded-rod, and a 1 m piston. The sediment core is placed above the piston and clamped to the frame. An acrylic sampling collar is affixed to the upper 5 cm of the core tube and provides a platform from which to extract sub-samples. The piston is rotated around the threaded-rod at calibrated intervals and gently pushes the sediment out the top of the core tube. The sediment is then isolated into the sampling collar and placed into an appropriate sampling vessel (e.g., jar or bag). This method also preserves the unconsolidated samples (i.e., high pore water content) at the surface, providing a consistent sampling volume. This mm scale extrusion method was applied to cores collected in the northern Gulf of Mexico following the Deepwater Horizon submarine oil release. Evidence suggests that it is necessary to sample at the mm scale to fully characterize events that occur on the monthly time-scale for continental slope sediments.
authors: College of Marine Science, University of South Florida; pschwing@mail.usf.edu.
authors: Patrick T
authors: PT
authors: Schwing
authors: College of Marine Science, University of South Florida.
authors: Isabel C
authors: IC
authors: Romero
authors: Marine Science and Chemistry, Eckerd College.
authors: Rebekka A
authors: RA
authors: Larson
authors: College of Marine Science, University of South Florida.
authors: Bryan J
authors: BJ
authors: O'Malley
authors: College of Marine Science, University of South Florida.
authors: Erika E
authors: EE
authors: Fridrik
authors: College of Marine Science, University of South Florida.
authors: Ethan A
authors: EA
authors: Goddard
authors: Marine Science and Chemistry, Eckerd College.
authors: Gregg R
authors: GR
authors: Brooks
authors: Marine Science and Chemistry, Eckerd College.
authors: David W
authors: DW
authors: Hastings
authors: College of Marine Science, University of South Florida.
authors: Brad E
authors: BE
authors: Rosenheim
authors: College of Marine Science, University of South Florida.
authors: David J
authors: DJ
authors: Hollander
authors: College of Marine Science, University of South Florida.
authors: Guy
authors: G
authors: Grant
authors: College of Marine Science, University of South Florida.
authors: Jim
authors: J
authors: Mulhollan
mesh_terms: D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods*; D019015:Geologic Sediments; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D014874:Water Pollutants, Chemical