Location of radiocarbon age dates sampled from vibracores collected by the U.S. Geological Survey within Apalachicola Bay, Florida, 2007 (APP-07_AgeDates, points)

Twenty-four vibracores were collected within Apalachicola Bay, Florida during May 2007. Vibracore sites were selected based on the identification of target areas. These target areas were chosen from the analysis of geophysical data collected during 2005 and 2006 in collaboration with the National Oceanic and Atmospheric Administration’s (NOAA) Coastal Services Center (CSC) and the Apalachicola Bay National Estuarine Research Reserve. The vibracores were collected using a Rossfelder electric percussive (P-3) vibracore system. The cores were collected in a 7.62 cm (3 in) diameter by 6.10 m (20 ft) long aluminum tube with a copper core catcher riveted to the bottom. The vibracoring rig was mounted, depolyed, and recovered on the port side of the R/V Gilbert. The ship was anchored from the bow and stern to maintain ship position as a hydraulic crane deployed and recovered the coring rig. Following recovery, the bottom of the core was capped with a plastic cap, water was drained from the top of the core barrel by drilling a hole in the aluminum tube immediately above the sediment/water interface, and the pipe was cut at the sediment/water interface. Each core was cut into one-meter sections (measuring down from the sediment/water interface) on the boat deck, the ends were capped, each section labeled, and stored on deck for transport. Core sections for all 24 vibracores were transported to the U.S. Geological Survey Florida Integrated Science Center (FISC) where the 1-meter core sections were split in half (lengthwise), described, and photographed in the FISC core laboratory. One half of each core section was preserved and archived in a clear plastic sleeve with the ends taped shut to minimize moisture loss. The other half, the working half, of the core was used for visual descriptions, photographs, and eventually sub-sampling. Visual core descriptions were recorded on field sheets that contained information regarding: cruise, core number, describer, general station location, lithologic units, sedimentary structures, biota, and a depiction of the stratigraphic column. The cores were photographed by aligning all sections of a vibracore abreast with depth indicators located between sections. After photographing, all core sections were wrapped in plastic sleeves with the ends taped shut to minimize moisture loss, and stored in labeled cardboard boxes in the FISC core repository.