2009 Portland GSA Annual Meeting (18-21 October 2009)

Paper No. 7
Presentation Time: 9:15 AM

CT-SCAN ANALYSIS OF EARLY ALBIAN VERTEBRATE REMAINS AND AMBER FROM A GUYOT IN THE MID-PACIFIC, ODP SITE 865


FIRTH, John V., International Ocean Discovery Program, Texas A&M University, 1000 Discovery Drive, College Station, TX 77845-9547, YANCEY, Thomas E., Dept. of Geology & Geophysics, Texas A&M University, College Station, TX 77843-3115, STIDHAM, Thomas A., Biology, Texas A&M University, Department of Biology, Texas A&M University, 3258 TAMU, College Station, TX 77843-3258 and ALVAREZ ZARIKIAN, Carlos A., International Ocean Discovery Program, Texas A&M University, 1000 Discovery Dr, College Station, TX 77845, yancey@geo.tamu.edu

A 30 cm thick mudstone sandwiched between oceanic island basalt sills near the base of ODP Hole 865A, Mid-Pacific Mountains, contains a lower Albian lagoonal crocodilian-bearing vertebrate fossil lagerstätte (Firth et al., 2006). Initial study of this deposit was restricted to examination of surfaces of core pieces, and disaggregation of selected pieces from the working half of the core, which yielded several crocodilian teeth, a variety of fish teeth, abundant fish scales, and a few unidentified vertebrate bones. Recent high resolution and ultra-high resolution CT-scanning of this core interval has enhanced our census of the fossil assemblage by allowing us to non-destructively view abundant hidden vertebrate remains inside both the archive half and working half of the core, as well as other fossils inside small pieces of amber extracted from the core. The CT-scanning also allowed us to more fully examine the sedimentary features through this interval to better understand its depositional history. Comparison of 3-dimensional imaged fossils with additional extracted fossils from the working half of the core have allowed us to improve our identification of some of these specimens. We will show a compendium of 3-dimensional images to illustrate the variety and extent of this unique oceanic island/lagoonal biota.