Document Type
Thesis
Abstract
Carmel Church Quarry (CCQ), a mylonite sand and gravel quarry in Caroline County, Virginia, exposes six Tertiary formations within a 10 m thick section, which includes the Calvert Formation. Published research on this site is limited and much of it involves systematic descriptions of organisms that have been found. The research presented here will contribute to the understanding of cetacean taphonomy and the local depositional environment, and will facilitate the comparison of more western, near-shore Calvert deposits with more common eastern exposures. In order to evaluate the taphonomy of the cetacean material from the Calvert Formation at CCQ, I examined 288 prepared vertebrae housed at the Virginia Museum of Natural History. This study focuses specifically on determining whether preferential preservation is occurring among the four sections of the cetacean vertebral column ( cervical, thoracic, lumbar, and caudal) and determining whether the environment is influencing the preservation of the vertebrae. The vertebrae were measured for size (volume of centrum) and several anatomical and preservational observations were recorded: part of the vertebral column to which each belongs; found isolated, associated, or articulated with other vertebrae; preservation state on a scale of 1 (pristine) to 4 (heavily abraded); and presence or absence of epiphyses. We found that there are no biases in the preservation likelihood by vertebral region, with the exception of the atlases, which are over-represented relative to axes within the sample collection. Adult vertebrae tend to be better preserved than juvenile and calf vertebrae. Articulated and associated vertebrae tend to be better preserved and larger than isolated vertebrae. Articulated vertebrae and those in more pristine conditions came from adult (both epiphyses present) cetaceans. The sedimentology suggests a low-energy environment with the presence of angular sand grains and well-preserved and articulated vertebrae; however, the abundance of large, well-rounded cobbles suggests high-energy. Overall, preservation may be related to the size of individuals more than to the energy of the environment.
Date Awarded
2011
Department
Geology
Advisor 1
Rowan Lockwood
Advisor 2
Alton Dooley
Recommended Citation
Byrd, Christina J., "Taphonomy of Miocene Cetacean Vertebrae from Carmel Church Quarry, Virginia" (2011). Geology Senior Theses. William & Mary. Paper 248.
https://scholarworks.wm.edu/geologyseniors/248
