Document Type
Thesis
Abstract
Sclerochronologic and isotopic analyses were performed on fossil oysters and clams from the Piankatank River, VA, with the goal of reconstructing late Pleistocene seasonality and unraveling the nature of internal growth bands in Crassostrea virginica. Mass spectrometry of powdered shell carbonate allowed the generation of 5'80 profiles, which were used to calculate temperature and evaluate the nature of internal growth banding. The data indicate a temperature range similar to, although perhaps more limited than that of today. There is a clear relationship between temperature and the chalky and translucent growth increments of C. virginica, but it is not strong enough to replace isotopic analyses in the determination of biological age in that species. Growth increments appear to be annual in nature for the first 5-8 years of growth. After that, the oyster either changes its banding regime or ceases depositing shell carbonate in isotopic equilibrium with the water. These results contribute to our understanding of Pleistocene climate and oyster growth by placing additional constraints on both.
Date Awarded
2014
Department
Geology
Recommended Citation
Dale, Eric, "Reconstructing Pleistocene seasonality via Crassostrea virginica and Mercenaria mercenaria sclerochronology, Holland Point, VA" (2014). Geology Senior Theses. William & Mary. Paper 308.
https://scholarworks.wm.edu/geologyseniors/308
