Johnson, Beverly J.2015-09-112015-09-111990http://udspace.udel.edu/handle/19716/17020Amino acid analyses were performed on four planktonic species of foraminifera and a mixed foraminiferal species assemblage through the Quaternary section of Ocean Drilling Program Site 625B in the northeast Gulf of Mexico. The extent of isoleucine epimerization in the individual species increased with time as the overall rate of epimerization decreased with time. Extents of epimerization among the species in increasing order are Globigerinoides ruber, Orbulina universa, Neogloboquadrina dutertrei and the Globorotalia tumida-menardii complex. The mixed foraminiferal species assemblage was found to epimerize at a rate intermediate to the limits delineated by Globigerinoides ruber and the Globorotalia tumida-menardii complex.ForaminiferaGulf of Mexico, United StatesQuaternary sectionThesis