1. Neoproterozoic Sulfur Isotopes, Snowball Earth Events and the Evolution of Microbial Sulfur Species Open Access Author: Hurtgen, Matthew T. Title: Neoproterozoic Sulfur Isotopes, Snowball Earth Events and the Evolution of Microbial Sulfur Species Graduate Program: Geosciences Keywords: sulfur isotopesNeoproterozoicsnowball Earthsulfate concentrationsPrecambrianNamibia File: Download thesis.pdf Committee Members: Michael Allan Arthur, Committee Chair/Co-ChairLee Kump, Committee MemberHiroshi Ohmoto, Committee MemberCharles Raymond Fisher Jr., Committee Member