The primary objective of this dissertation is to characterize freshwater microbial palustrine deposits, and assess how their textures and geochemical characteristics change over various stages of early burial and diagenesis in order to assess their recognition and preservation in the geologic record. A detailed study of sediments, microbial communities, and chemical environments was carried out for a sequence of cored Holocene deposits, from the modern surficial freshwater environment and seaward to those similar sediments buried during the Holocene transgression in the Florida Everglades (mainly terrestrial) and Florida Bay (full marine). In addition, the early diagenesis of microbial lime mud is also included as part of this dissertation to compare and contrast the diversity of microbial sediments and their diagenesis