[Truncated abstract] This thesis describes the 'living' microbialites in Lake Clifton, a marine-derived coastal lake in south-western Australia. The local environment (both geological and hydrological), the benthic microbial community and associated metazoan fauna were investigated to elucidate the process of microbialite formation. The character of microbialitic internal fabrics and external forms were studied to determine the effect of biological and environmental controls on microbialite growth. Comparisons of many aspects of the Lake Clifton microbialites were made with contemporary and fossil microbialites to assist in determining factors responsible for microbialite growth both today and in the past. Microbialites are organosedimentary deposits that have accreted as a result of a benthic microbial community (BMC) trapping and binding detrital sediment and/or forming the locus of mineral precipitation. Stromatolites and thrombolites are two of several forms of microbialites. Although they may have similar external forms, it is their internal structure that sets them apart. Stromatolites are characterised by an internal structure of discrete laminations, whereas thrombolites are characterised by an internally clotted texture and lack fine laminations. The decline of stromatolites at the end of the Proterozoic and the rise of thrombolites during the Cambrian have been related to the evolution of burrowing and grazing metazoans, and it has been suggested that the thrombolites were the result of metazoan activity disrupting the original stromatolitic laminae.
|Qualification||Doctor of Philosophy|
|Publication status||Unpublished - 1993|