APPLICATION OF RAMAN SPECTROSCOPY ON BURGESS SHALE TYPE PRESERVATION

Cambrian strata host more examples of soft-bodied fossil preservation than any other time in the Phanerozoic. Although these sites are found globally, the cause(s) of this preservation, often dubbed Burgess Shale-Type (BST), is unknown. In order to better understand the chemical and molecular composition of BST fossils, with the ultimate goal of unraveling the underlying preservational mechanisms, we applied Raman Spectroscopy to a variety of BST fossils. As multiple excitation lines were used, this non-destructive technique allows us to determine the mineral composition of both a fossil and its surrounding matrix, as well as determining the maximum temperature of thermal alteration experienced by the carbonaceous material within the fossil. Samples studied include fossils from the Chengjiang biota and the Kali Formation in China, the Early and Middle Cambrian Pioche Shale from Nevada, and Middle Cambrian Spence Shale Member of the Langston Formation in Utah. Preliminary data are suggestive of the fact that these soft-bodied fossils have been preserved through a variety of mechanisms.