ABSTRACT

Petrographic and sedimentological analysis of the Middle to Late Devonian Sylamore sandstone member of the Chattanooga Formation allows it to be classified as Fine Sandstone: Siliceous submature or supermature usually phosphate bearing quartzarenite and subchertarenite. The Sylamore contains sedimentary rock fragments, inherited quartz overgrowths, and reworked Ordovician conodonts indicating a sedimentary provenance. Mineralogical and textural comparison with the Ordovician Burgen sandstone suggest that the latter was a source of sediments for the Sylamore. Two species of conodonts indigenous to the Burgen that are found as recycled constituents in the Sylamore support this conclusion. Probability scale plots of grain size distribution and the presence of abundant phosphate indicate a near shore, shallow marine environment of deposition. Unweathered detrital feldspar, length slow chalcedony, and gypsum suggest an arid climate. The composition of the Sylamore has been only slightly effected by diagensis. Secondary porosity from grain dissolution is locally present.