Paleoenvironmental analysis of the Lenoir Limestone of southern Knox County, Tennessee.

Analysis of approximately 150 thin-sections of Middle Ordovician Lenoir Limestone in southern Knox County, Tennessee has shown this 600-700 feet of sediment was deposited in a lagoonal environment that occurred between reefs, represented by the KnoxDolomite. The Mosheim Member of the Lenoir Linestone represents intertidal deposition on an extensive intertidal flat. The upper member of the Lenoir represents subtidal deposition in a lagoon. This upper member is composed of four sub-environments reflecting differences in water depths and floral and faunal composition. Environmental analysis is based largely on the presence or absence of algae, particularly Girvanella sp., the condition of preservation of algae, and invertebrate faunal composition. The study has shown that zones most abundant in Girvanella sp. and in some cases other algae (Nuia siberica, Solenopora sp., Hedstroemia sp.) closely approximate previously established zones containing abundant corals (Lichenaridae), bryozoans, and sponges (Allosaccus prolixus).