Upper Ordivician Sequatchie Fo essays

Upper Ordivician Sequatchie Fo essays Rocks belonging to the Ordovician System are exposed along Interstate 75 between Cleveland and Chattanooga in a road cut in White Oak Mtn or sometimes called Green Gap. These rocks show the upper portion of the Middle Ordovician Catheys Formation and all of the Upper Ordovician Sequatchie Formation including the Fernvale Member. The road cut exposes a section of rock that was measured at two hundred and seventy-five feet. This stratigraphic section was examined in detail to determine the paleodepositional environment in which these sections of rock were deposited. There are a total of five units that have been identified and the lithography studied in detail. These five units will be split up and described separately to clarify the content of each unit more easily. Unit one represents the Catheys Formation. This unit grades upward and has a scoured bottom. This unit consists of mostly calcirudite and shale layers with occasional siltstone overlying the calcirudite. There are nine cycles present in this unit. There are skeletal debris as well as burrows present in these layers. These rocks are carbonate-rich as well. The siltstone suggests a low energy environment of deposition, but the burrows tell of slightly more energetic conditions. Unit two represents the Sequatchie Formation. There are thin beds of calcareous siltstone that range in thickness from 1 to 1. There are fossil remnants here as well. The siltstone is rippled and cross-beds are present. Some red shales are present, which may hint to us a beach was present at that particular time of deposition. This will account for the green as well as the red rocks and also the thin-bedded ripples present. Unit three represents the Sequatchie Formation as well. The rocks present in this unit are mostly of green color, which leads us to believe they were oxidized. This unit shows evidence of a tidal flat or tidal complex ...