Ouachita Mountains, Arkansas and Oklahoma
Image: A slurry bed from the Jackfork Formation, Ouachita Basin.
The Ouachita Trough was a predominantly fine-grained, quartz-rich, continent-sourced depositional basin along the southern margin of the North American Craton that evolved from a sediment-starved passive continental margin from the Cambrian to the Mississippian. Subsequent closing of the basin, initiated in the Mississippian, formed an elongate, narrow foredeep and orogenic highlands to the south (Mississippian-Pennsylvanian).
One chapter in a PhD thesis by Tom Hickson (1999) focused on turbidity current and slurry flows deposits in the Jackfork Group in the classic DeGray Spillway section. In addition, Tracey Chester (1994) conducted a statistical analysis of bedding trends in the Jackfork Formation at DeGray Spillway.
Currently, Larisa Masalimova is starting a study of slurry beds in the Jackfork Group. Slurry flows, sediment flows transitional between turbidity currents and debris flows, are being increasingly recognized as major components of deep-water sequences and have a strong influence on the properties and distribution of sand beds. Larisa will be studying both the sedimentation mechanics of the depositing flow and the environmental distribution of slurry-flow deposits within the overall Jackfork depositional system.