CROSS-BEDDING IN THE SALEM LIMESTONE OF CENTRAL INDIANA

In the middle Mississippian Salem Limestone of central Indiana 693 measurements showed that sediment transport during Salem deposition was to the southwest, as during deposition of most of the late Paleozoic sands of the Illinois Basin. Crossl bedding direction is variable, however, and noticeably bimodal. Oscillating tida-currents on a shallow marine shelf are believed to have caused pronounced bimodality in the Salem Limestone and in the associated Ste. Geneviève and Harrodsburg Limestones.