Olistostromal deposits are extensive in the Silurian(?) to Lower Devonian Lay Dam Formation in the Talladega slate belt of central Alabama. These rocks form part of a thick (2 to 3 km) clastic sequence deposited unconformably above the upper Precambrian(?) to Lower Ordovician Appalachian miogeocline displaying a rifted to passive margin, clastic and carbonate bank facies. The Talladega belt is a far-traveled Alleghanian thrust sheet metamorphosed to lower greenschist facies during the Acadian orogeny and thrust above the foreland fold-and-thrust belt. The olistostromes are commonly several hundred meters thick and extend laterally for tens of kilometers. They are unsorted, unbedded,...