The area in and around Hot Springs National Park offers many tine exposures of Ordovician through Mississippian reeks along with some recent formations particular to the thermal springs (Stone and Bush, 1982). These strata are often steeply inclined to overturned, with many tight folds and numerous thrust faults formed by the late Paleozoic orogeny that uplifted the Ouachita Mountains. These rocks often contain quartz veins, small Cretaceous-age igneous dikes, and both hot and cold springs. The units to be examined in this area include the Middle Ordovician age Bigfork Chert, the Upper Ordovician age Polk Creek Shale, the Silurian-age Missouri Mountain Shale, the Devonian-Mississippian Arkansas Novaculite, and the Missis-sippian-age Stanley Shale (including the Hot Springs Sandstone Member). Roads that lead up to the crest of Hot Springs Moun-tain and West Mountain have several lookouts that provide viewsof the surrounding countryside. A high tower on Hot Springs Mountain is an excellent place to view the wide Mazarn Basin (a synclinorium underlain by Mississippian age Stanley Shale), the distant Trap Mountains (formed mostly by the Devonian-Mississippian Arkansas Novaculite), the Zigzag Mountains (Ar-kansas Novaculite and other formations), and the “core’ area of the Ouachita Mountains (an anticlinorium with extensive expo-sures of Ordovician sediments).
Figures & Tables
One of six volumes generated by each GSA section for the Decade of North American Geology (DNAG) project, this Centennial Field Guide contains descriptions of 100 sites or site clusters representing outstanding geologic locations in Arkansas, Kansas, Oklahoma, and Texas.