A Reconnaissance of the Joint-Systems in the Ouachita Mountains and Central Plains of Oklahoma

A brief study of the joints in part of central and southeastern Oklahoma leads to several interesting conclusions, chief of which are the following: (1) The Ouachita Mountains, as manifested at the present surface, were probably formed after middle (Oklahoma) Permian time. This increases their well-known resemblance to the Appalachian Mountains. (2) A prominent joint-system in the Central Plains of Oklahoma radiates fanlike from the Ouachita Mountain arc. Its origin was doubtless due to the mountain orogeny. (3) The individual, short faults of the so-called "en échelon fault belts" of the Central Plains correlate very closely in strike with the outstanding joint-system. This seems to tie the genesis of these faults to the Ouachita Mountain diastro-phism more closely than hitherto recognized. (4) A tentative general conclusion is stated as to the probable sequence of jointing and folding where the sedimentary beds have been mildly folded.