STRAND MARKINGS IN THE PENNSYLVANIAN SAND- 
STONES OF OSAGE COUNTY, OKLAHOMA? 
SIDNEY POWERS 
Tulsa, Okla. 
INTRODUCTION 
CONDITIONS OF SEDIMENTATION 
DESCRIPTION OF MARKINGS 
HYPOTHESES OF ORIGIN 
CONCLUSIONS 
INTRODUCTION 
While mapping geologic structure in Osage County, Oklahoma, 
the attention of the writer was called to certain grooves on bedding 
planes which resemble glacial striae and slickensides, although 
clearly of strand origin. They are but one of the many kinds of 
markings formed along shores or in shallow water. From parallel 
groovings over broad areas there are all gradations to irregular 
markings which are clearly casts of impressions in the mud. The 
markings appear both on upper and lower surfaces of sandstone 
beds, but they are more common on lower surfaces. 
Similar markings in sandy beds of the Portage group of the 
Upper Devonian of Naples, New York, have been described in 
detail recently by Dr. John M. Clarke? and many years ago by 
Professor James Hall. They have also been found in the Strawn 
formation of Pennsylvanian (Pottsville) age, both south of Strawn, 
Texas, and east of San Saba, in San Saba County, Texas. Grooves 
of similar nature are known in the Beekmantown of Valcour 
Island, Lake Champlain.s No doubt they are much more common 
than these few localities indicate. 
* Published by permission of the director, United States Geological Survey. 
2“Strand and Undertow Markings of Upper Devonian Time as Indications of 
the Prevailing Climate,” New York State Mus., Bull. 196 (1918), pp. 199-210. 
3 Geology of the Fourth District of New York (1843), pp. 234-37. 
4 The latter locality is known to Dr. J. A. Udden, of Austin, Texas. 
5 Personal communication from Dr. Rudolf Ruedemann, of Albany, New York. 
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