Clark, Sandra H. B. <br/><br/>
Barite nodules in Devonian shale and mudstone of western Virginia / 
by Sandra H.B. Clark and Elwin L. Mosier 
 - Washington, D.C. :  United States Geological Survey,  1989 
 - iv, 30 p. :  ill. ;  28 cm. 
 - U.S. Geological Survey bulletin ;  no.1880 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Barite--Virginia<br/>Barite--Appalachian Region<br/>Geology, Stratigraphic--Devonian
<br/><br/><label>Dewey Class. No.: </label>553.662