INVESTIGATIONS OF ANCIENT CAMBRIAN ROCKS IN 

 THE UNITED STATES 



By CHARLES E. RESSER 



Curator, Division of Invertebrate Paleontology 



U. S. National Museum 



With the objective of studying Cambrian strata across the country, 

 we set out from Washington late in June in a light truck equipped 

 with beds and stocked with food, so that we might sleep and eat 

 wherever it suited the exigencies of the work. Charles H. Frey, 3rd, 

 a student at Franklin and Marshall College, served as field assistant. 



Our first problem was to relocate two faunas on Copper Ridge, 

 northwest of Knoxville, Tenn., for several questions had arisen con- 

 cerning their geographic and stratigraphic position. During our brief 

 investigations we were able to find excellent material representing 

 one of these faunas. 



For many years I had hoped to become acquainted with the im- 

 portant Cambrian section in the Ozark Mountains. Accordingly, we 

 chose a route through Missouri and spent the better part of a week 

 in looking over the outcrops along the streams and roadsides in the 

 vicinity of Farmington and Van Buren. Here life was made miserable 

 by the superabundance of chiggers, something evidently out of the 

 ordinary because local newspapers were printing many stories of like 

 experiences. 



Our next objective was to examine the Cambrian rocks of Colorado. 

 They are mainly quartzitic and therefore have few fossils, which 

 makes their study difficult. A sequence of Cambrian beds occurs in 

 the Front Range near Manitou and in some of the natural parks char- 

 acteristic of the eastern Colorado Rockies. This thin series of beds 

 was studied near Manitou and in Manitou Park, 70 miles to the north. 

 Another sequence, found in the Mosquito, Sawatch, and other ranges, 

 was viewed briefly west of Xennessee Pass and in Glenwood Springs 

 Canyon but we were unable to attempt the higher altitudes around 

 Aspen because our truck did not have sufficient power to climb 

 the very steep grades. 



The next stop was at the Grand Canyon where the Park naturalist, 

 Edwin McKee, by persistent effort has obtained many good fossils 

 and much new information. Arrangements were made for joint pub- 

 lication of the results during the coming year. Outcrops were ex- 

 amined in Meriwitica and Peach Springs Canyons, about 150 miles 



