44 SEDIMENTARY GROUPS OF THE PLATEAU PROVINCE. 



REMARKS ON THE GENERAL SECTION. 



The thicknesses which I have given in the table are considered to be 

 nearly an average. Many of the groups are much thicker in some places, 

 and thinner in others. If the maximum thickness of each had been given, 

 the sum would have been more than 70,000 feet; while if the minimum 

 had been given the sum would have been reduced nearly to 50,000 feet. 

 The Mesozoic and Paleozoic sediments in all latitudes where they have 

 been studied, are found to attenuate as you pass from the western to the 

 eastern border of the province. 



In characterizing the rocks I have attempted to give only those 

 features which are general throughout the province so far as it has been 

 studied ; but there are many local peculiarities which we have observed 

 and which will appear in the detailed reports. 



LOCALITIES WHERE THE SEVERAL GROUPS CAN BE STUDIED. 



I now append a few localities where these several groups can be seen 

 under favorable circumstances. They might be multiplied greatly, but 

 perhaps no good purpose would thus be served. 



BISHOP MOUNTAIN CONGLOMEEATE. 



The Bishop Mountain Conglomerate can be seen on the summit of 

 Bishop Mountain, where it lies unconformably on the eroded beds of the 

 Bitter Creek Group. A fine exposure can also be seen on the summit of 

 the Quien Hornet Mountain. 



BROWN'S PARK GROUP. 



This group is well represented at Brown's Park, in Northeastern Utah 

 and Northwestern Colorado. 



A good section can be obtained in the high bluffs on the west side of 

 the Snake River by commencing about five miles above its confluence with 

 the Yampa where these beds are seen to rest unconformably against Car- 

 boniferous strata at the foot of the mountain. In going north two minor 

 flexures are passed where the upper members of the group are exposed ; 

 and, on reaching a third and greater upheaval, the group is exposed from 

 summit to base, and is seen to rest unconformably upon Bridger beds. 



