AMERICAN GEOLOGY SURVEY UNDER KING. 611 



accumulated detritus, interrupted by one and followed by another 

 period of deep-sea limestone formation. 



At the close of this great conformable period of Paleozoic deposi- 

 tion there were widespread mechanical disturbances. All the thickest 

 part of the sediments, from the western shore line eastward to and 

 including what is now the Wasatch, were raised above the ocean level 

 to become a land area. East of the Wasatch the ocean bottom, with 

 its Upper Carboniferous sediments, remained practically undisturbed. 



Contemporaneous with or immediately succeeding this uplift, the 

 old land mass to the westward went down. What was sea bottom had 

 become land, and what was land became sea bottom. But the new 

 land area extending from the Wasatch westward to the Havallah 

 range (long. 117° 30'), under the combined action of heat, cold, and 

 mechanical action of the atmosphere, began at once to yield the 

 materials which, in the form of sand and silt, were carried west and 

 cast to be laid down, in the first-named instance on a gradually sink- 

 ing Archean bottom, until a thickness of 20,000 feet was reached, and 

 in the last named, conformably upon a bottom of Upper Carboniferous 

 rocks, until some 3,S00 feet had accumulated. 



At the close of this period of sedimentation, which includes the 

 Triassic and Jurassic, the Western ocean with its twenty-odd thousand 

 feet of sediments underwent a sharp folding and uplifting, whereby 

 the shore line was pushed outward as far as the western base of the 

 present Sierra Nevadas. The force causing this uplifting acted tan- 

 gentially and was most severe in the extreme western portion, i. e., 

 the Sierras, where, in a belt of about 50 miles width, the Triassic and 

 Jurassic sediments were crumpled and crowded together and crushed 

 into a mass of almost undistinguishable folds. During all this power- 

 ful disturbance in the Western sea, the region east of the Wasatch 

 remained practically undisturbed, as before. 



King's views regarding the geographic distribution of land and 

 water during the subsequent period of geological history were largely 

 in harmony with those of Hayden. During the Cretaceous times he 

 believed a Mediterranean ocean to have stretched from the eastern 

 base of the Wasatch into Kansas. Over the bottom of that body of 

 water an almost continuous conformable sheet of Cretaceous sedi- 

 ments was laid down, the greatest thickness of which was against the 

 western shore of the ocean — that is, along- the base of the Wasatch, 

 where were found, conformably over the Jurassic shales, about 12,000 

 feet of Cretaceous beds. 



With the close of the Cretaceous period of sedimentation the entire 

 area from and including the Wasatch, eastward as far as the Missis- 

 sippi Valley was uplifted, and in its western portion faulted or thrown 

 into sharp or gently undulating folds. The immediate effect of this 

 uplifting was, first, the development of the broad level region now 



