Dutton— Tertiary History of Grand Canon District. 87 



widely-extended estuary and terrestrial conditions. The Cre- 

 taceous seas probably stretched across from the Gulf of Mexico 

 to the Pacific, with interruptions only of narrow emerged 

 areas — that of the Great Basin being one of these, and another 

 in Arizona. Between these two areas, or along the parallel- of 

 34° and 37°, " we can now travel from the Mississippi to the 

 Pacific without being at any time more than fifty miles dis- 

 tant from some known mass of Cretaceous beds;" and "every 

 indication we now have raises a presumption in favor of a 

 complete connection. 7 ' The distance is nearly 2,000 miles. 



"At the close of the Cretaceous, important vertical move- 

 ments were inaugurated, and around the borders of the Pla- 

 teau province some important flexures were generated." This 

 epoch, the close of the "Lignitic" or "Laramie" formation, 

 was that, it is supposed, of the making of the Wasatch Moun- 

 tains. A great nn-a. ('mm the Aquarius plateau to the Colo- 

 rado, must have been denuded at this time of the Cretaceous, 

 so that the Tertiary over it was laid down on the Jurassic 

 beds; and similar facts occur at other points indicating rhar 

 "the Cretaceous closed amid important disturbances. Still the 

 deposition of strata was not ended." The depositions of Eocene 

 beds went forward in fresh waters until 1200 to 5,000 feet of 

 strata were added to the ^ent - tin ' wN -howiim tint a single 

 lake extended from the Uinta Mountains southward over the 

 Plateau region ; that the elevation was sufficient, and suffi- 

 ciently persistent to make great lake-basins: and evincing, 

 also, since the beds are successively of shallow water origin, 

 that, as before, a subsidence was going on over the Eocene 

 lake region to as great a depth as the thickness of the beds. 

 The earlier subsidence had been greatest in the line of the 

 Wasatch Mountains: the later was most so farther to the north- 

 eastward, in the region of the Uinta Mountains, where Eocene 

 beds have a thickness of 5,000 feet and the great Eocene lake 

 made its final disappearance, only the lower Eocene occurring 

 over the Plateau District. 



The Miocene depositions followed, but it is difficult to find 

 "in this district anv epoch separating the later Eocene from 

 the Miocene; and o'f the Pliocene nothing is known from any 

 beds or fossils. Both eras were no doubt eras of gradual 

 emergence; at the close of the Miocene an uplift took place of 

 prohabiv 2,000 to 3,000 feet, and at or near the close of the 

 Pliocene a greater upheaval of 3,000 to 4,000 feet," 



The making of the great nortli-aml-south faults of the pla- 

 teau region — first described by Powell — some of which extend 

 northward ovei the regi. n of the " High Plat, an-*' far toward 

 the Wasatch Mo mtains. \ egan. iccording to the author, at the 

 close of the Miocene, and went on for some of them during the 



