JUEASSIC WHITE SAimSTONE— CEOSS-BEDDING. 153 



simple in the extreme, and majestic by reason of their simplicity. The 

 color of the rock is almost always gray, verging towards white. Occasion- 

 ally it is a very pale cream color, and again pale red. The red becomes 

 more common as we recede from the old shore line towards the east. 

 But of all the features of this rock the most striking is the cross-bedding. 

 It is hard to find a single rock-face which is not lined off with rich tracery 

 produced by tlie action of weathering upon the cross-lamination. The 

 massive cliff-fronts are etched from summit to base with a filagree as intri- 

 cate and delicate as frost-work. The same phenomenon is seen in the Ver- 

 milion Cliff sandstones below, often so rich and complex that it excites 

 constant admiration. Dr. Newberry speaks of it with enthusiasm as pre- 

 sented in the Triassic sandstones of New Mexico. But it is far less won- 

 derful than the cross-bedding which the Jurassic presents at every exposure. 

 In the Colob Terrace, south of the Markdgunt, the rock weathers into many 

 cones and pyramids, and the details produced by the action of the weather 

 upon the cross-bedding are grotesque and often ludicrous. A journey down 

 the Upper Kanab Canon is enlivened by ever-recurring displays of this 

 phenomenon, presented with a profuseness and variety which extort excla- 

 mations of delight from the beholder. The Jurassic sandstone was de- 

 posited over an area which cannot fall much short of 35,000 square miles, 

 and the average thickness exceeds 1,000 feet. The imagination is utterly 

 baffled in the endeavor to conceive how a mass so vast and at the same time 

 80 homogeneous and intricately cross-bedded throughout its entire extent 

 could have been accumulated. 



Overlying the white sandstone is a series of beds which may be called 

 shales with some reservation, and here we find for the first time an abun- 

 dance of distinctive fossils. They are clearly of Jurassic genera and species, 

 and enable us to correlate the horizon with confidence. They belong to a 

 well-marked formation, which is represented not only throughout the greater 

 part of the Plateau Province, but also in Colorado, Wyoming, and Northern 

 New Mexico. From many large areas, indeed, it has been denuded, but 

 throughout Utah it is never wanting from those exposures where its pres- 

 ence could be looked for. 



That constancy of lithological character which is so conspicuous in 



