552 Notices respecting New Boohs. 



Below the " Pink Cliffs " of the Eocene beds, Cretaceous sand- 

 stones and shales (nearly 5000 feet thick) form rolling ridges, 

 yellowish in tint, with long hill-sides and rocky pine-clad promon- 

 tories, over a platform varying from 4 to 10 miles in width. More 

 eastward they widen out with numerous ledges, tier above tier, 

 sharply defined, symmetrically sculptured, and peculiarly coloured 

 with light yellow and brown, set off with the dark grey belts of 

 shale. 



The Jurassic formation, consisting of red fossiliferous shales 

 (from 300 to 500 feet thick) and an underlying white sandstone, 

 nearly 1000 feet thick, forms a platform stretching along beneath 

 the Cretaceous escarpment, with a varying width of about 10 

 miles and less. The great unfossiliferous white sandstone is very 

 peculiar, — massive, homogeneous, cross-bedded throughout. Some- 

 times it presents simple straight cliffs, sometimes the white wall 

 is cut into bastions and bays, buttes, temples, and dome-shaped 

 masses, with outlying forts nearly 1000 feet high. At one locality 

 (the Colob) grotesque anomalous rock-forms, curved, hummocky, 

 and wobbly, have been weathered out of the sandstone*. 



Strata belonging to the Trias form a still lower plateau or plat- 

 form, at some places more than 15 miles broad, elsewhere very 

 narrow, within the scarped terraces already described as curving 

 irregularly round, on the north and east within the district which 

 is drained into the Marble and Grand Canons. " The splendour of 

 the terraces culminates in the Trias." These cliffs, in some places 

 2000 feet high, are composed of relatively thin-bedded sandstones, 

 often gypseous, with shaley beds in the lower portion. The 

 sharply defined and fretted edges of the horizontal strata, form- 

 ing delicately moulded, vertical, cliff-like ledges and plinths, and 

 their successive " water-tables " or talus-banks, with graceful 

 feebly concave slopes, constitute a complex profile, made up of 

 simple elements, and keeping a definite type throughout, though 

 locally modified. Wonderfully red with varied tints, banded at 

 intervals with white, and traversed by the hollow lines of dissolved 

 gypsum, they are carved vertically, as by a bold architectural 

 sculptor of immeasurable power, into pinnacles, gables, buttresses, 

 towers, and dome-like forms, often in stages and tiers to vast 

 heights, all " of great beauty and grandeur, with strongly emphasized 

 vertical lines and decorations, suggestive of cathedral architecture 

 on a colossal scale." These are the leading features of the incom- 

 parable " Vermilion Cliffs," especially in their greatest perfection 

 among " the temples and towers of the Virgen," where that valley 

 comes down in more than picturesque gorges and canons from the 

 Eocene heights through the successive plateaus already mentioned. 



* The filagree plexus of curved lines in the face of the cliffs of this 

 bedless mass suggests to us an seolian origin ; and the Colob looks as if it 

 owed its bizarre forms to concretionary conditions of this curious Jurassic 

 sandstone. It is doubtful if it belongs to the Jurassic or to the Triassic 

 series j it might be the blown-sands of the Triassic sea. 



