Notices respecting New Books. 553 



Here u the slopes, the winding ledges, the bosses of projecting rock, the 

 naked scanty soil, display colours which are truly amazing. Chocolate, 

 maroon, purple, lavender, magenta, with broad bands of toned white, are 

 laid in horizontal belts, strongly contrasting with each other ; and the 

 ever-varying slope of the surface cuts across them capriciously, so that 



the sharply-defined belts wind about like the contours of a map Across 



the canon, and rather more than a mile and a half beyond it stands the 

 central and commanding object of the picture, the ' western temple/ 

 rising 4000 feet above the river. Its glorious summit was the object we 

 had seen an hour before, and now the matchless beauty and majesty of its 

 vast mass is all before us. Yet it is only the central object of a mighty 

 throng of structures, wrought up to the same exalted style, and filling up 

 the entire panorama." (Pp. 57, 58.) 



The lowest (first) stratum of the Trias sic formation is the Shina- 

 rump conglomerate ; and this, unlike the basal beds of the other 

 formations, which end with their cliffs, protrudes from below, 

 extending far over the next lower (Permian) platform towards its 

 edge. This brownish, coarse, and conglomeratic sandstone is 

 usually from 40 to 75 feet, sometimes even 100 feet thick ; but 

 occasionally it is absent. It lies horizontally on an eroded surface 

 of the Permian shales, and with the underlying strata was included 

 by Powell in his " Shinarump Group," in some lower beds of which 

 Permian fossils have been found. As a strong feature in the region 

 and on account of its apparent unconformity, Walcott and Dutton 

 keep it now with the Trias *. 



The Permian consists of thin beds of sandy shales and impure 

 limestone, traceable, like those of the Trias, for miles and miles 

 along the richly coloured cliffs (about 1000 feet high) ending the 

 terrace. Horizontal streaks of chocolate, purple, and red-brown 

 are interstratified with violet, lavender, and white, in these grand 

 sections. Many outliers and " buttes " of Permian strata, and 

 isolated sheets of basalt, are scattered over the great plain or plat- 

 form of Carboniferous rocks, which stretches hence to the Grand 

 Canon (about 30 miles), and far away on the other side of the 

 great river. About 60 miles S. of the river the volcanic San- 

 Francisco Mountains are piled on the horizontal Carboniferous 

 strata, which continue as a level platform for 30 miles beyond, to 

 end abruptly in the Aubrey Cliffs overlooking the sierra country of 

 Central Arizona. The Grand Canon, where crossed by the N". and 

 S. line above indicated, namely between the Kanab and Kaibab 

 districts, consists of an inner and an outer (wider) chasm ; the 

 former about 1600 yards wide and 1000 yards deep ; the latter 

 from 4 to 5 miles wide, including its two lateral esplanades, and 

 more than 600 yards deep, making a total depth of at least 4800, 

 if not 5000, feet. Of this, some 400 feet are sunk into Devonian 

 and Silurian strata. These are highly inclined and contorted, richly 

 coloured, certainly 6000 and probably 10,000 feet thick. On the 



* Some analogy may be noticed between these great North- American 

 Permio-Triassic strata and the relations of the European Zechstein and 

 Bunter-Schief er, as argued by Sir K I. Murchison and disputed by others. 



