LITERARY NOTICES. 



845 



the south-southwest, and having a breadth of 

 from twenty-five to eighty miles, and a total 

 area approaching nine thousand square 

 miles. They arc distinct, structurally and 

 topographically, from the Wahsatch range, 

 belong to another age, and are wholly dif- 

 ferent in their forms and geological rela- 

 tions. They are composed of early Tertiary 

 and late Cretaceous formations, nearly or 

 quite horizontal, and usually capped with 

 lava formations of exceedingly complex ar- 

 rangement. The region is for the most part 

 destitute of vegetation and soil, and dis- 

 sected by deep canons. Consequently, its 

 geology, as a whole, is plainly revealed, so 

 that every fault, every flexure, the relations 

 of successive unconformities, and all facts 

 of structure are seen at once ; but two 

 sources of obscurity exist, in that some of 

 the highest plateaus are covered with for- 

 ests and vegetation, and that the extrava- 

 sated rocks are aggregated in a more con- 

 fused manner than the sedimentary beds, 

 so that uncertainties and doubts still remain 

 after the utmost labor and care in tracing 

 them. The surface of the plateaus appears 

 to have formed the bottom of a lake in 

 Eocene times, and to have gradually risen 

 to its present height by a movement which 

 may still be going on. The drainage is by 

 the tributaries of the Colorado, whose chan- 

 nels were formed in the lake-bottom before 

 it was wholly dry, and have kept their course 

 and level where they are, " in spite of faults, 

 flexures, and swells, in spite of mountains 

 and plateaus," the streams turning neither to 

 the right nor to the left as these irregularities 

 were encountered, but persistently cutting 

 their way through the same old places, till the 

 present magnificent canons have been carved 

 out. Another salient feature of the region 

 is given by the extraordinai'ily extensive 

 faults, the results of displacements which 

 took place in relatively i-ecent times. Some 

 five or six of these great displacements are 

 from twenty to a hundred miles long, and 

 are of heights rising to a maximum of five 

 thousand feet. One of them, the Eastern 

 Kaibab fault, is the longest line of displace- 

 ment of which the author has any knowl- 

 edge ; it has a length which can not fall 

 much short of three hundred miles, and may 

 be found to exceed that after its termini have 

 been discovered, and a maximum height of 

 seven thousand feet. The displacements do 



not belong wholly to any one period, but arc 

 of distinct though not widely separated ages. 

 The erosions of the plateau do not' appear 

 to have been affected by the presence of ice 

 during the glacial epoch, but the evidence is 

 strongly in favor of the conclusion that the 

 climate in this district was not glacial. 

 " The ravines and valleys are conspicuous- 

 ly water-carved, and conspicuously not ice- 

 carved." Yet evidences of the former exist- 

 ence of small local glaciers are found on 

 the summits of the cliffs, not less than eight 

 thousand five hundred to nine thousand feet 

 high ; and this is believed to emphasize the 

 evidence of the absence of ice-action in the 

 valleys and plateau flanks. 



The region is one of extinct volcanism, 

 the action of which, though small compared 

 with that we know of some other regions, 

 has been great compared with what is seen 

 in most of the volcanic districts of Europe. 

 The phenomena are of the most varied kinds, 

 and relate to eruptions of which the oldest 

 go back to the middle Eocene, while the 

 latest " can not be as old as the Christian 

 era," and "it is hard to believe that they 

 are as old as the conquest of Mexico by Cor- 

 tes." They are subjected to a careful study, 

 especially with reference to the order of suc- 

 cession of the eruptions, and a comparison 

 of the same with the arrangement proposed 

 by Baron Richtofen. This study is followed 

 by a discussion of the origin of volcanic 

 eruptions, as illustrated by these phenomena. 

 The photographic work not having been 

 completed, has not been embodied in the 

 present volume. The text is more especially 

 devoted to the general geology, while many 

 of the details are made more clear by helio- 

 typic illustrations than they can be by mere 

 textual descriptions. The atlas contains to- 

 pographical, geological, and relief maps, and 

 a sheet showing the arrangement of the 

 faults and flexures. 



The Power of Movement in Plants. By 

 Charles Darwin, LL. D., F. R. S., as- 

 sisted by Francis Darwin. With Illus- 

 trations. New York : D. Applcton & 

 Co. 1881. Pp. 592. Price, $2.00. 



Mr. Darwin's latest study of plant-life 

 shows no abatement of his power of work 

 or his habits of fresh and original observa- 

 tion. We have learned to expect from him 

 I at intervals, never much prolonged, the re- 



