1914] Buwalda: Pleistocene Beds in the Mohave Desert 451 



youngest fanglomerates belong to a time immediately preceding 

 that of laeustral deposition. 



About seventy-five feet of coarse fanglomerate is reported 

 by Messrs. Moody and W. F. Jones to overlie the Manix Beds 

 on the flanks of the Cady Mountains south of Afton. Where. the 

 unflexed beds abut against the steep slopes of the Cady Moun- 

 tains one to two miles east of Camp Cady, perhaps twenty-five 

 feet of later fanglomerate overlies the beds. As Manix Lake was 

 at few points bordered by steep slopes and the downcutting of 

 the Mohave River in this region has influenced the tributaries 

 to cut rather than to deposit, the accumulation of fan materials 

 upon the Manix Beds has not been extensive. 



Fauna. — The fossil material collected from the Manix Beds 

 represents six species of mammals, one or more species of birds, ^, 

 four species of freshwater molluscs, and one or more species of 

 fish. Of this fauna the mammals, because of their short range 

 in geologic time, are the most important in age determinations. 

 The six forms comprise a large horse quite certainly Equus., a 

 somewhat smaller horse, a large camel, a smaller camel, a mas- 

 todon or an elephant, and an antelope, the latter two each known 

 by a single digital element. The fauna is considered by Pro- 

 fessor J. C. Merriam to be of Pleistocene age. The stage of the 

 Pleistocene represented by the fauna is, however, difficult to 

 determine because of the paucity of species, and lack of knowl- 

 edge regarding the dates of extinction of the forms represented. 

 Because of the supposition that camels became extinct in North 

 America before Glacial time, the fauna may represent an early 

 stage of the Pleistocene. 



Deformation op the Fanglomerates and Lacustral. Beds 



Deformative movements of considerable magnitude occurred 

 in the Manix Lake region just before the appearance of Manix 

 Lake, and again shortly after the deposition of the lake-beds. 



The evidence of pre-lacustral folding is seen in the somewhat 

 irregular anticlinal arching of the fanglomerates on a north- 

 south axis passing through Cave Mountain and the Cady Moun- 



