CHAPTER XXVI. 



TABULAE VIEW OF GEOLOGICAL STRUCTURE OE SOUTHERN NEW 



MEXICO, NEAR THE GILA. 



It may be interesting to some to have tlie strata of southern New Mexico compared with those 

 in other known parts of the globe. For the general standard the classification of M. Huot, 

 modified by Charles D'Orbigny, has been assumed. The allocation of several of the beds is 

 done with great diffidence, partly from the poverty of those strata in fossils, and partly because 

 some have been already classed under formations difi"erent from those in which they are now 

 assigned. This is particularly the case with the upper red sandstones, which have been classed 

 in TriassiCj but are here moved down into the Permian formation. 



Modern alluvium. 



Ancient alluvium. 



Pliocene. 



Miocene. 



Eocene. 



General. 



Quaternary. 



Fresh water beds 



Marine beds 



Raised beaches 



Ancient turbaries 



Loess of the Ehine 



Bone licks 



Caverns with bone remains 



Beds with diamonds and gems 



Gold, platinum, and metallic ores 



Drift and diluvium 



Erratic blocks 



Tertiary. 



Pleistocene 



Older pleiocene 



Upper bed 



Middle bed 



Lower bed 



Upper bed 



Middle bed 



Lower bed . 



eeond glauconic bed 



New Mexico. 



Gila, San Pedro, and Bravo River values. 



Around Fort Yuma. 



Micaceous sands of Gila river ; conglomerate clay of San 



Pedro river. 

 Loose sand and gravel of the desert south and east of the 



Colorado river. 



Stratified sands and clays of the Colorado desert. 

 Do. do 



Conglomerate rock of the Gila, Goat mountain, and the 

 district west of the Pimas villages. 



