GEOLOGICAL PAPERS. 141 



NOTES ON THE TOPOGRAPHY AND GEOLOGY OF 

 NEW MEXICO. 



By J. J. Jewett, Los Angeles, Cal. 

 Read ( by title) before the Academy, at Topeka, December 31, 1904. 



/^N the parallel of 37 degrees north, New Mexico is but fifty-four 

 ^-^ miles from southwest Kansas. The distance is measured by one 

 degree of longitude between meridians 102 deg. and 103 deg. west. 

 The geological formations bridging the interval are, no doubt, iden- 

 tical with those of western Kansas and eastern New Mexico. The 

 Cimarron river, deriving its waters from the territorial slope of the 

 Raton mountains, is the only river entering Kansas, except the Ar- 

 kansas, having its sources in the Cordilleran region. The area of 

 New Mexico is more than once and a half that of Kansas, and is 

 about measured by that of Great Britain and Ireland. Its average 

 altitude is at least 3000 feet above the average of Kansas, and its 

 lowest parts are above the mean of Kansas. 



The geology of New Mexico is less certainly known than that of 

 any other political division of the geographically connected United 

 States. The present paper will only call attention to certain pictur- 

 esque features of topographic and geologic interest. 



Unlike Kansas, the Paleozoic formations in the territory would be 

 a matter of inference only, except for its mountains and the canyons, 

 their derivatives, for those early deposits are deeply covered with 

 Mesozoic and Cenozoic strata elsewhere than in the vicinity of these 

 elevations and trenches. Fortunately, Kansas, without mountains 

 within her boundaries to destroy the vastness of her agricultural 

 capacities, revels in the successive disclosures of her strata, from early 

 Carboniferous to late Alluvial, giving almost unexampled access to 

 the geological benefactions of all time. This condition to human 

 advantage, however, is to be credited to the slow uplifting agency of 

 the Ozarkian region to the east and southeast of her present borders. 



The territory is ridged and cross-ridged with mountain segments, 

 which together constitute geographic ranges for hundreds of miles, 

 but continuous sierras end in the middle of the north half, in the 

 Sangre de Cristo range, apparently the oldest orographic monument. 

 The range culminates in an altitude of over 13,000 feet, seventy-five 

 miles south of the Colorado line and thirty miles east of the central 

 meridian of the territory, the 106th. From this point it broadens 

 and splits into three sharply crested, nearly parallel ranges, of which 

 the eastern is longest, and which extends fifty-five miles further south. 



