34 
RATON RANGE 
Fésher Peak 
Ocate Mesa 
PLATEAU 
Las Vecas 
CANADIAN VALLEY 
Fic. 1.—Substructure of the Mesa de Maya Plateau; New Mexico. 
CHARLES “RVKEV ES, 
The most remarkable of these ele- 
vated plains is the Mesa de Maya, in 
northeastern New Mexico. Its exten- 
sion is the flat crest of the Raton Range. 
The greater part of the mesa is formed 
bya thick basalt plate, 500 feet in thick- 
ness, resting on the beveled edges of soft 
Laramie shales and sandstones. This 
mesa is gently inclined to the eastward 
and extends from the Rocky Mountains 
a distance of more than one hundred 
miles to beyond the Texas line. (See 
fig. 1). It is 3,500 feet above the next 
extensive plains-level below, known as 
the Ocate mesa, which in turn is 500 feet 
above the general plains-surface of the 
region, or the Las Vegas plateau. It 
appears that the Mesa de Maya repre- 
sents practically a Tertiary peneplain 
which existed at the time of the general 
elevation of the region. At the town 
of Raton its surface is now 9,000 feet 
above tidewater. Were it not for the 
great lava-field the remnants of which 
constitute this plateau-plain there would 
today remain no undoubted traces of 
the old peneplain in this part of the 
country." 
That the Mesa de Maya is# the 
remnant of what is essentially a pene- 
planation-level which, perhaps, once 
extended over much, if not most, of 
the present desert region around the 
southern end of the Rocky cordillera, is 
strongly supported by a number of facts: 
(1) The foundation strata, both hard 
t Proc. Iowa Acad. Sci., XV, p. 221, 1908. 
