Jenicz — Albuquerque, X. Mex. — Reagan. 93 
trate every part of the plateau. This river, with the exception 
of its western branch, drains the inner arch of the Jemez 
mountains, the space between the Nacimiento mountains on the 
west and the Cochiti range on the east. The tributaries of the 
Jemez are mountain streams and usually have running water 
in them ; but, in the lower course of the river, the water seeps 
into the sand and the channel is almost always dry. Its west- 
ern branch, Salt river, drains the Fort Union formation, and 
the Puerco beds to the west of the Nacimiento mountains. It 
occupies a wide flat-floored valley with canyon-like slopes. In 
its lower course it flows along the dowli throw side of Mesa 
Blanco. The tributaries of the Jemez on the north occupy deep 
narrow canyons. Their source is in the ,rhyolitic flows 
8000-1 1000 feet above sea level; each has cut its channel 
through the volcanic debris into the Upper Carboniferous ; and 
each in its lower course has chiseled the whole or a part of its 
channel from 1300- 1600 feet in depth in the Red Beds. The 
Jemez Tributaries are noted for their medicinal springs. 
Age of the Jemez River. — The probable life history of the 
Jemez river is most conveniently presented under the following 
subdivisions of its drainage area : First, the Jemez and its 
tributaries to the north of the Indian village of Jemez ; second, 
its western branch, Salt river; third, the Jemez river below 
Canyon de los Jemez. 
The Tributaries of the Jeuie:: River at the North. — The 
tributaries of this river to the north of the Indian village 
of Jemez all have their sources in the high rhyolilic plateau of 
of Jemez mountains. On leaving this plateau each has cut a 
deep but narrow canyon. The upper part of each of these 
canyons is in Carbonife»"ous rock; its lower part in the Red 
Beds, each canyon in its lower course often being more than 
1200 feet in depth. At canyon de los Jemez, Guadalupe and San 
Diego creeks which have gathered in all the upper tributaries, 
except Vallecieto creek, unite and form the Jemez proper. At 
this point the united river enters the site of a Tertiary 
lake, probably at an earlier date a Cretaceous lake which was 
silted up by the rivers of the upper country. There is no evi- 
dence that these streams occupied their present site in Jurassic- 
Cretaceous times ; but, as there is no evidence to the contrary 
and as deposits of Jurassic-Cretaceous age were laid down in 
