Copper and Lead in New Mexico. — Herrick. 287 
The showing at the intersection is often very good and has 
been the cause of a great deal of profitless investment. It is 
possible to point out the places where such deposits will be 
found without doing more than to stand at a distance and 
note the points of intersection of the veins and the iron band 
so that the geologist gets credit for a great real of acumen for 
a prediction which is based wholly on a very simple metal- 
lurgical principle. 
The region described extends many miles along the eastern 
slope of the San Andreas and similar conditions occur else- 
where. It is true that a considerable amount of fine coDper ore 
occurs in these intersections and, with better means of access, 
they will no doubt be utilized, and it is rlso true that there may 
be found deeper workings where under different conditions 
of accumulation large bodies of good ore .might occur, but 
the careful investor will avoid being deceived by the surface 
showing and will beware of too general application of the 
miner's notion that mineral must "go down." 
The Caballo Moimtains. Between the San Andreas and the 
Rio Grande is a large stretch of desert plain called the Jor- 
nada del Aluerto which, from the lack of water, has long been 
a terror to the freighters and packers. Much of pioneer ro- 
mance has been woven into stories of the Joi'nada and even 
since the railroad has bridged the gulf it is still unrechimed. 
Toward the western border of the plain there is a series of 
basaltic cones from which there spread out over the plain 
larger or smaller sheets of lava, the most northern of which, 
at San Marcial, extends to the river. At this place the lava 
flows over a deposit of sand and stratified loam not unlike 
that west of Albufjuerque. This series of basaltic flows is a 
continuation of that further north in the valley but the river 
at this point has been diverted to the west. The occasion for 
this diversion is apparently the elevation of a minor axis on the 
western border of the Jornada forming the San Cristobnl and 
the Caballo mountains, in Sierra county. 
Both these ranges rise quite abruptly from the eastern edge 
of the river valley to a variable hight. The Caballo range 
is the higher and is that with which we at present have to do 
and is mentioned in this connection to illustrate the modifi- 
cation of the same method of ])recij)itation as that seen in the 
