352 
MINING GEOLOGY 
to point out that though our reserves would not meet our present 
rate of consumption demands for twenty years if they could be 
taken out of the ground fast and cheaply enough to supply our 
market (a conditioning clause that has generally been lost sight of 
by the press and the public), this country will be producing oil for 
as long as seventy-five years to come.” 
In reckoning available oil supplies the enormous potential yield 
of oil shales of some of the western states should not be forgotten. 
These may produce ten times as much oil as remains in the ground 
in other parts of the United States. KeyES 
Verity of the Pipe-Vein. Recent controversy on the theme 
of whether or not there actually exists a pipe-vein type of ore- 
body recalls to mind an inspection, some years ago, or a unique 
silver deposit on the San Augustine plains a few miles from the 
foot of the lofty Sierra Magdalena in central New Mexico. If 
ever there be ore deposit answering to such description as pipe- 
vein this one surely appears to fill the bill. Although its rarety 
and small importance are fully recognized the occurrence itself 
is of no little interest as indicating that according to the most ap¬ 
proved modern classification of ore deposits it should find a place. 
“Float” samples of very rich silver glance were discovered by 
some prospectors. After considerable searching over a large area 
this float was traced to a low butte, now called Silver Hill, where 
after a little digging the country-rock was disclosed with the ore 
encased.. The rock was apparently a granodiorite, or porphyry as 
the miners more commonly term it. The ore-spot was opened up 
and the material assayed, the results giving extraordinarily high 
values in,silver. 
The “ore-body” was found to be oval in cross-section, about 
12 by 18 inches in size, but ran straight downwards. A shaft 
was begun and the ore-pipe followed to a depth of 340 feet. At 
this depth, according to reports, water stopped further sinking 
because of lack of suitable pumping machinery, and also for rea¬ 
son of the fact that the ore lead began to flatten greatly. Accord¬ 
ing to all accounts this ore-pipe was associated with no other ore- 
deposits of any kind, nor with any fissures. 
A part of the pipe assayed as high as 3600 ounces of silver 
to the ton; and 20 per cent copper. 
Keyes 
