MINING GEOLOGY 
343 
and soils in order to locate small areas where the clay is readily 
accessible. ^ 
In the non-glacial areas of Cambric sandstones the detailed 
stratigraphic sections already published prove of great practical 
value, since in this area deposits of Cambric shale are the only 
material available for surfacing the sand roads. With this strati¬ 
graphic knowledge as a basis, the geologist studying road materials 
must select the particular sites where the material needed can be 
secured and delivered on the road with the least possible expense. 
In driftless southwestern Wisconsin, which lacks the wealth of 
readily accessible road material to be found in much of the glaci¬ 
ated area, search is made for limestone of suitable quality and 
availability. The sandstones are studied to find a formation suit¬ 
able for fine aggregate for concrete, or as surfacing for heavy 
clay soils. Stream-gravels are located for use as surfacing and 
for concrete aggregate. 
In the areas of thin drift overlying granitic rocks, the glacial 
material is not of much value for road material. Search must 
therefore be made for disintegrated granite suited for road sur¬ 
facing, or for fresh granite which can be crushed for concrete. 
Investigations of this kind are especially valuable to the High¬ 
way Commission, because such surveys save money; valuable 
to the geologists because they add greatly to geological knowledge 
of the State. They help the geological profession, since these sur¬ 
veys have convinced a large number of people that geology is prac¬ 
tical and that by its application large amounts of money may be 
saved. Bjjan. 
New Borate Field in Nevada. Announcement of the “recent^* 
find of important borate deposits in Callville Wash, in south¬ 
eastern Nevada, is only one of the many illustrations of the su¬ 
preme complacency with which Government bureaus attempt to 
impress the public with some valid raison d^etre. Borax mining 
is singularly free from scientific dependence. Although the 
famous 20-mule team advertisement is largely fiction, and finds 
greatest activity in traveling around the grounds of the St. Louis 
World’s Fair, its very existence prevents the normal exploration 
of the Death Valley deposits. 
After the discovery of borate crystal in extensive beds, in the 
