266 The American Geologist. November, 1903. 
DESTRUCTION OF LAKES AND THE PRESENT SALT RIVER DRAINAGE. 
Springs 294 
The Extinct Springs 294 
The Common Springs 294 
The Hot Springs 295 
The Salt Springs 295 
Intrusive Rocks 296 
Dikes 296 
The Plateau-Canyon Creek Dike 296 
The Salt River Dike 296 
Dikes and Veins in the Vicinity of Globe 297 
The Ellison Dike 297 
The Kelley Dike 297 
The White Mountain Dikes 297 
Laccoliths 298 
Extrusive Rocks 298 
Volcanoes 298 
Volcanic Buttes 298 
Lava Flows 299 
Diorytes (and Diabases) 299 
Trachytes and Rhyolytes 299 
Rhyolyte of the Apache 'Mountains 30u 
Rhyolyte of the Pinal Mountains 301 
( itlur Patches of Rhyolyte 301 
The Basaltic Lavas, including the Sanidin-Doleryte Type 301 
Economics 
Climate 303 
Soil 303 
Vegetat ion • 303 
Irrigation 304 
Mineral Resources 305 
Coal 305 
Building Stone 305 
Salt 305 
Gold, Silver and Copper 305 
Oil 306 
Mining 306 
Placer 306 
Mines 306 
Water Power 307 
References 308 
The following pages are derived from studies carried on at 
intervals during the writer's stay on the White Mountain 
Apache Indian reservation as government farmer. While there 
he took work by correspondence in the University of New 
Mexico; and the original reports on which this paper is based 
were submitted to Dr. W. G. Tight, president of that univer- 
sity, at whose request this paper has been prepared for publi- 
cation. 
In submitting this paper the writer gratefully acknowledges 
the personal aid rendered him by Drs. J. W. Beede and F. V. 
Marsters while the manuscript was being written. 
