THE 
AMERICAN GEOLOGIST. 
Vol. XXXII. NOVEMBER, 1903. No. 5. 
GEOLOGY OF THE FORT APACHE REGION IN 
ARIZONA. 
By Albert B. Rbagan, Blooming-ton, Ind. 
PLATES XXIX-XXX. 
CONTENTS. 
Literature 267 
General Description 267 
Scenery 268 
Structure 269 
Sedimentary Rocks 269 
Stratigraphical Sections 270 
Stratigraphy 275 
The Archean 275 
The Algonkian 277 
The Upper Silurian 278 
The Devonian . 
278 
The Lower Red Wall Group 279 
The Upper Red Wall Group 279 
The Aubery Group 280 
The Cretaceous (?) 280 
The Tertiary /, . 2 so 
The Quaternary 281 
The Post Glacial. 
283 
Resume 285 
Geography and Physiography 286 
Mountains 286 
The Fllison Dome 286 
The Sierra Ancha 287 
The Mogollon Range or Mesa 287 
The White Mountains 288 
The Nantan Mountains and Plateau 288 
The Plateau- Canyon Creek Escarpment 289 
The Apache Mountains 2gg 
The Pinal Mountains 290 
Buttes 291 
Drainage 291 
Course of Streams Previous to Faulting _".i.t 
Diverting of Drainage by Faulting and Consequent Laking.. .... 293 
