CONTENTS. 



CHAPTER IV. 

 Geology of Pit Elver and Klamath basins. 



Pit River basins. Lake-like character of the lower basin. Proofs that it has once been a lake. Infusorial sediments 

 deposited by its waters. Range forming the upper canon of Pit river. Second basin of Pit river. Infusorial marls. 

 Hills of inetumorphic slate, greenstone, porphyry, and trap bordering Pit river. Geology of the country about the head of 



Pit river. Hot springs and infusorial marls. Klamath basins typical illustrations of the geological structure of a large 



area. Common features of the region lying east of the Sierra Nevada and the Cascades. Not one but many basins. 

 Klamath basins once lakes. Local geology. Fit river to Wright lake Eecent volcanic cone. Cliffs bordering Rhett lake 

 of sandstone and trap. Efflorescence on the shores of Rhett lake. The Natural Bridge a fault. Infusorial marls of Lost 

 river and lower Klamath lake. Metamorphic form of these marls, resembling jasper. Geology of the shores of Klamath 

 lake. Basaltic conglomerate on Klamath river. Infusorial marls. Pumice. Trap ranges south and east of Klamath 

 marsh. Pumice plain between Klamath marsh and the Des Chutes river. 



CHAPTER V. 



Geology of the Cascade mountains. 



Panoramic view of the Cascade mountains. -Sierra Nevada and Cascade mountains. A wall crowning the western 

 margin of the great central plateau. Structure and origin of the Cascade range. Main crest near its eastern margin, a line 

 of volcanic peaks. More westerly mountains, metamorphic slates. Local geology. Crater Pass. Evidences of glacial 

 action. Glaciers once descended far below the present snow line. Extent of glaciers in the Cascades.- Conditions under 

 which they must have been formed.- By elevation or change of climate? Evidences of elevation. Sub-a;rial excavation 

 of mouths of rivers. Depression of temperature would produce greater precipitation of moisture. Streams flowing from 

 the Cascade mountains formerly larger than now. Canons of those streams not rifts but excavations. 



CHAPTER VI. 



Geology of the Des Chutes basin. 



Compound nature of this basin. Its subdivisions similar in structure to those of Pit and Klamath rivers. Trap 

 plateaus. Volcanic tufas and infusorial marls. Local geology. Plateau east of the Three Sisters. Cafion of Mpto-ly-as 

 river. Mount Jefferson. Congealed lava stream. Castle Rock. Columns of basaltic conglomerate capped with blocks of 

 trap.- Tufaceous strata of Mpto-ly-as river. Canon of Psuc-see-que creek. Picturesque appearance of the colored tufas 

 and concrete. Trunks of coniferous trees imbedded in tufa. Columnar trap covering the tufas.- Warn Chuck river. 

 Hot springs. Gelatinous silica. Metamorphosed tufas. Onyx, opal, agate, silicified wood. Warn Chuck mountains. 

 Metamorphic slates. Quartz and chalcedony. Nee-nee springs. Metamorphosed marls. Ribband jasper. Plateau of 

 Tysch prairie. Tysch mountains. View of Mount Hood. Canon of DCS Chutes river. Mounds. Hills of infusorial marl 

 south of the Columbia. 



CHAPTER VII. 

 Geology of the country bordering the Columbia river. 



Region east of the Cascade mountains. General features apparently similar to those of Des Chutes basin. Local 

 geology. Dalles of the Columbia. Sedimentary infusorial deposits. Their fresh water origin. Their age. The canon of 

 the Columbia. General features. How formed. Local geology. Horizontal strata of trap. Submerged forest. Cascades 

 formed by slide from mountains Conglomerate. Silicified wood. Tertiary strata below Cascades. Country bordering 

 the lower Columbia. General features. Willamette valley. Local geology. Western slope of the Cascade range. Cauon 

 of McKenzie s fork. Marks of glacial action on Mount Hood. Trap, scoria, ashes, &c., from Mount Hood. Trap and 

 sandstones of Willamette valley. Erosion of sandstones. Lignites near St. Helens. Terraces. Coast mountains. Sand 

 stones and shales of Astoria. Fossils. Age of the deposit. Port Orford. Tertiary sandstones. Trap. Gold. 



