b CONTENTS. 



CHAPTER IV. 



Geology of Pit Eiver 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 cafion of Pit river. — Second basin of Pit river. — Infusorial marls. — 

 Hills of metamorphic 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 lar ge 

 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. — I"it river to Wright lake — Recent 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-serial 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. — Cafion of Des 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. — Cation 

 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. 



