ACADEMY OF SCIENCES. 295 



Donations to Librcary : Map of the Pioche Mining District, 

 Nevada, by E. Durand. 



Donations to the Museum : Specimens of Californian and Alaskan 

 Woods, from W. G. W. Harford. A collection of Insects from the 

 Sierras, by George Davidson. Specimen of precipitated Copper, 

 from a mine at Copperopolis, by William Burling. 



The specimen of precipitated copper, donated to the Academy, 

 was taken from a copper mine at Copperopolis, which had par- 

 tially filled with water ; the copper had precipitated upon a pick- 

 iron, and the iron subsequently dissolved, leaving the copper as a 

 matrix or external cast. 



Mr. Goodyear presented the results of his observations during 

 a recent trip to the North, of wliich the following is an abstract : 



Notes on the Geology of the Coast of Oregon. 



BY W. A. GOODYEAR. 



On bis trip to Koos Bay, by the stage route, little was noted beyond what is 

 described in the geological report, except the fact that the canon of the upper 

 Sacramento River had long existed prior to the flow of basaltic lava which 

 ouce ran for fifteen or twenty miles along its channel ; the deepening of the 

 canon since that epoch having been comparatively small, amounting to an esti- 

 mated depth of 200 to 400 feet below the lava flow. 



Between the Rogue and Umpquah Rivers, the country is very mountainous 

 and heavily timbered : but nothing of volcanic character was seen in Southern 

 Oregon, except two or three flat-topped hills near Jacksonville, and locally 

 known as the " Table Rocks, " of which the capping is probably basaltic lava; 

 hence to the lower Willamette Valley no other volcanic matter was seen. 



From Roseburg to Koos Bay, distant sixty-three miles, the road passes over the 

 Coast range of mountains, attaining an elevation of about 4,000 feet. From 

 Roseburg for 25 miles to the eastern flank of the mountains there are compara- 

 tively low hills and small fertile valleys ; the former covered, but not heavily, 

 with oak, which gives place to a dense growth of coniferous trees as the alti- 

 tude is increased and the coast approached. The oak-timbered hills are meta- 

 morphic rock with some semi-serpentine, but the exposures are rare along the 

 road travelled. The higher mountains and the whole country to the westward 

 consist of heavy-bedded sandstones, with little shale, and entirely unaltered. 



The peculiar feature of the country adjacent to Koos Bay is the numerous 

 tide water sloughs which stretch ten to thirty miles inland ; the same general 

 features are exhibited at the lower reaches of the Coquille and Umpquah Rivers. 

 The region traversed by these sloughs appears to have been a table land whose 

 present height is from 200 to 800 feet above the sea, with evidence of oscilla- 

 tion in some cases of even more recent date than the excavation of the sloughs. 



