in the Tertiary of California. 267 



It is about 2000 feet in height, and is mainly composed of meta- 

 morphic rocl^s of Cretaceous age,* which are in places, as we 

 ascertained, overlaid, unconformablj, by later Tertiary strata, 

 consisting of light-colored, coarse sandstones, and beds of strati- 

 fied volcanic ashes. This ridge had long been covered with a 

 dense growth of "chaparral," but just before our visit a destruc- 

 tive fire had swept over a portion of it, rendering it compara- 

 tively easy to examine a large tract of country which appar- 

 ently had never been explored. 



A careful examination of the locality where the first prostrate 

 trunks had been discovered soon made it evident that those 

 now on the surface had all been weathered out of the volcnnic 

 tufa and sandstones, which form the summit of this part of the 

 mountain ridge. Several large sihcified trees were, indeed, 

 subsequently found in the vicinity, projecting from the side of 

 a steep bluff, which had partially escaped denudation. Extend- 

 ing our explorations among the mountains for several miles 

 around, we were rewarded by the discovery of many additional 

 fossil trunks at various points, showing conclusively that this 

 Tertiary deposit contained the remains of an extensive forest 

 of very large trees, which had apparently been overthrown and 

 entombed by some volcanic irruption. Portions of nearly one 

 hundred distinct trees, scattered over a tract three or four miles 

 lu extent, were found by our party, and the information we 

 received from hunters and others, familiar with the surrounding 

 country, renders it more than probable that the same beds, con- 

 tainmg similar masses of silicified wood, extend over a much 

 greater area. 



The fossil trees washing out of this volcanic tufa wei-e mostly 

 01 great size, and appeared to be closely related to some of the 

 oiodern forest trees of the Pacific coast, especially the gigantic 

 'conifers. One of the prostrate trunks examined during our ex- 

 plorations was only partially exposed above the surface, dipjjing 

 "^th the strata about 10° to the northward. Its accessible 

 portion, evidently but a small part of the original tree, meas- 

 Jired sixty-three feet in length, and, although denuded of its 

 oark and very much weathered, was over seven feet in diameter 

 ^ear its smaller end. On a high summit about a quarter of a 

 ^ue west of this point, two other large trunks were found, one 

 about five feet in diameter, lying east and west, with thirty feet 

 01 us length above the surface. The other rested directly on 

 ^is, dipping with the strata to the north. The exposed frag- 

 ments of this trunk indicated that the tree when standmg could 

 ^ot have been less than twelve feet in diameter. These two 

 ZTa ^^ apparently fallen not far from where they were im- 

 oedded, as the bark was well preserved, both on the mam trunks 



