64 R' W< Chaney 



The presence of a typically temperate forest in Alaska during 

 the Eocene therefore makes possible the assumption that a simi- 

 lar assemblage occupied the uplands in Oregon and California 

 at the time that the Goshen, Comstock, and other subtropical 

 forests were living in the lowlands and shedding their leaves 

 into adjacent basins of deposition. Unquestionably, there were 

 differences in detail between these contemporary forests of high 

 altitudes and high latitude; in the upland forest, Pseudotsuga 

 or Abies may have taken the place of northern Sequoia as a 

 dominant in the same way that Pinus and Abies supplant the 

 dominant Picea of high latitudes in the subalpine forests of 

 middle latitudes today. But the general aspect of the Eocene 

 forest of the uplands may be reconstructed on the basis of the 

 contemporary floras at high latitudes. Of further significance is 

 the fact, already mentioned, that this Eocene vegetation of high 

 latitudes, presumably deposited near sea level, and the Eocene 

 vegetation assumed to have been present in the uplands of 

 middle latitudes, have a definitely Miocene aspect. The up- 

 land vegetation of Oregon and California during the Eocene 

 epoch did not become part of the fossil record because it was 

 destroyed in the course of transportation toward areas of deposi- 

 tion in the lowlands. With the lowered humidity and tempera- 

 ture of Miocene times, it was shifted downward toward sea level 

 from the uplands, until it came to occupy the sites of deposition 

 in which the earlier floras had accumulated in the Eocene. At 

 the same time the southern limit of the high-latitude forest was 

 shifted down from Alaska into Oregon and California. There- 

 after this temperate flora entered the fossil record as the well- 

 known redwood forest of the Miocene. Certain differences may 

 be recognized between the middle-latitude Miocene flora and 

 its high-latitude Eocene equivalent. But these are no greater than 



