464 



University of California. 



I Vol. 3. 



The dark brown color of the flood-plain deposits of the forty- 

 five foot terrace is due to the presence of much carbon. The 

 soil was prevailingly dark brown. It implies a luxuriant vege- 

 tation and a cool, moist climate. As I will correlate this lower 

 terrace with some portion of the last great glacial epoch, it will 

 appear that the lowering of the temperature which caused the 

 great extension of the Wisconsin glaciers, changed the soil of 

 Northwestern California from red to brown. Since the glacial 

 period has terminated the soil has gradually become lighter in 

 color, as evidenced by the lighter tint of the Modern silts. 



Professor D. P. Penhallow's report to Mr. Knowlton on the 

 fragments of wood from the Ferris and "Wilder Mines is as fol- 

 lows. Set No. 1 is from the Wilder Mine, and Set. No. 2 from 

 the Ferris Mine : 



"I have completed an examination of your specimens and 

 have to report that they are all Coniferous. They present some 

 interesting features of preservation, which I shall discuss at a 

 later date in another connection. I have numbered the speci- 

 mens from 1-7. 



No. 3, Set No. 1, is Pseudotsuga macrocarpa. 



No. 4, Set No. 2, is Juniperus californica, 



Nos. 1 and 2 of Set No. 1 represent a species of Juniperus 

 which could not be determined on account of structural altera- 

 tions, but there is reason to believe it may be J. californica. 



No. 5 of Set No. 2 is not determinable, owing to the very 

 high state of alteration, which would not permit of sectioning. 



Nos. 6 and 7 of Set No. 2 are either Pseudotsuga, Picea or 

 Larix. It is impossible to decide definitely between them, but 

 the probability seems to lie in favor of the first. 



With respect to the relation to existing representatives of 

 the same genera, it is to be noted that Pseudotsuga" macrocarpa 

 is still extant in the same region. Juniperus californica appears 

 to have receded somewhat toward the south, as its northern 

 extension is at present confined to the valley of the Sacramento, 

 thence southward along the Coast Range. While these facts are 

 not in any way conclusive, they suggest the possibility that 

 present conditions are slightly more boreal than during the 

 time our trees were living. This would seem to agree with the 



