Vol. XI] DICKERSON—PT. REYES AND SANTA ROSA QUADRANGLES 599 



PLATE XXIII 



Figure 1. View of Pleistocene terrace opposite Inverness Yacht 

 Club. The Tomales formation rests with marked unconformity upon 

 the Millerton formation in this headland. 



Figure 2. View of Tomales Bay looking northwest. Tom's Point 

 in the distance, Tomales Point beyond. On the right is a small ter- 

 race covered by the Tomales formation. 



PLATE XXIV 



Figure 1. View from the west flanks of Sonoma Mountain, Lawler 

 Ranch: Tuffs and basalt (?) in foreground; Petaluma lake beds 

 which yielded Corbicula calif ornica in the middle ground; Petaluma 

 and Petaluma Valley in the background. The even sky line in part 

 represents a marine terrace on right of picture. 



Figure 2. View of Walker and San Antonio Creek divides, about 

 five miles southwest of Petaluma showing the present divide between 

 these two streams. The Merced formation covers the divide one 

 mile northeast of the viewpoint of the picture. The rocks compos- 

 ing the hills shown in this view are all Franciscan, but the valley of 

 the Pleistocene San Antonio Creek, which once drained to Tomales 

 Bay was determined upon a Pleistocene marine terrace in the in- 

 coherent sandstone of the Merced formation. 



PLATE XXV 



Figure 1. View looking north from divide fan about three miles 

 west of Kenwood. Mt. Hood, which is not shown, is to the right of 

 this view. 



Figure 2. General view from divide fan three miles northwest of 

 Kenwood, showing Mt. Hood and a sharp peak on the south flanks 

 of this mountain. This peak is due to steeply dipping tuff-breccia 

 beds. 



PLATE XXVI 



Figure 1. Looking across Salmon Creek, three-fourths of a mile 

 southwest of Freestone. Note horizontal Merced strata. Franciscan 

 rocks occur in creek bed and by barn a quarter of a mile up stream. 



Figure 2. Looking northeast from Freestone across Salmon Creek. 

 Fair fossil collecting in creek bed on left of picture. Sonoma tuff 

 stratum is exposed near the top of the hill in the middle of the pic- 

 ture. 



PLATE XXVII 



Figure 1. View looking northwest across the mouth of Walker 

 Creek. Merced strata caps the hills on the sky-line, but Walker 

 Creek Canyon is cut chiefly in Franciscan rocks. 



Figure 2. View of Tomales Town, which is located upon a small 

 tributary of Walker Creek, Keys Creek, which has not yet succeeded 

 in cutting into the hard Franciscan rocks and its relatively wide, 

 shallow, valley is determined by the old erosion surface of pre-Mer- 

 ced age. The hills behind Tomales Church are composed of Merced 

 strata. 



