Geologii of the Puget Sound Basin. — Kimball. 229 
far as Georgetown (Duwamish). In the same blutf, just 
above that suburban village, these strata give way to volcanic 
rock. To this particular occurrence reference will presently be 
made. The contact appears to be in the bed of a small cascade 
in the blulf back of the Martin place — a locality requiring 
some excavations for further investigation with reference to 
this point. 
Two miles south of Fossil bluff, on the opposite side of the 
river, at South Park, two prominent outlying survivals of the 
same formation are seen, one on the Puyallup road, and the 
other forming the eminence on which stands the Catholic col- 
lege. 
Other isolated survivals rise above the drift in the vicinity 
of lake Washington, one just north of Columbia, and the other 
just north of Brighton beach, at the water's edge. At the 
latter point it occurs as usual, under a high northeast dip. and 
contains a seam of lignite of inferior quality. Remnants of 
the same formation are said also to be present at the point of 
the opposite island (Mercur), 
A much more considerable survival of the same formation 
is a baseleveled tabular surface, about five feet above tide, at 
Alki point (Battery point). Here again, as in the Duwamish 
valley, the formation is nearly on edge at the extreme point, 
and for some distance along the beach to the south, but flat- 
tening out in that direction and gradually disappearing below 
tide. The marginal plateau has been denuded of all but a- 
thin mantle of drift for several acres around the point by the 
action of the waves, at a former stage of somewhat lower ele- 
vation, the degree of which is more exactly indicated on the 
opposite shore of the sound. Beneath the sod, as far as the 
rock could be stripped without implements, the surface is 
hard and smooth, but whether ice-scratched or not remains to 
be determined. Just back of the solid margin, at the point, 
drift bluffs rise to a higlit of 400 feet. No other basal rocks 
appear above tide beneath the drift headlands of the West 
Seattle peninsula. 
The occurrence of the same formation at Restoration point, 
on the opposite shore of the sound, is the most prominent sur- 
vival of solid basal rock within the limits of the marine basin. 
Along the shores of the peninsula terminated by that point. 
