Santa Barhara Channel-, etc. — Yates- 45 
California, from the San Miguel off point Conception to the 
eastern extremity of the Anacapas, is composed of a founda- 
tion of black vesicular basalt, upon which rest the later forma- 
tions of trachyte and other varieties of volcanic rocks. 
In many places the older flow of lava has evidently been 
broken up into irregular fragments, and cemented by the sub- 
sequent flow of intrusive lava, which formed a softer rock than 
the older basaltic formation ; hence where this volcanic breccia 
is exposed to the action of the atmosphere, the intruded ce- 
ment has disintegrated more rapidly, than the included frag- 
ments of the older formation, thus freeing the enclosed frag- 
ments which form the debris at the bases of the perpendicular 
cliff's along the shores of the islands. At other points, (for exam- 
ple see sketch No. 1 on north side of the middle Anacapas) 
we see the black basalts forming the foundation of the inlet 
up to about 20 feet above the surface of the water ; the soft 
trachytic rock which formerly covered the basalt, has been 
eroded, leaving only a rounded elevation in the centre. A 
short distance from this islet the foundation is capped by a 
variety of irregularly stratified rocks ; First, by a gray basalt ; 
then by a lighter gray ; then a dark line of much weathered 
trachyte, finally, by a light colored greenish gray stratified de- 
posit Avhich forms the present surface of the island. 
This formation is shown in sketch No 2, where is also shown 
a wall of intrusive rock of a dark rusty color, capped by a 
warm grayish brown. This interesting exposure can be 
favorably studied from point Lookout, (A. sketch No. 1) ; 
which point may be reached by following a well made trail 
starting at the settlement and following an easterly direction, 
skirting the northerly line of the uplands, gradually tending 
downwards until a point is reached from which an excellent 
view of the west island may be had, also of the natural arches 
and entrances to the caves, — and higher up in the bluff's of the 
small wind-worn caves, the varied points and irregularities of 
outline, the wealth of coloring of rocks, plants, ocean, sky, 
and even the sea-weeds adding no unimportant item to the 
panorama. 
As seen from this elevation the colors of the clear, calm 
water of the ocean shade off" from bright yellowish brown and 
brilliant green at the surface, to the depths where the darker 
hues of brown and green are blended. Even the molluscs 
