40 J. LeConte—Hxtinet Volcanoes about Lake Mono. 
dicular. The lower portion of the cliff, being covered up b 
talus, is not represented. It is seen that nearly the whole is an 
ordinary modified drift, composed of irregularly stratified sands 
and clays, cc, intermingled with layers of pebbles and _ gravel, 
bb ut there are other parts that deserve more special notice. 
The stratum e is a fine light-colored olay, through which runs 
; 1, a deep chocolate- brown 
pO ae een lamina scrolled in the 
SEP S822 Oe MOTB BG ate acess, most complex and beau- 
sa: tiful pattern ; the stratum 
d is also strongly crum- 
led. Thi 
scrolling of the sisntis 
HO pr On Oe oO RO Oe ONS © B97 e 
e 20. ocala 4 ee "ox 10. 
bs Or, 10.4 O- Or. O29 Oe 009 wo oF 20. > PA 
—, a — s “— — —_ — 
? 
So Sea ees - bean aptodnced: by 
So ee ier a ee ee aldernately advancing 
ee es ee and retreating glacier ; 
SNS NNN oe oat — drop- 
oe ee oes ; ing material, to be car- 
sce habtie ane ee ee m and deposited by 
cc = fine sand and clay stratified. the river which flow 
d = strata crumpled by moving strata. a its snout, now ad- 
on iiaeeem ice ing and crumpling 
the finer material of the lake botedins: "Tt may be difficult to 
explain the details of the process, but I think it will not be 
doubted that the whole is a distinctly marked drift-deposit. 
Many other similar sections were observed; some of which 
go sibs feet thick. 
thick, ut it is es sae thicker, as va thins off on ro mat- 
gin of the perpendicular cliff by falling, a thus contributes 
to the talus at its base. It is evident that the whole material 
of the section was deposited during Ts times, except 4, — 
which was drifted over the bared lake bottom since that time. 
But judging from the immense monetey of this loose material, 
covering as it does the whole plain many feet deep, it seems im- 
possible that it is the mere result of if disintegration o of the vol- 
ri 
ea 
