Page 20 - elizondo1953

In general, it consists of' light yellcn.r, ros<lium to coarae grc1.ned thick
11
bedded to massive biotite•bearing 0.1•kosse 11 interoodded with thln to

madium,.,,thiok layers or conglomerate. Thin bed#iJ (about one foot in
maximum thickness) of drab-brown shales are found more

Several. patches of' coarme, yellow conglomerates o:r the Eocene
eect:ton ere we:u exposed along tho road in san Franc:l.squ:l .. to Canyon,

2.,2 miles north of st., Francis Da:rn11 In genera.1 11 t.hey are 15-20 feet
thick$ and consist of' 75..;•90 ·per cent. o.f pebbles, cobbles an.d bm1liier11i

very well rounded, the nature of which is larsQiy that of mon~<)nj, ,

diorites, qua.rt~ioritee and porphyry andeaitesi a .t'ew cobbles a.re ma,d~

up of quartzites and porhaps grey crysta.lliria limestoneq The subord:i.11ate

matrix is quartz•feldspathicl' These conglomeratea are overlain by a

thick series of ;ye 11~ 11 ma.ssi ve a.r koee s, a.nd, are f'aJil ted again1::it

Eocene ('./' )-Miocene ( 1) red bed a.,

little ·cnimi;i:e 5,n lithologic ft;i,cies among

Eocene rooks, bot,h laterally and ,rerti.caJ.ly, ·J::.heir predominant com-

poc,d:tiorl, great thiclmces nnd the areal e:.~tentp su.ggeat £'onnAt1on on 1:1,

st1bsiding area of' deposition adjacent to rapidly rising gra.ni.tic ranges

which perhaps lay to the north and no:i:>thweste 'Ine or:tgin of the volcanic

constituents occurring in the conglomerates is unknown~

Eooena(?)-Miocene(?) rocks11r

Continental deposits o.r Eooe:ue(?)-Hiocene(?) age are eJrten-

sivcly distributed in the area. ma.pped. They cove:r apnroxi:r.1ately 5

square miles, are separated from older fo1"'lllations by faults to the