Page 12 - edwards1947

Ostrea bed that appears to be quite consistent tbrou.ghout

the Del Valle area south of the Ramona faul 1;. There is a

question in the writer's mind as to how much o:f the top of the
l?ioo is missing owing to the d1soonform1ty between the Saugus

and the 12100.
Farther east. in tm v1o1n1ty of Elstmre and 1;100 Canyons.

8
Ke'!!,/ describes an overlap type of diaoonformity bet>.veen the
f ioo and Saugu.a torma tion a. Al though the exposures are not

good, this overlap does seem to be present in the Del Valle

area south of the Ramona fault ( see Structure Section A•A •) •

However, it was not possible to detect an overlap north ot the
f'aul t.

Below the Ostrea bed are more sandstones, ooarse grained•

white to buff, massive; poorly sorted and fossiliferous with

some arose-bedding. These grade into the lower Pico, wh1oh 11

estimated by the writer to be about 1000 feet th1olt. The lower

?ioo e posel between the two Canyons is identical with the

lower I'ioo exposed by the Del Valle t hruet, except that the

basal conglomerate is not seen at the Sllrface.

'?he sar.dstone unit {upper ?ioo) contains nUJ'Jl?rous mesa•

fossils horizons ot Eliooene age. A few speo1ee found here

area Dendraster diegoensis Kew, Anadara oamuloens1s, Ostrea

lur1da Carpenter, Ostrea vesl!rtina Conrad (?), ;~ecten bellue

Conrad, ?atinopeoten oaurinue (Gould), O,hlamzs (?) hastatue

a. tihv, w. ~. W., t1eo1ogJ and 011 rosources of' a part of toa
A.tlgelea and Ventura Counties, Caiifornia, u.s.o .• s. survey
Eull. f53t PP• 86•89, 1924.