Page 7 - edwards1947

General:

The formations in the Del Valle area oonsist entirely

of eedimentaey rocks riu1ging in age from .Miocene to Reoent.

The rooks exposed at the surface in the area are Pliocene sands,

sandstoi'ltus, siltstones. and eh.alee, with local "kleistocene sands

and gravels. lo igneous or metamorrhic types are to be found

except as oonglomerat1c boulders.

Modelo formation, Ul!per Miocene:

"The Modelo is not exposed at tbe su.rtaoe in the Del Valle

area though 1 t is penetrated by the wells and is produotiv,,-

The oldest sediments penetrated in the Ramona and Del Valle

field.a are the brown shales and sands of the Mohnian stage of

the upper .Miocene• Over 2000 feet o t Mohn1an beds have been

penetrated 1n the area. R. :re. Havenstrite's Barnes No. 2 well.

wh1ob was drilled to 9867 feet, (Structure Seotion B•B') and

the Superior 011 Company's and the British-American Oil Fro•

duc1ng Company's Handy no. l, (Structure Seotion c-c') drilled

to 10,097 feet, are the deepest stratigraphic ~enetrationa to

1
date in the area.:; ••• •• •••••• and both penetrate t m Mohnian.
"Uppermost Mioaene Delmontian stage beds overlie the rooks

of the Mohnian age. Since paleontologists disagree as to the
exact position ot the top of the Miocene in the area, the exact

t. Malter. 3. :tt. am Wrath, w. F., 'ffe'f Vaile and mimona 011
Field.a, Los Angeles and Ventura Counties, California, Field
Trip Guide Book, joint annual meeting of AAIG, SIG, SEI>M,
PP• 37•38; t~rch, 1947.