Oil in the Monterey California Formation Los Angeles to Santa Maria, California July 20-24, 1989

60 Pages·6.726 MB·English

Oil in the California
Monterey Fonnation
Los Angeles to Santa Maria, California
July 20-24, t 989
Field Trip Guidebook T3 t t
Leaders:
Thomas MacKinnon, Editor; and J.W Randall
Associate Leader:
Robert E. Garrison
American Geophysical Union, Washington, D.C.
Copyright 1989 American Geophysical Union
2000 Florida Ave., N.W., Washington, D.C. 20009
ISBN: 0-87590-600-1
Printed in the United States of America
COVER Thin-bedded sequence of chert, porcelanite, mudstone and dolostone;
Monterey Formation exposed in beachcliffs approximately 1 kilometer north
of Point Pedernales, central California coast.
CONTENTS
ORIGIN OF THE MIOCENE MONTEREY FORMATION IN CALIFORNIA
THOMAS C. MACKINNON 1
PETROLEUM GEOLOGY OF THE MONTEREY FORMATION IN THE SANTA MARIA
AND SANTA BARBARA COASTAL AND OFFSHORE AREAS. • • • • • •• THOMAS C. MACKINNON 11
THE MONTEREY FORMATION AND BIOSTRATIGRAPHX: AN OVERVIEW
MICHAEL P. DUMONT 28
ORGANIC GEOCHEMISTRY OF THE MIOCENE MONTEREY AND EQUIVALENT
FORMATIONS IN FIVE CALIFORNIA BASINS•••••••••••• MARGARET H. PYTTE 33
A. M.IN.ER.AL.O.GIC.AL. C.L.AS.SIF.IC.AT.IO.N.OF. M.O.NTE.RE.Y.LI.TH.OL.O.GIE.S.
ALDEN B. CARPENTER 37
MONTEREY DEVELOPMENT - ONSHORE AND OFFSHORE SANTA MARIA BASINS
ROBERT H. SKILLIN 41
POINT ARGUELLO FIELD FORMATION EVALUATION OF FRACTURED
MONTEREY RESERVOIR. • • • • • • • • • • • • • • • • • • J. L. FISH 45
RESEARCH AND TECHNOLOGICAL SUPPORT FOR PETROLEUM EXPLORATION,
DEVELOPMENT AND PRODUCTION. • • • • • • • • • • • • • • •• LINDA D. RAEDEKE 50
NOTES ON SELECTED FIELD TRIP STOPS. • • • • • • • • • • •• THOMAS C. MACKINNON 52
v
Leaders:
Thomas C. MacKinnon
Chevron USA
P.O. Box 5042
San Ramon, CA 94583
J. W. Randall
Chevron USA
P.O. Box 6917
Ventura, CA 93006
Associat~ Leader:
Robert E. Garrison
Earth Sciences Board
University of California
Santa Cruz, CA 95064
vii
IGC FIELD TRIP T311
ORIGIN OF THE MIOCENE MONTEREY FORMATION IN CALIFORNIA
by Thomas C. MacKinnon
Chevron U.S.A., San Ramon, California
INTRODUCTION Garrison and others (1987 and in press) on
phosphatic rocks and paleoceanography;
Diatomaceous rocks and their diagenetic Isaacs and Petersen (1987) on petroleum
equivalents, chert, porcelanite and geology; and Snyder (1987) on structure.
siliceous mudstone are abundant in Miocene
deposits of the Pacific region. Of these,
the Monterey Formation is the best known and GEOLOGIC SETTING
most extensive. It is present throughout
large parts of the state of California California has been part of a subduction
(Figure 1) and is in places over three or transform plate margin since the Late
kilometers thick. In addition, it includes Paleozoic. Subduction appears to have been
the largest diatomite quarry in the world the dominant mode at least from the Late
and more importantly, is the source and Jurassic to Mid Tertiary times. In Late
reservoir for much of the oil produced in Oligocene times (ca 29 Ma) subduction began
California (Figure 2). to cease due to the collision of a
The origin of Miocene siliceous deposits spreading ridge with the California margin
in the Pacific region is tied to a trench (Atwater, 1970).
fortuitous combination of tectonic, climatic The change from a subduction to a
and oceanographic conditions that promoted transform margin resulted in a dramatic
biogenic productivity while reducing change of depositional patterns in
terrigenous input to coastal basins. This California that helped set the stage for
resulted in rapid accumulation of relatively Monterey Formation deposition. In the Late
undiluted biogenic sediment, not only Oligocene-Early Miocene, the California
siliceous but calcareous as well, during the margin experienced rapid downdropping and
Miocene times. the development of deep marine coastal
Early work on the Monterey was dominated basins (Tennyson, 1986; Bachman, 1988).
by Bramlette (1946) who documented the This event is documented by a transgressive
extent of the formation and recognized its sequence (non-marine to shallow~marine to
basic origin. This work still remains as deep-marine) that is present throughout the
the most detailed statewide stratigraphic Coast and Transverse Ranges of California
summary. (Pisciotto and Garrison, 1981; Ingle, 1981).
Following Bramlette's work, surprisingly It is not clear whether the initial
little work was done on the Monterey downdropping was related wholly to transform
Formation until the early 1980's when a tectonics or to some aspect of the trench
flood of publications began to appear. The transform transftion. Regardless, extension
increased interest was due in part to new was the dominant mechanism as evidenced by
analytical methods that were capable of normal faulting and vulcanism which occurred
extracting some of the detailed throughout much of California in Early
paleoclimatic and oceanographic information 'Miocene times (Yeats, 1987).
that some Monterey Formation rocks contain, Clastic sedimentation dominated the early
and in part due to a strong surge in phases of fill in the newly formed basins.
petroleum exploration for Monterey Formation Then approximately 17.5 Ma, Monterey
fractured reservoirs. Much of the new work deposition began abruptly throughout much of
is included in symposium or guidebook California. The major controlling factor
volumes edited by Garrison and Douglas was an abrupt and major reduction in the
(1981), Issacs (1981a), Williams and Graham supply of terrigenous material to reach the
(1982), Isaacs and Garrison (1983), Garrison offshore areas and a high biogenic
and others (1984), and Casey and Barron sedimentation rate (Isaacs, 1985; Graham and
(1986). More recent work with up to date Williams, 1985).
reference lists include: Graham and Williams The sudden reduction in sediment supply
(1985) on the San Joaquin Valley; Barron was apparently caused by tectonic" and
(1986) on dating and paleoceanography; possibly eustatic events (Figure 3). A
T311 :
major tectonic reorganization of the In addition to reduced sediment supply,
borderland, at least in Southern California, high productivity of siliceous organisms in
apparently occurred around the onset of the Pacific region was an important factor
Monterey deposition. Evidence for this promoting Monterey deposition. Worldwide
includes the beginning of rotation of parts siliceous sedimentation apparently switched
of the Transverse Ranges and Mojave area, from low latitude North Atlantic areas to
clear evidence of transform faulting, rapid the North Pacific approximately 17-18 Ma due
downdropping and uplift in coastal areas, to a change in ocean circulation (Keller and
and local volcanism, all occurring Barron, 1983). Furthermore, major polar
approximately 16 to 18 Ma (Tennyson, 1986, cooling began about 15 Ma (Woodruff and
Crowell 1987; Luyendyk and Hornafius, 1987). others, 1981); this probably resulted in
By Middle Miocene times, the offshore area increased ocean circulation and upwelling
was probably composed of a number of small, which enhanced productivity, particularly of
deep (1000-2000 m; 3300-6600 ft) basins diatoms. Average silica accumulation rates
similar to the Southern California during the Miocene are comparable with
borderland today. Outer basins were present rates in highly productive oceanic
protected from sediment influx by trapping areas (Isaacs, 1985). High ocean
of coarse clastics in inner basins. productivity and low terrigenous input
Onshore, considerable sediment was trapped continued into the Late Miocene resulting in
in newly formed interior basins (Figure 1). thick accumulation of hemipelagic calcareous
In addition, a high eustatic sea level
during the Early and Middle Miocene may have
caused flooding of coastal areas, thereby
expanding shelf areas where additional
sediment could be trapped.
MID TOLATE
MIOCENE DEPOSITS
~
MARINE
H~)Y;}J
NONMARINE
SALINASAND
CENTRALCOAST
(0.3)
t
N
o 100 200Km
t
, i !
o 100Miles
N
Figure 2. Location of major onshore Neogene
depocenters (basins) in California. The
o 100 200Km Monterey Formation is present in parts or
I ! !
all of each basin (compare Figure 1).
o 100Miles Numbers indicate cumulative oil production
in billions of barrels; approximately 90%
Figure 1. Present generalized location of was produced from either the Monterey
Late Miocene marine and nonmarine deposits Formation or clastic rocks of Middle Miocene
in California. Modified from Reed (1933) through Pliocene age (Taylor, 1976). The
and Addicott (1968). Monterey Formation is the source of most of
C = Coalinga; B = Bakersfield the oil.
T311: 2
and siliceous deposits throughout much of mountain building throughout most of coastal
California. California and may have also been influenced
Approximately 6 million years ago, a by falling sea level. The Transverse Ranges
sudden influx of terrigenous material and part of the Coast Ranges were initially
signaled the end of Monterey deposition in uplifted at this time, while coastal basins
most areas of California. This influx was continued to subside and fill, setting the
mainly due to the onset of compression and scene for Monterey hydrocarbon generation
and entrapment.
w
z STRATIGRAPHY
w 4
8
::J z M.Y MAINLY The Monterey Formation was originally
4. ~~ CLASTIC laid down as diatomaceous and calcareous
o ROCKS oozes with variable detrital content.
.:E..
Subsequently, most of these sediments were
w
C 6 buried deep enough so that the diatomaceous
oozes were converted, through diagenesis,
zw into the familiar siliceous rock types -
w ,
o
o z ..
i ~
w z •G)
::z:
~ i .5
8 o
w
S "i
.(3
•
S
..
z
~
·z::z: ..C:5:.::J-
~ i ,"i
g
~ •C:
12 1)
i ~ C
w .~..
~
c
i
14
z Figure 4. Diatomaceous sequence, coastal
c
en California.
.5..
/
/
~ 16
N
::J
w w
z a::
ow . a.G;)
o .5
i z .. o
a~Cw:: g~w 18 CMLAAISNTLYIC C·iC&.s...f(!3
ROCKS a
~ c
.::z-: z0
Figure 3. Generalized stratigraphic column
of the Monterey Formation where
uninterrupted by coarse clastics. Climatic
interpretation from Woodruff and others
(1981); sea level curve from Haq and others
(1988); tectonic events referenced in text; Figure 5. Thin-bedded sequence of chert,
ages from Isaacs (1983), Barron (1986), and porcelanite, mudstone, and dolostone;
Dumont (pers. comrn.). siliceous facies, coastal California.
T311: 3
TABLE 1 Common Monterey Formation Rock Types
CHERT: An aphanitic siliceous rock (either opal CT or quartz) with a glassy, vitreous,
or waxy luster; hardness >5; a knife will not scratch it; fractures concoidally or
into angular fragments; color varies in shades of white, black, brown, to nearly
colorless.
PORCELANITE: An aphanitic siliceous rock, (either quartz or opal CT) with a matte luster
resembling unglazed porcelain; commonly laminated; hardness <5; a knife will scratch
it; fractures concoidally or into splintery fragments; light colored when weathered
brown to gray when fresh.
MUDSTONE OR SHALE (SILICEOUS): A fine-grained, massive to crudely laminated rock which
dents on impact, fractures irregularly or along bedding, and shows a waxy impression
when scratched.
DOLOSTONE OR MARL: Dolostone: an aphanitic to sucrosic rock which, when
powdered, fizzes vigorously in dilute HC1; usually gray to brown when fresh-weathers
to a yellow color; scratches easily but very tough, rings when hit with a hammer.
Marl: A fine-grained, light to dark-colored rock that fizzes vigorously in HCl and is
similar in appearance to mudstone or shale as described above.
DIATOMACEOUS ROCK: A massive to laminated soft rock that is noticeably lightweight and
very porous; fresh samples are brownish-weathered samples are chalk white; detritus
rich varieties show a waxy impression when scratched; diatom-rich varieties powder
when scratched.
chert, porcelanite, and siliceous mudstone dominantly clastics in the Puente Formation
(Figures 4 and 5), and calcareous-oozes in the Puente Hills.
became calcareous or dolomitic mudstone or Examples of turbidite sandstone bodies
dolostone (Table 1). At present, within the Monterey Formation include the
diatomaceous rocks remain only in area~ highly oil productive Stevens sandstone in
where burial was minimal, such as along the San Joaquin Valley (Graham and Williams,
basin margins or at the stratigraphic top of 1985) and lower Monterey sandstone in the
the Monterey Formation. western Santa Barbara Channel offshore (Ogle
The thickness of the Monterey Formation and others, 1987).
is highly variable. The thickest deposits The base of the Monterey, where not
are found in basin centers, such as in the obscured by coarse clastics, is generally
southwest part of the San Joaquin basin sharp and dates at approximately 17.5 Ma
where the Monterey is over 3000 m (9800 ft) (Barron, 1986). The upper contact of the
thick. More typically the formation ranges Monterey Formation, where not erosional, is
from 300 to 1000 m (980-3300 ft) thick sharp in some areas and apparently
(Figure 6) with thinner deposits gradational in others. Where the contact is
preferentially located on what were gradational, overlying strata are siliceous
persistent bathymetric highs and basin but are generally more detritus-rich than
margins. underlying Monterey rocks. Age of the
The distinctive, thin-bedded biogenic youngest Monterey Formation rocks is
character of the Monterey Formation is best approximately 6 Ma (Dumont and others, 1986;
developed in areas that were most protected Barron, 1986).
from terrigenous input from land. In In many areas of California the Monterey
general, the purest biogenic sections are Formation can be subdivided into three
found in the Coast Ranges and the western facies: a lower calcareous facies; a middle
Transverse Ranges, areas that were probably phosphatic facies; and an upper siliceous
located furthest from land in Miocene times. facies. Additional subdivisions are
Clastic-dominated sections coeval with recognized locally (e.g., Figure 6).
biogenic Monterey deposits, are typically The CALCAREOUS FACIES consists mainly of
found in easternward outcrops or in areas massive to laminated dolostone, and
that had access to turbidites. calcareous or dolomitic mudstone, siliceous
An example of distal to proximal facies shale, porcelanite, and rare chert.
relationships in southern California is Sections are generally thin-bedded but
shown in Figure 6. In this area, the lithologic variation is wide with so~e
Monterey changes from nearly pure sections composed mainly of carbonate-rich
hemipelagic deposits near Point Conception shale, others dominated by dolostone, and
to subequal clastics in the coeval Modelo still others containing abundant carbonate
Formation in the Santa Monica Mountains - to rich siliceous mudstone and porcelanite.
T311: 4
The PHOSPHATIC FACIES is characterized by types, abundant chert and dolostone, and
dark, laminated, organic-rich, phosphatic, highly variable bed thickness. On the other
calcareous or dolomitic mudstone or marl. extreme are outcrops composed almost
Dolostone nodules or beds are typically entirely of uniformly thin-bedded siliceous
present. The phosphate most commonly occurs mudstone and porcelanite.
in light-colored laminations or in blebs up The three facies are not present
to a few centimeters long. everywhere and are partly age controlled
The SILICEOUS FACIES is characterized by (Bramlette, 1946; Pisciotto and Garrison,
the predominance of laminated siliceous rock 1981). The siliceous facies is the most
types - mainly porcelanite, siliceous distinctive and widespread. Its age spans
mudstone, and chert. In addition, the age range of the Monterey formation
dolostone, and carbonate-rich mudstone are (17.5 to 6 Ma), but it is best developed ln
common in many areas. Two distinct end most areas starting around 12-13 Ma ago.
member outcrop types are recognizable. On The calcareous and phosphatic facies are
one extreme are outcrops that are distinctly best developed in the Central Coast Ranges
heterogeneous with widely varying rock and Western Transverse Ranges; they are
CD @ SANTAMONICAMTNS. @PUENTEHILLS
1
. (Adaptedfrom (Adaptedfrom
PT.ARGUELLOAREA Hoots,1930) Durham&Yerkes,1964)
3,OSOm 6,100m
(10,000')- (20,000')-
':~~.~:~~~:::,i·.~
Sisquoc
Frn.
1070m
-(3~0') (Adaptedfrom @
Issacs,1981) Change
I:::::::::::::::::::::.~...... 1"/..,. OAKCREEK
O~I)
~.I)
(Adaptedfrom
400m Keller,1984)
(1310')..-...
:.::0...0.:..:(:>.:.•.0.:.
Topanga Fm.
Map\\
Are~~
@)
. @
Los 0 •
100Km , Angeles .:•··::·<·I~1;::.;°';:.:.0':; Sespe/Vaqueros '~';.~'~:.-
Monterey Fm.
_-----------A-------_
_ ~:~~::us ~:::.::hatiC ..~:~~::eous
DShale
Figure 6. Comparison of five Miocene sections in Southern California. The Monterey
Formation in the western three sections contain easily recognizable calcareous, phosphatic
and siliceous facies (shaded). Local terminology shown by letters: CS = clayey-sil{ceous
member; UCS = upper calcareous-siliceous member; P = phosphatic member; Les = lower
calcareous-siliceous member. Note that the two e.astern sections (paleo-inboard) are
dominantly sandy but still contain siliceous rocks, especially of Mohnian age. Age control
is from references cited in Figure and M. P. Dumont (pers. comm.).
T311: 5