73

4

6783

74

60

54

58

35

30

68

35

44

53

35

59

34

46

29

28

62

57

54

64

34

34

48

29

29

48

27

32

49

22

77

55

40

34

40

45

60

68

58

4062

40

43

45

60

4037

40

70

70

45

25

40

75

60

31

60 55

65

44

63

87

20

66

36

5642

43

35

57

50

56

50

36

37

40

45

42

35

41

38

44

57

50

47

55

36

2320

1721

57

50

25

20

36

2828 24

4770

24

39

22

31

19 18

4026

82

30

32

48

40

26

25

37

35

58

60

32

35

55

27

25

35

32

45

40

40

30

75

35

37

35

40

30

30

38

50

40

25

25

51

38

32

27

10

26

41

3130

25

70

60

40

40

44

71

60

84

40

36

44

30

40

48

44

43

55

37

30

35

30

2327 20

27

45

35

55

46

6023

45

4747

40 40

45

50

5150

61

30

36

40

47

4659 65

55

35

60

30

3637

65

55

4335

43

55

48

51

28

38

36

5470

30

41

3063

55

28

25

38

43

3545

3730

59

27

KJgv

Qf

Kv

Kg

Ks

Ks

KJgv

Qhl

Qhf

Kf

Qhf

Qpf

Kg

Ky

Kg

Qhf

Ks

Kg

Qhf

Qpf

Qhf

KJgv

Kg

Qpf

Qha

Kg

Qhff

Qhf

Kf

Qpf

KJgv

Qa

KJgv

Qa

Qhf

Ks

Qhf

Qa

Qpf

KJgv

Qhf

Qhff

Ks

Qhf

Qhf

Qa

Qa

KJss

Qhf

Qls

Td

Qhf

Qa

Qha

KJgv

KJgv

KJgv

Qhff

Tpth

Qhl

Qa

Qhc

Qpf

Qa

KJss

Qa

KJss

KJgv

KJss

Teu

KJgv

Qhl

Kfo

Qha

Kfo

Kf

KJss

Qhff

Kg

Qhf

KJss

Kg

Qpf

Kush

Kf

Qhl

Qhl

Kf

af

Qpf

Tmz

Qhf

Qhl

Qhc

KJss

Tsvm

Qls

Qa

Qhb

Qhc

af

Qls

Qls

Qtv

Qha

Qhc

Qls

Ky

Qhl

Qha

Qhc

af

af

Qls

Qtv

Qls

Qls

Qls

Kv

Kush

Qha

Qoa

Qpf

Qls

Qhff

Qls

Qls

Qha

Kg

Qls

KJgv

af

Qhb

KJgv

Qls

Qa

Tpus

Qhc

Td

Qls

af

Kf

Kush

Qls

Qhl

Qha

Qls

Qoa

af

Qls

Qls

Ks

af

Qhfaf

Qls

Qha

Qhb

Kfo

Qa

Qls

Qt

Qhc

Qls

Kfo

Qhf

Qls

Qpf

Ks

Qhf

Qpf

Qa

af

Qtv

Qtv

Qtv

Qhf

Qhf

Tpth

Qha

Qha

Qhf

KJgv

Qa

Qa

Qhf

af

Tpu

KJgv

Tsvm

Kg

Qhl

Qha

af

Kg

Ks

Qa

Qhl

Kush

KJgv

af

Qhc

Qhc

Qhc

Kush

KJss

Qhf

Qhc

Kg

Qhc

Qhf

Qtv

Qha

Qhf

Qhf

Qha

KJgv

Qhf

Qhl

Qhl

Qpf

af

Kg

Ks

Ks

Ky

Kv

Kv

Ky

Kg

KJgv

KJgv

KJgv

KJgv

Qhc

TpuTpus

Qhly

Copyright © 2006 by the California Department of Conservation

California Geological Survey. All rights reserved. No part of

this publication may be reproduced without written consent of the

California Geological Survey.

"The Department of Conservation makes no warranties as to the

suitability of this product for any given purpose."

122°00'00"

38°15'00" 38°15'00"

122°07'30"

122°07'30"

38°22'30"

122°00'00"38°22'30"

GEOLOGIC MAP OF THE

FAIRFIELD NORTH 7.5' QUADRANGLE

SOLANO AND NAPA COUNTIES, CALIFORNIA: A DIGITAL DATABASE

VERSION 1.0

By

Mark O. Wiegers1, Janet M. Sowers2, and Robert C. Witter2

Digital Database

by:

Carlos I. Gutierrez3

2006

CALIFORNIA GEOLOGICAL SURVEY

JOHN G. PARRISH, PhD., STATE GEOLOGIST

STATE OF CALIFORNIA - ARNOLD SCHWARZENEGGER, GOVERNOR

THE RESOURCES AGENCY - MICHAEL CHRISMAN, SECRETARY FOR RESOURCES

DEPARTMENT OF CONSERVATION - BRIDGETT LUTHER, DIRECTOR

1. California Geological Survey, 135 Ridgway Avenue, Santa Rosa, CA 95401

2. William Lettis & Associates, Inc., 1777 Botello Drive, Suite 262, Walnut Creek, CA 94596

3. California Geological Survey 801 K Street, MS 12-31, Sacramento, CA 95814

This geologic map was funded in part by the

U.S. Geological Survey National Cooperative

Geologic Mapping Program, STATEMAP

Award no. 05HQAG0080

Topographic base from U.S. Geological Survey

Fairfield North 7.5-minute Quadrangle, 1980

UTM projection, North American Datum 1927

Strike and dip of bedding.25

Landslide - Arrows indicate principal direction of movement.

Symbol Explanation

Contact between map units - Solid where accurately located, dashed where

approximately located, dotted where concealed.

Fault - Solid where accurately located, dashed where approximately located,dotted where concealed.

Axis of syncline - Solid where accurately located, dotted where concealed.

Anticline - Solid where accurately located, dashed where approximately located;

dotted where concealed.

25Strike and dip of overturned bedding

Strike and dip of vertical bedding

Fox, K.F. Jr., 1983, Tectonic setting of late Miocene, Pliocene and Pleistocene rocks in part of the Coast Range North of San

Francisco, California: U.S. Geological Survey Professional Paper 1239, 92 p.

Hart, E.H., 1978, Limestone, dolomite, and shell resources of the Coast Ranges Province, California: California Division of

Mines and Geology Bulletin 197, 103 p.

Graymer, R.W., Jones, D.L., and Brabb, E.E., 2002, Geologic map and map database of northeastern San Francisco Bay Region,

Most of Solano County and parts of Napa, Marin, Contra Costa, San Joaquin, Sacramento, Yolo, and Sonoma counties:

U.S. Geological Survey Miscellaneous Field Studies Map MF-2403, scale 1:62,500.

Lachenbruch, M.C. 1962, Geology of the west side of the Sacramento Valley: California Division of Mines and Geology

Bulletin 181, p. 53 - 86.

Sims, J.D., Fox, K.F., Bartow, J.A., and Helley, E.J., 1973, Preliminary geologic map of Solano and parts of Napa, Contra Costa,

Marin, and Yolo counties, California: U.S. Geological Survey Miscellaneous Field Studies Map MF-484, scale 1:62,500.

Weaver, C.E., 1949, Geology of the Coast Range immediately north of the San Francisco Bay Region, California: Geological

Society of America Memoir 35, 242 p., plates 6, 10, scale 1:62,500.

Witter, R.C., Knudsen, K.L., Sowers, J.M., Wentworth, C.M., Koehler, R.D. and Randolph, C.E., 2006, Maps of Quaternary

deposits and liquefaction susceptibility in the central San Francisco Bay Region, California: U.S. Geological Survey Open-File

Report 2006-1037.

References

UTM GRID AND 1980 MAGNETIC NORTHDECLINATION AT CENTER OF SHEET

0°35'10 MILS

GNMN

161/2°293 MILS

0

0

0

1

1

1.5

.5 2

2

2Thousand Feet

Kilometers

Miles

Contour Interval 20 Feet

Dotted Lines Represent 5 Foot Contours

National Geodetic Vertical Datum of 1929

Scale 1:24,000

5Kilometers

5Miles

Napa

Mapping completed under

STATEMAP

FY 2001-02

FY 2002-03

FY 2003-04

FY 2004-05

FY 2005-06

CGS CD 2002-07

FY 1997-98

12121

12116

80

80

680

San Pablo

Bay780

37

128

Sonom

a

Novato

Mt. G

eorge

Napa

Petalum

a

Petalum

aRiver

Cuttings

Wharf

Glen E

llen

Cotati

Two R

ock

Sears P

oint

Yountville

Rutherford

FairfieldSouth

Cordelia

Capell Valley

FairfieldNorth

QUATERNARY

Pliocene

Holocene

Pleistocene

Miocene

TERTIARY

CENOZOIC

Unit Correlation

Qha

Qhly

Qoa

Qls

Qt

Qht Qha

QfQa

Qof

MESOZOIC

CRETACEOUS

JURASSIC

Qpf

Qhf

Tsvm

af Qhc

Qhff Qhl

Qtv

Paleocene

Td

TeuEocene

Tpu

Tmz

Tpus

KJgv

KJss

Kush

Kfo

Kg

Kf

Ks

Ky

Kv

Landslide deposits (Holocene and Pleistocene) - Includes debris flows and block slides. Qls

Alluvium, undivided (latest Pleistocene to Holocene) - Flat, relatively undissected fan, terrace, and basin deposits.Qa

Qoa Alluvial deposits, undivided (early to late Pleistocene) - Alluvial fan, stream terrace, basin, and channel deposits.

Topography is gently rolling with little or no original alluvial surfaces preserved; moderately to deeply

dissected.

QhaAlluvium, undivided (Holocene) - Alluvium deposited on fans, terraces, or in basins; composed of sand, gravel, silt,

and clay that are poorly sorted.

QhcModern stream channel deposits (Holocene <150 years) - Deposits in active, natural stream channels; consists

of loose alluvial sand, gravel, and silt.

QhfAlluvial fan deposits (Holocene) - Alluvial fan sediment deposited by streams emanating from mountain drainages

onto alluvial valleys; composed of moderately to poorly sorted sand, gravel, silt and clay.

Unit Explanation

(See Witter and others (2006), for more information on

Quaternary units).

Qf Alluvial fan deposits (latest Pleistocene <~30,000 years to Holocene) - Sand, gravel, silt and clay mapped on

gently sloping, fan-shaped, relatively undissected alluvial surfaces.

QhtStream terrace deposits (Holocene <10,000 years) - Stream terraces deposited as point bar and overbank

deposits along Lichau Creek; composed of moderately to well-sorted and bedded sand, gravel, silt, and

minor clay.

QofAlluvial fan deposits (early to late Pleistocene) - Alluvial fan sediment composed of weakly cemented conglomerate

and sandstone. Clasts are volcanic, subrounded, and range up to 8 inches in diameter. Topography is

moderately rolling with little or no original alluvial surfaces preserved; deeply dissected.

TsvmSonoma Volcanics, mafic flows and breccias (Miocene) - Basalt, basaltic andesite and andesite flows and breccias,

interbedded with volcanic agglomerate and tuff.

QhlFan levee deposits (Holocene) - Fan sediments deposited as long, low ridges oriented down fan. The

deposits contain coarser material than the adjoining areas.

af Artificial fill (Holocene, historic) - May be engineered and/or non-engineered.

QpfAlluvial fan deposits (late Pleistocene) - Late Pleistocene age is indicated by greater dissection than is present on

Holocene fans; composed of moderately to poorly sorted and bedded gravel, sand, silt, and clay.

QtStream terrace deposits (late Pleistocene to Holocene) - Deposited in point bar and overbank settings where

deposits might be of late Pleistocene or Holocene age; composed of unconsolidated, poorly sorted, clayey

sand and sandy clay with gravel.

Qhly

Qhff

Qhb

Alluvial fan levee deposits (Holocene < 1,000 years) - Sand and silt overbank deposits along channel

margins of young alluvial fans.

Alluvial fan deposits, fine facies (Holocene) - Predominantly clay and silt with interbedded coarser alluvium

deposited on distal portions of alluvial fans and valley floors.

Basin deposits (Holocene) - Fine-grained clay-rich alluvium with horizontal stratification. May contain peat and

interbedded coarser alluvium.

QtvTravertine (Holocene and Pleistocene) - Surficial deposits of fine- to coarse-grained travertine, microcrystalline

onyx and related calcareous materials deposited by saline springs associated with faults. Spring waters

are rich in 18O indicating a deep basinal rather than a meteoric source (Criss, written communication,

1998). Travertine deposits are underlain by brecciated sandstone and conglomerate cemented by

travertine. Travertine in the Fairfield North quadrangle was mined for cement at Cement Hill and for

decorative material at both Cement Hill and Tolenas Springs (Hart, 1978).

Teu

Tpu

Tpus

Tmz

Kush

Td Domengine Sandstone (Eocene) - White quartz-rich sandstone with interbedded sandstone and shale.

Unnamed mudstone, sandstone, siltstone (Eocene) - Foram-bearing mudstone, sandstone and siltstone.

Contains Early Eocene nannofossils (Ristau, unpublished data, 2006).

Unnamed sandstone and shale (Paleocene) - Sandstone, siltstone and foram-bearing mudstone and shale. In

the Cement Hill area, this unit contains Paleocene nannofossils and a glauconite-rich basal zone in

contact with Upper Cretaceous rocks (Ristau, unpublished data, 2006).

Basal sandstone member - Mica- and quartz-rich sandstone, cross-bedded in places. Present in the

Vaca Valley area.

Martinez Formation (Paleocene) - In the Cement Hill area, this unit contains a shell-rich sandstone bed with

Paleocene Turritella fossils (Ristau, unpublished data, 2006)(Powell, written communication, 2002).

Unnamed sandstone and shale (Late Cretaceous) - Sandstone, siliceous shale and mudstone.

Kfo

Kg

Kf

Ks

Ky

Kv

Forbes Formation (Late Cretaceous) - Thick beds of fine- to coarse-grained sandstone with shell fragments

grading upward into interbedded siltstone and shale.

Guinda Formation (Late Cretaceous) - Thick-bedded to massive sandstone grading upward into siltstone

and shale.

Funks Formation (Late Cretaceous) - Siltstone and mudstone with thin beds of sandstone.

Sites Formation (Late Cretaceous) - Thick-bedded, laminated fine- to medium-grained sandstone with

moderately thick beds of siltstone.

Yolo Formation (Late Cretaceous) - Moderately thick-bedded, fine- to coarse-grained sandstone mudstone and

micaceous siltstone.

Venado Formation ( Late Cretaceous) - Massive to thick-bedded, shale-chip bearing sandstone with minor

siltstone. North of the Fairfield quadrangle at Monticello Dam, this unit includes a basal submarine

slump deposit consisting of megabreccia with angular blocks of sandstone and siltstone in conglomeratic

mudstone matrix.

KJgvSandstone and shale (Early Cretaceous and Late Jurassic) - Mostly thin-bedded sandstone with interbedded

siltstone, shale and mudstone. Contains discontinuous beds of conglomerate.

KJss Ridge-forming sandstone beds.

Great Valley Sequence

Preliminary Geologic Map available from:

http://www.conservation.ca.gov/cgs/rghm/rgm/preliminary_geologic_maps.htm

Revised: 09/27/2006