110°52’30”

22’30” 22’30”

110°52’30”

5

01000mE 5

02 503 5

05 506 5

07 5

09 510 5 111°00’00” 11

31°30’00”

3484000mN

3483

3482

3481

3480

3479

3478

3477

3476

3475

3474

3473

3472

3470

3471

3469

3468

3467

55’

3484

3483

3482

3481

3480

3479

3478

3477

3476

3475

3474

3473

3472

3470

3471000mN

3469

3468

3467000mN

57’30”

5

01 5

02 5

03 5

05 5

07 5

09 5

10 5

11000mE

111°00’00”

55’ 57’30”

22’30” 22’30”

31°30’

27’30”

25’

10

8

12

10 10 12

10

5

10

7

10

12

5

35

4 50

80

70

65

65

70

30

16 40

30

12

17

25

30

50 20

6

5 35

30 60

20

10

35

55

30

20

25

55 15

30

20

35

15

30

4

8

37

10

55

45

65

35

45

35

15

60

45

45

18

70

25

20

15

5

15

15

5

5

5

6

30 35

20

15

15

30

35

35

20

40

35

30

45

35

15

20

20

15

15

25 20

13

20

3

5

15

15

23

5

8

30

25

25

40

20 25

25

20

15

20

30

12

15

12

15

13

15

5

30

48

20

12 10

7

25

28

25

16

10 15

20

15

30

25

12

15

37

15

15

20

15 30

30

25

10

25

25

30

10

12

25

20

10

30

35

10

35

45

27

20

5

15

7

10

10

25

30

15

12

20

25

15

30

18

25

25

30

30

30

43

30

12

20

15

25

30

27

35

32 35

31

25

25

20

85 40

25

25

20

50

60

10

25

30 30 15

10

15 25

40

20

50

30

15 5

5

3

20

25

BUENA

CANYON

Tgg

Qmr

Qm

Qlr1

Qlr1

Tnm Tnm

Qmr Qycr

Qmr

Ql1

Ql1

Qmr Qlr1 Qm

Ql1

Tnm

Ql1 Ql1 Ql2

Ql2

Ql2

Qyr2

Qm

Ql

Qm

Ql2

Qlr1

Ql1

Ql2

Qm

QTa

Qycr

Qyr1 Qyr2

Qy

Qy

Qmr

Qlr1

Qlr1 Qlr1

Qm

Qmr

Qmr

Qlr2

Qyr1

Qm

Qlr

Qlr1

Ql1

Qmr

Qyr2

Qyr1

Qlr1

Qmr

Qmr

Qmr

Qlr

Qmr

Ql1

Qlr

Qm

Tnp

Qmr

Qmr

Tnp Qlr1

Qlr1

Qlr1 Qy Qlr2

Qlr2

Qyr1

Qlr2

Qlr1 Qlr1

Qyr1

Qy

Qy

Tghu

Tnp

Tr

Tghu

Tghu

Tghu

Tghu Qy

Tghm

Tr

Tghm

Tghu

Qm

Ql

Qm

Qm Tnp

Qm

Tnp Ql Ql2

Ql1

Ql2

Ql2

Ql2

Ql1

Ql1

Ql1

Tr

Ql

Qlr1

Qy

Qy Qlr2

Qycr

Qlr2

Qyr1

Qy

Ql2

Ks

Qlr

Ql1

Qy1

Qlr1

Qm Qlr1

Qy

Qyr2

Qyr1

Qlr2

Qlr1

Qm

Qyr1

Qyr1 Qlr2 Qy

Qmr

Qm

Ql1

Qlr1

Tnp

Qlr

Qyr1

Qm

Ql

Qm

Tnm

Qyr2

Qycr

Qyr1

Qlr2

Qlr2

Qlr1

Qy

Ql1

Ql1

Qm

QTa

Tr

Qm

Qlr2

Qlr1

Qlr1

Qlr2

Qyr1

Qy

Qlr1

Qlr

Ql

Qlr2

Qlr2

Qlr1

Qy2

Qlr1

Qlr1

Qo

Qycr

Qy

Qyr2

Qyr2

Qyr2

Qyr1

Qyr1

Qyr2

Qy2

Qy1

Qy1

Qy1

Qlr2

QTa

QTa

Qy1

Ql1

Qy1

Ql1

Qy2

Qyr1

Qy2

Ql2

Qycr

Ql2

Ql2

QTa

QTa

QTa

Qy

Qy

Qy1

Ql1

QTa

Qy

Qm

Qm

Ql2

Ql1

Ql1

Ql1

Ql1

Ql2

Ql2

Ql2

Qyr1

Qyr1

Qy

Qyr1

Qy

Qy

QTa

QTa

QTa

Qy

Qy

Qy

Qm

Qm

Ql1

Ql2

Ql2

Qy

QTa

Qlr2

Qlr2

Qlr

Ql1

Qm

Qm

Ql2 Qy

Qy

Qm

Ql1 Qycr

Qyr2

Qlr1

Qlr1

Ql1

Ql2

Qyr2

Qyr2

Qycr

Qm Qlr1

Tnp

Tnp

Qlr2

Qy

Qyr2

Qlr

Ql1 Ql2

Qy

QTa

Qlr1

Qlr1

Qlr1

Ql2

Qlr2

Qlr2

Qlr2 Qlr2

QTa Qlr2

Qlr1

Qlr2 Qyr1 Qy

Qlr1

Ql2

Ql1

Qlr2

Ql1

Ql2

Qlr2

Qy

Qy

Qy

Qy

Qyr2

Jb

Ks

Ks

Qlr2

Qycr

Qy2

Qyr2

Qy2

Qlr2

Qy1

Qlr2 QTa Qlr1

Qyr1

Qy

Qy

Qy

Qy

Qy

Qlr2

Jb Ks

Ks

Ks

Qyr2

Qyr2

Qyr1

Qyr1

Qlr2

Qycr

Qyr2

Qyr2

Qlr2

Qy

Qy

Ql1

Ql1

Ql1

Qm

Qm

Ql2

Ql2

Ql2

Qlr2

Ql1

Ql1 Qlr1

Qy

Tnm

Ql2

Qyr1

Qlr2

Qlr2

Qlr2

Qyr1

Qyr1

Qyr2

Ql1

Qy2

Qlr2

QTa

QTa Ql2

Qy

Qlr2

Ql1

Ql1

Qm

Qlr2

Qyr1 Qy

Qlr2

Jb

Qy1 Qy1

Ql1

Ql2

Ql

Qy2

Qy2

Ql1

Qy2 Qlr2

Tnm

Qy2

Ql

Ql2

Qm

Ql1

Ql2

QTa

QTa Qm

QTa

QTa

Qm

Ql1

QTa

Ql2

Ql2

Qy1

Ql1

Ql2

Qy1

Ql

Qlr2

Qlr2 Ql1

Qy

Qy

Qlr2

Qyr2

Qyr2

Qyr1

Qyr1

Qyr2

Qyr2

Qycr Qyr2

Qyr1

QTa

Qy

Qy

Qm

Tnm

Qlr2

Qlr2

Jbm

Jbm

Jbm

Qy

Tnp

Tnpd

Tnp

Tnm

Tnp

Tnn

Tnn

Tnn

Tnm

Tnn

Tnn

Qy

Qy

Tnp

Kd

Qy

QTa

Tnm

QTa

Tnm Tnn

Tnn

Ql

Qy

QTa

Tnm

Tnm

Tnp

Tnm

Tnp

Qy

Qy

Tnp

Qlr

Ql

Ql

QTa

QTa

QTa

Qy

Qy QTa

QTa

Qy

Ql

Ql

Ql

Qy2

Qycr

Qy

Qm

Qm

Qm

Ql2

Ql2

Ql2 Ql2

Qy2

Ql2

Ql1

Qy1

Qy1

Ql

Ql2

Ql2

Tghu

Tnp

Tghu Tnp

Qy1

Qyr1

Tnm

Qlr2

Tnp

Qy1

Jb

Qlr2

12SCB05

12SCB04

12SCB03

11SCB02

11SCB03

11SCB08

11SCB09

11SCB07

12SCB01

Tghu

Tghm

QTa

Qy

Qmr

Tnp

Qy1

Ql2

Qyr1

27’30”

Tnmb

Tnmb

11SCB01

Qy

Qy

Qyr2

Qlr2

Tr

RIO

FAULT

RICO

FAULT CAYETANO SAN FAULT

AVENUE

GRAND

FAULT

GOLD

HILL

FAULT

MOUNT

BENEDICT

FAULT

FAULT

CANYON

PROTO

YERBA

FAULT

PROTO

CANYON

GRAND

AVENUE

FAULT

MOUNT

FAULT

BENEDICT

FAULT

GOLD

HILL

FAULT

RICO

RIO

BUENA

CANYON

FAULT

YERBA

MOUNT

FAULT

BENEDICT

LIST OF MAP UNITS

[Colors on the map may appear darker due to the hillshade transparancy]

ALLUVIAL AND BASIN-FILL DEPOSITS

Active river-channel deposits (latest Holocene)

Young river floodplain and terrace deposits (late Holocene)

Young river terrace deposits (Holocene)

Young alluvial deposits, undivided (Holocene)

Younger of the young alluvial deposits (late Holocene)

Older of the young alluvial deposits (Holocene)

Young intermediate river-terrace deposits, undivided (late Pleistocene)

Younger of the young intermediate river-terrace deposits (late Pleistocene)

Older of the young intermediate river-terrace deposits (late Pleistocene)

Young intermediate alluvial deposits, undivided (late Pleistocene)

Younger of the young intermediate alluvial deposits (late Pleistocene)

Older of the young intermediate alluvial deposits (late Pleistocene)

Older intermediate river-terrace deposits (middle Pleistocene)

Older intermediate alluvial deposits (middle Pleistocene)

Old alluvial deposits (early Pleistocene)

Alluvial basin fill (early Pleistocene? to Miocene)

Alluvium and basin-fill deposits, undivided (Holocene to Miocene)—On cross sections only

Nogales Formation (Miocene)

Mariposa member—Stipple pattern indicates basalt flows

Nogales Wash member

Proto Canyon member—Red area indicates location of dacite dikes

BEDROCK UNITS

Grosvenor Hills Volcanics (Oligocene)

Upper rhyodacite member

Rhyodacite and rhyolite intrusive rocks

Middle rhyolite member

Tertiary volcanic rocks, undivided (Oligocene)—On cross sections only

Gringo Gulch Volcanics (Paleocene)

Diorite (Upper Cretaceous)

Salero Formation (Upper Cretaceous)

Quartz Monzonite of Mount Benedict (Jurassic)

Biotite-hornblende quartz monzonite

Quartz monzonite

Cretaceous and Jurassic rocks, undivided—On cross sections only

EXPLANATION

Contact

Normal fault—Long-dashed where approximately located, short dashed where geophysically 

inferred, dotted where concealed; small red arrow shows direction and angle of dip; ball 

and bar on apparent downthrown side

Anticline—Long-dashed where location approximate

Syncline—Long-dashed where location approximate

Horizontal bedding

Overturned bedding—Showing strike and dip

Inclined bedding—Showing strike and dip

Inclined flow layering—Showing strike and dip

Vertical flow layering—Showing strike

Geochronological sample—Showing sample locations with sample number

15

20

65

80

Tr

Tghm

Tghu

Qy1

Qy2

Qy

Qyr1

Qyr2

Qycr

Ql1

Ql2

Ql

Qlr1

Qlr2

Qlr

QTu

QTa

Qo

Qm

Qmr

Tnn

Tnp

Ks

Kd

Tgg

Tv

KJu

Jbm

Jb

Tnm

11SCB01

Tnmb

Tnpd

CORRELATION OF MAP UNITS

Disconformity

Unconformity

Unconformity

Unconformity

Unconformity

Unconformity

Unconformity

Holocene

late Pleistocene

middle Pleistocene

early Pleistocene

Pliocene

Miocene

Oligocene

Paleocene

QUATERNARY

TERTIARY

UPPER CRETACEOUS

JURASSIC

Tnn

Tghu

Tghm Tr

Tv

QTu

Tgg

Kd

Ks

KJu

Jb

Jbm

Qy2

Qy1

Ql

Qm

QTa

Qo

Ql2

Ql1

Tnp

ALLUVIAL AND BASIN-FILL DEPOSITS

BEDROCK UNITS

Tnm

Qyr2

Qyr1

Qlr2

Qlr1

Qycr

Qlr

Qmr

Qy

NOGALES FORMATION

GROSVENOR HILLS VOLCANICS

QUARTZ MONZONITE

OF MOUNT BENEDICT

Tnmb

Tnpd

DIVISION OF QUATERNARY TIME USED IN THIS REPORT1

Holocene

1

Ages for time divisions are from Cohen and others (2013; updated). Ma, million years; ka, thousand years. 

Quaternary

Period Epoch

0–11.7 ka

late 11.7–126 ka

middle 126–781 ka

early 781 ka–2.58 Ma

Age

Pleistocene

CONVERSION FACTORS

Multiply By To obtain

meter (m) foot (ft) 3.281

millimeter (mm) 0.03937 inch (in.)

kilometer (km) 0.6214 mile (mi)

centimeter (cm) inch (in.) 0.3937

Figure 1. Location map of Rio Rico and Nogales (Arizona) 7.5 ́ quadrangles, showing major 

physiographic, geologic, and hydrologic features in the map area. Black squares are town locations and 

black ball and bar symbols indicate the downthrown side of normal faults. Fault dashing has been simplified 

from main map.

111°

31°30’

31°22’30”

110°52’30”

NOGALES

RIO RICO

Rio Rico

UNITED STATES

MEXICO

Mount Benedict

19

Sonoita Creek

Nogales Wash

RIO RICO FAULT

SAN CAYETANO FAULT

GOLD HILL FAULT

GRAND AVENUE FAULT

PROTO CA

NYON FAULT

YERBA BUENA CANYON FAULT

MOUNT BENEDICT FAULT

Rio Rico

Basin

Guevavi

Canyon

Grosvenor Hills

Fresno Canyon

San Cayetano

Mts.

Mount

Potrero Canyon

Ephraim

Nogales

M

ARIPOSA ROAD

Canyon

Yerba Buena Canyon

GRAND

AVENUE

Mariposa Canyon

Santa Cruz River

0 0.5 1

0 0.5 1

1.5 MILES

1.5 KILOMETERS Late Miocene−Holocene

 alluvium

Miocene Nogales Formation

Bedrock

EXPLANATION

19

82 Proto

 block

 Canyon

Shaded-relief base from U.S. Geological Survey 

National Elevation Dataset (NED) 

(accessed in 2015 at http://ned.usgs.gov/), 

10-meter resolution elevation data

Shaded-relief base from U.S. Geological Survey 

National Elevation Dataset (NED) 

(accessed in 2015 at http://ned.usgs.gov/), 

30-meter resolution elevation data

horst

Benedict

Tubac

Patagonia

Nogales

Kino Springs

NOGALES KINO SPRINGS

PEÑA BLANCA LAKE RIO RICO CUMERO CANYON

TUBAC

AMADO

Atascosa 

Mountains

 Tumacacori Mountains

Pajarito Mountains

Agua Fria Canyon

Peña Blanca

Canyon

Josephine Canyon

Grosvenor

Hills

Sierrita Mountains

Sonoita

Creek

31°45’

31°30’

111° 110°45’

Patagonia

Mountains

Santa

Cruz

River

Nogales Wash

Amado

Tucson

Basin

Santa Rita Mountains

San Cayetano

Mts.

Cottonwood Canyon

Santa Cruz River

PIMA COUNTY

SANTA CRUZ COUNTY

UNITED STATES

MEXICO

Sopori Wash

19

19

289

82

01234

01234

5 MILES

5 KILOMETERS

111° 110°30’

31°15’

31°45’

31°30’

Patagonia

Rio Rico

Nogales

Tubac

Amado

SCR

USA

MEXICO

0

0

5

5

10 MI

10 KM

Figure 2. Location map of upper Santa Cruz basin area, showing major physiographic, geologic, and hydrologic features in the region. 

Black squares are town locations. Inset map in upper right shows location of upper Santa Cruz River basin with boundary in gray, Santa 

Cruz River (SCR) in blue, and boundaries of Rio Rico and Nogales quadrangles in red.

Rio Rico

SONORA 

ARIZONA

Late Miocene−Holocene

 alluvium

Miocene Nogales Formation

Bedrock

EXPLANATION

Walker Canyon

Mariposa member—Moderately to weakly consolidated calcareous, volcaniclastic sandstone and conglomerate, 

siltstone, claystone, basalt flows dated at 11.67 Ma; 300–350 m thick

Alluvium—Poorly to moderately bedded, unconsolidated to weakly consolidated, poorly sorted, interstratified sandy 

gravel and gravelly sand, deposited in major and tributary drainages and in piedmont alluvial fans; generally 3 to 4 m 

thick

Basin-fill deposits—Moderately to poorly bedded, weakly consolidated, interstratified gravelly sand to sandy gravel; 

generally ≤100 m thick

Nogales Wash member—Moderately consolidated volcaniclastic sandstone and conglomerate, abundant pumice 

fragments, pervasively fractured; basal 20–30 m of member forms massive cliffs; 50–150 m thick

Proto Canyon member—Moderately to weakly consolidated volcaniclastic conglomerate and sandstone, arkosic 

sandy and clayey conglomerate, and gravelly claystone; includes basal debris-flow conglomerate which grades 

upward into arkose conglomerate and sandstone; maximum thickness about 450 m

Upper rhyodacite member—Rhyodacite and rhyolite tuff, agglomerate, flow breccia, and latite; rhyolite tuff samples 

dated at 24.8–23.5 Ma, and another at 26.9–26.3 Ma; 75 m thick

Middle rhyolite member–Vitric-lithic tuff, rhyolite lava, tuffaceous sandstone and conglomerate; rhyodacite plugs 

dated at 27.8 Ma; 100 m thick

Andesite lava and flow breccia, latitic to rhyolitic tuff and lava, tuffaceous conglomerate; 10–20 m thick

Diorite stock—Augite, hypersthene, and biotite, altered

Arkosic conglomerate and conglomeratic sandstone, argillite, and conglomeratic quartzite; 50–400 m thick

Porphyritic biotite-hornblende quartz monzonite; lamprophyre, microdiorite, or diabase dikes

QUATERNARY TERTIARY

Miocene

JURASSIC CRETACEOUS

Middle

Quartz 

Monzonite of

Mount Benedict

Upper Paleocene Oligocene Pleistocene Pliocene

Quaternary alluvium Basin-fill deposits

Nogales Formation Salero

Formation Diorite

GringoGulchVolcanics

GrosvenorHills Volcanics Proto Canyon member Nogales Wash member Mariposa member

Holocene

Figure 3. Stratigraphic chart of sediments and rocks in map area. Unconformities and disconformities are indicated by the wavy line.

Period Epoch Units Description

Geologic map of the Rio Rico and Nogales 7.5’ quadrangles, Santa Cruz County, Arizona

By

William R. Page, Christopher M. Menges, Floyd Gray, Margaret E. Berry, Mark W. Bultman, Michael A. Cosca, and D. Paco VanSistine 

2016

Publishing support provided by: 

Denver Publishing Service Center

Edit and digital layout by J.A. Herrick

Manuscript approved for publication March 4, 2016

To learn about the USGS and its information products visit

http://www.usgs.gov/

1-888-ASK-USGS

Any use of trade, firm, or product names is for descriptive purposes only and does not 

imply endorsement by the U.S. Government.

Although this information product, for the most part, is in the public domain, it also 

contains copyrighted materials as noted in the text. Permission to reproduce 

copyrighted items must be secured from the copyright owner.

This database, identified as SIM 3354, has been approved for release and publication by 

the U.S. Geological Survey (USGS). Although this database has been subjected to 

rigorous review and is substantially complete, the USGS reserves the right to revise the 

data pursuant to further analysis and review. Furthermore, it is released on condition 

that neither the USGS nor the U.S. Government may be held liable for any damages 

resulting from its authorized or unauthorized use.

 

Although these data have been processed successfully on a computer system at the 

U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the 

display or utility of the data on any other system or for general or scientific purposes, nor 

shall the act of distribution constitute any such warranty. The USGS or the U.S. 

Government shall not be held liable for improper or incorrect use of the data described 

and/or contained herein.

ISSN 2329-132X (online)

http://dx.doi.org/10.3133/sim3354

Suggested citation: Page, W.R., Menges, C.M., Gray, Floyd, Berry, M.E., Bultman, M.W., Cosca, M.A., and VanSistine, 

D.P., 2016, Geologic map of the Rio Rico and Nogales 7.5’ quadrangles, Santa Cruz County, Arizona: U.S. Geological 

Survey Scientific Investigations Map 3354, 32 p. pamphlet, 2 sheets, scale 1:24,000, http://dx.doi.org/10.3133/sim3354.

Mapping of the Miocene Nogales Formation was completed from 2011 to 2014 by William 

R. Page, Christopher M. Menges, Floyd Gray, and Margaret E. Berry. Late Miocene to 

Holocene alluvial and basin-fill deposits were mapped from 2011 to 2014 by Christopher 

M. Menges and Margaret E. Berry. Mesozoic bedrock units and the Oligocene Grosvenor 

Hills Volcanics were compiled from existing published geologic maps in the area, 

including those of Simons (1974) and Drewes (1972, 1980). Mark W. Bultman completed 

geophysical modeling, which defined the geometry of concealed faults and basin and 

bedrock geology and constrained the subsurface geology shown in the cross sections. 

Michael A. Cosca completed 40Ar/39Ar geochronology studies resulting in stratigraphic 

revision of the Oligocene Grosvenor Hills Volcanics and Miocene Nogales Formation. D. 

Paco VanSistine created cross section profiles and assisted authors in creating, editing, 

and finalizing the geologic map database and metadata. T.R. Brandt produced the digital 

topographic base map.

U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Map 3354

Sheet 1 of 2

Pamphlet accompanies map

Base from U.S. Geological Survey 1:24,000-scale maps: Rio Rico, Arizona, 1996; Nogales, 

Arizona–Sonora, 2004 and revised by the U.S. Forest Service January 18, 2013

North American Datum 83 (NAD 83)

Universal Transverse Mercator, zone 12

Shaded-relief base from U.S. Geological Survey National Elevation Dataset (NED) 

(accessed in 2015 at http://ned.usgs.gov/), 10-meter resolution elevation data

UTM grid in Nogales quadrangle created in 2016 from USGS sources

SCALE 1: 24 000

1 1/ 2 0 1 MILE

1000 1000 0 2000 3000 4000 5000 6000 7000 FEET

1 0 .5 1 KILOMETER

APPROXIMATE MEAN

DECLINATION, 2015

10 ̊

TRUE NORTH

MAGNETIC NORTH

CONTOUR INTERVAL OF 40 FEET

SUPPLEMENTARY CONTOUR INTERVAL OF 20 FEET

NATIONAL GEODETIC VERTICAL DATUM OF 1929

ARIZONA

QUADRANGLE LOCATION

UNITED STATES OF AMERICA

ESTADOS UNIDOS MEXICANOS

F

E

D

C

B

A

A'

B'

C'

D'

E'

F'