az USGS U.S. DEPARTMENT OF THE INTERIOR
science forachangingworld U.S. GEOLOGICAL SURVEY

SURFICIAL DEPOSITS

CORRELATION OF MAP UNITS

VOLCANIC ROCKS AND DEPOSITS OF THE CASCADE RANGE AND NEWBERRY VOLCANO

VENT DEPOSITS AND INTRUSIONS

Young volcanic rocks of Santiam
and McKenzie Passes

Basalt of the Cascade Range
and Newberry volcano

Basaltic andesite of the Cascade Range

Andesite of the Cascade Range

Dacite, rhyodacite, and rhyolite of the Cascade Range

Pyroclastic flow and fall deposits

Qal Qe Qls at

Rock Mesa-Devils Hill ash bed

Tdtd

Tat

Tdtp
Tdtm

Tat

~ Tdreb
6.1420.06

a

6.7420.20 » Tdrsf

28.341. (Powell Buttes)
28.8240.23 (Gray Butte)

0.010 re] Hf feceeefenee
Qbam
Qgc [eee] [atess, Qbah || Qbamx|| Qbasm
Qbn,
Qgs Qos Qbse [bess] Qbasx
Qbatm
(1-5)
[Be [em] om a
veposs ot ovesng ae Rees [ aba |
glaciations in Cascade a atone L554
ange probly resent aot | Pabe% a
but not recognized SASS
— Age unknown relative ~
Qs Rabe] f tw other voleanie or [aban | |:Qbat!!
Qgj Qoj ROG glacial events
ap |{ abwi |{ abg ]{ abn |] abn ba |[ ababp || bat [[abaw | Qbasp
Y,
Som os
Qbn younger than
Tumalo Tuff (Qtt) in
area near Bend
Age uncertain relative
Qsd to TumaloTuff (tt) [avape|
but may predate it
Qbpp
[at | 1.190.08
Qoba
1.4340.33
1.6 © Joe see
QTs 2
VOLCANIC AND SEDIMENTARY ROCKS IN THE DESCHUTES BASIN
—2—
Tbal |} Thas .| 2,910.2
L—
[Tee
Thdr [tm | 3.5610.30
Deschutes Formation
Tds || Tdb
[ Tabe | 5,7740.07
Unconformity to disconformity
John Day Formation
23.7 ve
[mw | 27.6240.63
Tits
29.5740.17
32.4920.30 |. Tis
36.6

METERS
3000

Cascade Range crest

SAND MOUNTAIN VOLCANIC FIELD Santiam Pass

SP 77-24
drill hole
bsp

Green Ridge

2000

Qb Qal

Metolius River

Qgs

es

BEND IN

Squaw Back)
(1408

1000

Middle Miocene strata

SEA LEVEL Miigebruptly eastward

Upper Miocene and Pliocene lava flows, chiefly basaltic andesite

1000

Western Cascades strata
of John Day age

Middle Miocene volcanic and volcaniclastic strata
2000

SECTION

Ridge
Im)

Tdb

Deschutes River

Tdblid
Tdbid Tdtm

Tds

John Day Formation to east
interfingers with calc-alkaline
volcanic strata of Cascade Range to west

(not shown on map)
Mazama ash bed
Qass,
on a
= 1 Qdss,
Qass | 093 |Z, Qah-| >a
[een 40-011 9 840.02
Qr
Qd Qrd
Qrdt
0.213
+£0.09
).460+0.030
Qoad

Tde

A"
2 (8 S
2/5 z
ala =

z
k=)

Juniper|Butte =

Tir

Tith

Subsurface extent uncertain
for stratigraphic members
of John Day Formation

30.820.5

pre-John|Day strata

FAULT ZONE

t

‘@ CYRUS SPRINGS

Approximate age.
(Ma)
[Nonlinear time scale
from Palmer, 1983]

#6 0,010 —feeeeeee

Beginning of
South Sister volcano

Approximate age of
Jack Creek glaciation ~ |

Approximate age
of Tumalo Tuff —]

Approximate age of
Desert Spring Tuff —}

0.78

10 4

GEOLOGIC INVESTIGATIONS SERIES I-2683
SHEET 2 of 2

Pamphlet accompanies map

Polarity
Age (Ma)
[Shaded (normal) and white (reversed)
polarity shown for major subchrons
through end of Gauss time]

> ~ >)
Holocene
Brunhes Normal-
Polarity Chron
QUATERNARY
Pleistocene
0.78 =
Matuyama Reversed-
, $32 ...{.. Polarity, Chron, 2
1.98
2.60
Gauss Normal-
3.05 F Polarity Chron
Pliocene
3.55
Pre-Gauss chrons
Miocene
TERTIARY
Oligocene
Eocene
J
AlTM
5 METERS
g
@ 3000
3
&
Lone Pine Flat S$
s 2000
i)
Tds

Tp Thar T8S Gay

1000
SEA LEVEL

1000
Subsurface extent uncertain

for units of John Day Formation

1000 meters = 3281 feet
A, away; T, toward
Many thin stratigraphic units exaggerated in thickness

2000

B B' B" Bl"
METERS Cascade Range crest METERS
4000 4 z 3 4
South Sister 3 x 2|8 é z/5 4 000
x 8 s (3187 m) «5 & L SISTERS FAULT ZONE 2|5 8 215 2
4: $ Ss £ South Sister lava flows Ss 5 8) 3 g B/S 8 . |
3000 é 8 x Ss and deposits & 8 FS z 2g 2 2 8 3000
s , g S

Fy 8 & Sphinx Butte g as 5 DOMES WEST OF THREE CREEK BUTTE 8 > g z = NORTHWEST FLANK,

20004 2 s ° ol S = = g POWELLBUTTES || 5999
2
. : = 5 2 Cline|Buttes Qbn_Qbn_ Forked|Horn Butte DOME COMPLEX
= F = ‘drcb Tdreb Tdb \e/ Tde Tdba Tir
ar QTs QTs Tbdr at i
1000 Tdba \ Talat Qbn 1000
Thr Tar
P po
_| Miocene Tab
SEA LEVEL ~| strata Subsurface extent uncertain SEA LEVEL
Upper Miocene and Pliocene lava flows, chiefly basaltic andesite Fa Be roman

1000 Middle Chiefly John Day Formation - 1000

Miocene Middle Miocene strata, where present, are thin

Strata Middle Miocene strata
2000 — 2000

1000 meters = 3281 feet
Many thin stratigraphic units exaggerated in thickness
South Sister stratigraphic units not shown; till on South Sister cone not shown

Geologic Map of the Bend 30- x 60-Minute Quadrangle, Central Oregon
By
David R. Sherrod!, Edward M. Taylor?, Mark L. Ferns?, William E. Scott‘,

1 U.S. Geological Survey, Hawaii National Park, HI 96718

2 Oregon State University, Corvallis, OR 97331

3 Oregon Department of Geology and Mineral Industries, Baker City, OR 97814
4 U.S. Geological Survey, Vancouver, WA 98661

5 Washington State University, Pullman, WA 99164

© University of New Mexico, Albuquerque, NM_ 87131

Richard M. Conrey*, and Gary A. Smith®

2004

For sale by U.S. Geological Survey, Information Services, Box 25286,
Federal Center, Denver, CO 80225, or call 1~888-ASK-USGS

Available on World Wide Web at http://pubs.usgs.gov/imap/i2683

@Q Pied on recyoed paver