811 °

1 41 °

 AH VRE

CHO ET AU

 DUBOIS

45°

SHELBY

106°

LE I W STOWN

4 °6

45°

 B ZO EMAN

10 °4

WHITE

47°

H RA DIN

 I L ND L O

U P US L H R

1 ° 110° 1 6

116°

108°

GL SA GOW

114° 112°

44°

S NA DPOINT

110°

84 °

 PS R NI GS

EL CK ITY

SPOKANE

O N T A M N A

EK L A AKA

H MA ILTON

49°

104°

G E D VE L N I

ROUN UD P

GREAT FAL SL

MI EL S C TI Y

4 °8

WALLACE

4 °9

 I L N B L I GS

KALISPELL CUT BANK

44°

C A N A D A

JORDAN

1 81 ° 112°

47°

A HS TON

1 60 °

4 °6

W L OIN T O F P

FORSYTH

108°

U TB T E

 Showing location of the Havre 1° x 2° Quadrangle in red

 INDEX TO 1:250,000 TOPOGRAPHIC QUADRANGLES . Rathe

deposits, all composed of till), are distinguished for purposes of reconstruction of glacial histor

substrata or parent materials in which pedologic or agronomic soils are formed

°

This map is a simplified compilation of data from many sources, listed in SOURCES OF INFORM

pgd

 Map units are surficial deposits and materials, not landforms. The deposits that comprise some 

pedology or agronom y

 This map was prepared to serve as a database for compilation of a Quaternary geologic map of the 

 quadrangle, United States and Canada (scale 1:1,000,000). Letter symbols for the map 

several map scales. Some of the map data are simplified and generalized. For example, small areas of 

and materials are distinguished on the basis of genesis, lithology or composition, texture or particle size, and 

shown accurately as small polygons at 1:250,000 scale are omitted here because they are too small to be 

r

 x 6

A

y

) that were mapped separately at 1:31,680 scale 

y

constructional landforms (e.g., ground-moraine deposits, end-moraine deposits, and stagnation-moraine 

, or of 

Lethbridge 4

units are those used for the same units in the Quaternary Geologic Atlas of the United States map series. 

pediment, alluvial-fan, and terrace deposits (map unit 

other physical, chemical, and engineering characteristics. It is not a map of soils that are recognized in 

shown at 1:1,000,000 scale.

, it is a generalized map of soils as recognized in engineering geolog

NOTE:

°

TION, at 

. Deposits 

by Bryant and others (1960) here are combined as single polygons. Many surficial deposits that can be 

, 

are

1957), NW1⁄4 sec. 21, 

written commun. in 1987) and Mammuthus sp. The accretion-gley paleosol between the upper and 

listed

T

lower units of the Havre till were exposed laterally continuously for >2.5 m in 1982. A partial ja

informal

. 32 N., R. 14 E., Mont.—Late Wisconsin, 11.2 m oxidized (and unoxidized?) 

w

Fort Assiniboine till; late Wisconsin or Illinoian, 3.0 m oxidized and unoxidized (Herron Park?) till, 10.1 

, 

allostratigraphic 

m unoxidized (Herron Park?) till; Pleistocene, 0.6 m boulder gravel; middle Pleistocene?, 4.6 m 

including teeth, was collected from debris that slumped from the pit wall. C. S. Churcher identified 

units.

oxidized and unoxidized till (upper unit of Havre till?); middle Pleistocene, 4.0 m oxidized and 

the fossil as 

 

unoxidized lower unit of Havre till, 0.6 m unoxidized lower unit of Havre till

Bison

Unit

 sp. (the horn cores had been scavenged). The slumped sediments were older than 

Big Sandy Creek test holes in the buried ancestral valley of the Missouri River

thicknesses

(Swenson, 1957)

Colton 

•3 NE1⁄4 Sec. 16, 

(1986)

in

T

 

. 31. N., R. 14 E., Mont.—Holocene and late Wisconsin, 3.0 m

T

exposures

oxidized alluvium; late Wisconsin, 11.0 m unoxidized Fort Assiniboine till, 0.6 m sand, 9.6 m 

wo gravel pits represented by a single symbol on map

unoxidized Fort Assiniboine till, gravel, and sand; Pleistocene, 2.1 m boulder gravel, glaciotectonic 

•1 North Havre exposures, NW1⁄4 sec. 5, 

are

raft consisting of 0.3 m sandstone (bedrock?), 0.9 m sand, 0.6 m boulde

T

r

. 32 N., R. 16 E., Mont.—Composite section

maximum

, 7.9 m unoxidized till, and 

from gravel pit and road cuts on slope above pit. Reference section for Fort Assiniboine till, Herron 

0.2 m sandstone (bedrock?), 2.3 m unoxidized till; middle Pleistocene?, 1.2 m oxidized and unoxidized 

thicknesses.

Park till, and Havre till. Late Wisconsin, 4.5 m oxidized lake sand and silt, 0.8 m oxidized Fort 

Havre(?) till; Pleistocene, glaciotectonic raft consisting of 13.7 m shale bedrock, 0.2 m cobble, 7.6 m 

 

shale bedrock, 4.3 m till(?), 0.2 m sandstone bedrock, 2.3 m unoxidized Havre till, 0.2 m sandstone 

Assiniboine till, 1.2 m oxidized lake silt, 1.2 m oxidized sand and gravel; Pleistocene, 20.3 cm paleosol 

T

in 1.1 m oxidized sand and gravel; Illinoian, 1.2 m oxidized Herron Park till sheared into gravel, 4.5 m 

bedrock, 4.1 m Havre till, 0.3 m sandstone bedrock, 0.9 m Havre till(?)

ill

glaciotectonic deposit including ice-thrust masses of Havre till, gravel, and sand and silt; middle 

•4 NE1⁄4 Sec. 16, 

Pleistocene, 1.8 m oxidized upper unit of Havre till, 4.5 m silt and sand, 2.1 m oxidized silt and sand 

T

nomenclature

(channel fill), 4.5 m lake(?) silt and sand including pods of Havre till and subaqueous debris-flow 

. 31 N., R. 14 W

deposits, 1.2 m oxidized and unoxidized upper unit of Havre till, 2.4 m unoxidized clay and silt, 2.4 m 

from

., Mont.—Holocene and late Wisconsin, 11.0 m

accretion-gley paleosol with normal remanent geomagnetic polarit

alluvium (and lake sediment?); late Wisconsin, 1.8 m unoxidized Fort Assiniboine till and sand; 

y

Fullerton

, 3.0 m oxidized and unoxidized 

Pleistocene, 0.9 m gravel, 15.9 m unoxidized till, 1.5 m sand and gravel, 0.9 m interbedded till, sand, 

lower unit of Havre till, 4.5 m unoxidized lake silt with normal remanent polarit

and gravel, 11.3 m till, 1.2 m sand and gravel, 3.4 m unoxidized till

and

y

•5 Laredo test hole in the buried ancestral valley of the Missouri River (Swenson, 1957),

from

, 1.5 m glaciotectonic 

SE1⁄4 sec. 23, 

deposit including lenticular masses of bedrock, till-like diamicton, and gravel; middle or early 

T

, 1.5 m unoxidized cla

youngest

. 31 N., R. 14 E., Mont.—Holocene and late Wisconsin, 5.5 m alluvium; late Wisconsin, 

Pleistocene, 3.7 m Wiota Gravel. The basal gravel is nonglacial alluvium of the ancestral Missouri 

y

4.0 m oxidized Fort Assiniboine till, 3.4 m unoxidized Fort Assiniboine till; Pleistocene, glaciotectonic 

Rive

, 3.0 m unoxidized (Herron Park?) 

to

raft consisting of 3.7 m sandstone (bedrock) and 2.1 m till and sandstone, 2.1 m unoxidized clay; 

r

till, 4.3 m interbedded till and sand; middle Pleistocene, 1.8 m oxidized upper unit of Havre till, 1.5 m 

Illinoian?, 2.1 m oxidized and unoxidized cla

. Reworked glacial erratics from the Canadian Shield have not been observed in the Wiota 

oldest.

y

Gravel in this region. 

 

V

All

the Herron Park till and younger than the Havre till. Section measured in 1980-85

ertebrate fossils in the basal gravel in the Havre area include (?)

Gravel pit adjacent to and west of North Havre pit—R.

IMPOR

Camelops

of

W

T

. Lemke, unpublished field

ANT STR

the

notes 08/06/89. Pre-Illinoian middle Pleistocene, 0.6 m lake sand and silt, 15 cm lake clay and silt, 

minidokae

A

2.4 m oxidized upper unit of Havre till, 15 cm truncated(?) paleosol in lower unit of Havre till – grades 

 of Irvingtonian land mammal age and 

TIGRAPHIC SECTIONS

named

Equus conversidens

laterally into stone line between two Havre till units, 3.4 m oxidized lower unit of Havre till, 3.7 m 

Stratigraphic

lake sand and silt, 0.5 m calcium carbonate-cemented gravel containing abundant reworked glacial 

/

till

calobatus

units

erratic clasts from the Canadian Shield, 1.4 m channel alluvial gravel of ancestral Missouri River 

 (C. S. Churche

units

containing no reworked glacial erratic clasts from the Canadian Shield

r

are

•2 Herron Park test hole in the buried ancestral valley of the Missouri River (Swenson,

•8 Lodge Creek exposure, NW1⁄4 sec. 34, T. 35 N., R. 18 E., Mont.—Late Wisconsin,

3.0 m oxidized and unoxidized Fort Assiniboine till; Illinoian, 1.5 m unoxidized Herron Park till; middle 

Pleistocene, 6.1 m oxidized Havre till, 4.6 m oxidized sand and silt, 6.1 m oxidized Havre till, 3.0 m 

unoxidized Havre till. Measured in 1984

•9 Chapman exposure, SW1⁄4 sec. 23, T. 36 N., R. 27 E., Mont.—Holocene, 1.5 m

sheetwash alluvium (gully fill inset into till); Holocene and late Wisconsin, paleosol in oxidized Loring 

till; Pleistocene, truncated calcic soil pendants in 1.8 m oxidized Illinoian Markles Point till; middle 

Pleistocene, 1.2 m oxidized and unoxidized Perch Bay till; Pleistocene(?), 0.3 m oxidized silt (loess); 

Pliocene, 1.1 m oxidized silt and sand, 4.6 m informal Chapman gravel of Patton (1987). The Perch 

Bay till and the underlying loess have normal remanent geomagnetic polarity. Section measured in 

1983, 1984, and 1986. In an adjacent exposure in 1986, the succession of units, from youngest to 

oldest, was cobble gravel; bouldery Loring till; a glaciotectonic raft of shale bedrock; Markles Point 

till; Perch Bay till; eolian silt and sand; Chapman gravel 

•10 Coburg Coulee exposure, NW1⁄4 sec. 7, T. 34 N., R. 27 E., Mont.—Illinoian, 3 m

oxidized and unoxidized Markles Point till; middle Pleistocene(?), oxidized Perch Bay(?) till composed 

almost entirely of shale fragments; middle Pleistocene, 15 cm leached, gleyed sand (paleosol?), 

oxidized Perch Bay till; Pleistocene(?), oxidized silt (loess). Oldest till unit has normal remanent 

T

geomagnetic polarit

.

y

27 N., R. 23 E., Mont., represented by a single symbol on map

. Measured in 1983. Exposure is an erosional remnant of till that is too small to 

Observation well O-33—Pleistocene, 12.8 m oxidized till, 2.4 m unoxidized till, 6.1 m

map at this scale

unoxidized sand, 3.9 m unoxidized till, 6.1 m gravel, 0.9 m till (of pre-Illinoian age?), 1.5 m gravel

•11 Little Peoples Creek wells—

Observation well O-32—Pleistocene, 9.1 m oxidized till, 10.1 m unoxidized till, 1.5 m

T

sand, 10.7 m unoxidized till, 5.2 m gravel, 3.0 m till (of pre-Illinoian age?)

wo wells (Briar and Christensen, 1993), NW1⁄4 sec. 10, 

•12 USGS Observation Well O-29 (Briar and Christensen, 1993), NE1⁄4 sec. 23, T. 27 N.,

R. 23 E., Mont.—Pleistocene, 9.1 m oxidized till, 7.9 m unoxidized till, 1.8 m sand, 5.4 m gravel, 18.3 

unoxidized upper unit of Havre till, 2.7 m interbedded till and gravel, 1.5 m oxidized and unoxidized 

m unoxidized till (multiple till units?)

lower unit of Havre till, 12.8 m unoxidized Havre till 

•13 USGS Observation 

•6 East Fork Battle Creek exposure, SW1⁄4 sec. 30 and SE1⁄4 sec. 24, 

W

T

ell O-60 (Briar and Christensen, 1993), SW sec. 13, 

. 36 N., R. 19 E., Mont.—Late

T

Wisconsin, oxidized and unoxidized Fort Assiniboine till; Illinoian, 4.6 m unoxidized Herron Park till; 

. 27 N., R.

middle Pleistocene, 12.2 m oxidized and unoxidized upper unit of Havre till, 6.1 m unoxidized sand, 6.1 

24 E., Mont.—Holocene, 0.9 m alluvial gravel; Pleistocene, 3.0 m till(?), 1.2 m gravel, 16.2 m oxidized 

m oxidized and unoxidized lower unit of Havre till. Measured in 1984

and unoxidized till and minor gravel (multiple till units), 19.8 m shale (glaciotectonic raft), 7.6 m sand 

•7 Battle Creek exposure, SW1⁄4 sec. 18, 

and gravel

T. 35 N., R. 19 E., Mont.—Late Wisconsin, Fort

Assiniboine till; Pleistocene, silt; Illinoian, Herron Park till; middle Pleistocene, two distinct units of 

Havre till. Section examined in 1983 

clycrg cax

R

tlx tlx

(e)

tlx

(s) ke

GLACIAL

DEPOSITS

ICE-CONTACT

DEPOSITS

 GLACIO-FLUVIAL

DEPOSITS

ALLUVIAL

DEPOSITS

LACUSTRINE

DEPOSITS

LANDSLIDE

DEPOSITS

 COLLUVIAL

DEPOSITS

BEDROCK

?

afj al

alt

aqa

lca lu lse

?

jea

cad

kg

caa

gg

tks tks

(e) ? asr ?

pgd

?

lx

Holocene

?

Pliocene

QUATERNARY

 LATE WISCONSIN

TERTIARY

ILLINOIAN

late

Pleistocene

 PRE-ILLINOIAN

middle

Pleistocene

Pleistocene

early

Pleistocene

silt loam, and sandy loam; or (3) loamy sand and sandy loam. Nonstratified 

deposits of former lakes. Present beneath flat plains and in small basins 

extures may vary abruptl

verticall

Where 

Thickness 1–5 m, locally >15 m

Y

w

y

r

Lake sand and silt—Grayish-yello

yellowish-gra

some areas, chiefly laminated silt and fine sand. Commonly slumped and 

 LAKE DEPOSITS,

Colluvium—

subsequently the Milk River was incised into the lake deposits. Lateral 

 FLOOD-PLAIN

bedrock in a clayey to sandy matrix. 

y

.

AND EOLIAN SAND

ell stratified; poorly 

Y

alley sides are chiefly 

AND CHANNE

W

structures, and folds, in some places. Generally not faulted. Dessication 

rounded. Clast composition reflects composition of other surficial materials 

, 

y

detrital lignite (bedrock) fragments as la

lca, and lu appl

T

y

discontinuous beds, lenses, or stringers of sand or fine gravel; pockets or 

y

subrounded and rounded erratic limestone, dolomite, and igneous and 

bedding or lenticular bedding; local festoon bedding. Locally fossiliferous 

GLACIOFLUVIA

y

L

HOLOCENE

typically it is sand or pebbly sand. 

, brownish-gra

m, locally >10 m

L

T

L

y

r

ALLUVIUM—

olive-brown, grayish-brown, brown, olive, yellowish-gra

ALLUVIUM

Included in other map units in many areas. Includes some sheetwash 

bedding; weakly laminated in some places. Cla

Thin and discontinuous in some areas. 

crossbedded sand. y

Thickness of alluvium 0.5–3 m; thickness of lake deposits 1–5 m

AND GR

, bluish-gra

g-rafted granules and pebbles, or isolated rafted erratic cobbles 

, gra

postglacial lakes. Local relief 2–4 m. Includes some lake clay and silt, 

remnants are 0.6–2.0 m higher than the modern flood-plain surface. 

terrace remnants are underlain by clay and silt, similar to lake deposits 

y

A

y

typically it is boulders, cobbles, pebbles, and granules of erratic limestone 

y

wind and are overlain by eolian deposits. Mapped in northwest quarter of 

sharply defined to indistinct. Some of the channels and sluiceways are 

, gra y

Channel alluvium is inset into other deposits; flood-plain deposits overlap 

y

plastic and sticky when moist; hard when dr y

montmorillonite. Selenite (gypsum) crystals <6 mm in length are present 

or small channel fills of sand and gravel are common. Dense and compact in 

y

f

Y

y

r

developed buried soils (humic horizons). Mostly stable, with grass cover; 

and sand mixed with minor clay and gravel. Generally well stratified and 

2

 x 2

deglaciation (Greg Snell, U.S. Department of

DESCRIPTION O

, or mottled debris transported and deposited by 

WISCONSIN

T , silty cla

Eolian sand and silt— w

y

hard; subangular blocky structure; not sticky or plastic when moist. 

, broad flats. In some places, lake deposits are overlain by eolian 

gravel and pebbly sand near fan apex, grading to pebbly silt and clay near 

r

in some areas is dominantly redeposited outwash, ice-contact deposits, and 

y

Includes areas of lag sand and gravel over till and (or) bedrock; alluvial-fan 

common in some places. Deposit is susceptible to landslide processes 

y

y

bedrock outcrops. In some places, lake clay and silt are overlain by eolian 

Channel alluvium—Chiefly loose, stratified, poorly-sorted to well-sorted, 

L

, fine to medium sand and (or) coarse sand and gravel; locally very 

massive or weakly bedded. Commonly laminated, locally varved, clay and 

clay are present locall

. 

T

ASH

Conservation Service, written and oral commun., 2005, 2006). If they are 

P

massive. 

are ubiquitous in many areas. 

silt, sand, and fine gravel. Overlain by eolian sand and silt in some places. 

, or mottled windblown sand and silt in 

y

, glaciofluvial gravel and sand deposited by meltwater 

Havre. Small alluvial-fan deposits are included in other map units. 

thickness of deposits is 1–10 m, locally >15 m

Thickness 0.5–8 m

Thickness 0.5–4 m

, black, or mottled cla

Flood-plain alluvium—Chiefly poorly-sorted to well-sorted cla

or stream-eroded till or bedrock dissected by gullies; very thin disintegration 

y

fshore 

T

A

, grayish-yello

yellowish-brown, olive-brown, grayish-brown, brown, olive, yellowish-gra

icebe

maximum 6 m

, yellowish-brown, grayish-brown, brown, 

intercalated with massive, bedded or laminated, silt containing dropstones; in 

1

1964; Colton and others, 1982; Fullerton and others, 2007). 

alley during dissipation of the Havre glacial lobe (see fig. 1), and 

thinner than the given range. 

and subangular blocks, boulders, cobbles, pebbles, and granules of local 

Sheetwash alluvium—Pale-yello

yellowish-gra

y

W

T

AN DEPOSITS—

V

, SHEET

noncalcareous; partly or completely oxidized. Clasts angular to well 

y

hummocky surface topograph

, laterally and 

. Local thin buried soils (humic horizons). Concentrations of 

sediment. Includes some sheetwash alluvium. Descriptions of map units al, 

L

brownish-gra

part. Clasts generally are absent on the surface. Contains local thin, 

, olive-gra

in many areas, concentrated in sand crossbeds. Clasts are chiefly 

abundant in some areas. Generally crossbedded or has crude horizontal 

AND 

deposits here are included in map unit al. 

ellowish-brown, olive-brown, brown, olive, yellowish-gra

the lake deposits

AND CHANNE

units]

Where derived from sand and gravel, 

y

Thickness 1–3 

AND SI

yellowish-gra

Isolated la

local iron oxide stains. Soft to very firm; cohesive and compact. 

vertebrate remains; wood fragments and plant detritus) in some places. 

stratified. Commonly has either obscure bedding or pronounced horizontal 

ge as 1 cm are common in 

Where flood-plain alluvium directly overlies lake cla

. Mapped only in the southeast quarter of the quadrangle. 

y

r

y

beneath lake plains and in small basins formerly occupied by glacial and 

In several areas on the Milk River valley floor east of Harlem low terrace 

The 

glacial lake sediments that were deposited during initial late

brownish-gra

ALLUVIUM

Complex map unit of flood-plain and channel alluvium and lake cla

AND L

Where derived from glacial drift, 

, gra

silt and eolian sand and silt. Lake deposits in many places were reworked by 

silt with faint beds or cross-beds. 

meltwater channels and glacial lake outlet sluiceways. Channel sides are 

y

valley sides in some places. Gullies locally are common on valley sides. 

ellowish-brown, 

, brownish-gra

,

ery 

silt commonly breaks into chips or blocks. Clay minerals are dominantly 

ice-contact sand and gravel, lake deposits, and bedrock outcrops. 

, silt, sand, or gravel lenses 

silt and sand where lake cla

silt, and sand or sheetwash alluvium, in some places it is di

A

VEL—Undivided deposit of lake cla

, gra

places; some rare ice-rafted masses (clasts) of till are 1–2 m in diamete

oxidized throughout. In some places, contains root casts and weakly 

, or mottled, calcareous silt 

and silt.

 COLLUVIUM,

°

isconsin 

y

and sand. 

and shale in a clayey to sandy matrix. 

transported and deposited by unconfined overland flow and rill wash. 

y

Missouri River southwest of Havre.

ello

ery friable; weakly compact; slightly 

w

, or mottled cla

Calcareous. Poorly to well stratified; poorly to well sorted. Poorly sorted 

valley sides; in some places it mantles much of the fill on the valley floo

olive-gra

DEPOSITS—Complex map unit on valley sides and eroded uplands. 

. Locally gritt

calcium carbonate concretions locally are present in upper part. Gullies are 

moist and hard where dr

Includes some till with a thin veneer of silt and cla

ice-contact and outwash sand and gravel, small lake delta deposits, and 

distinguish the deposits.

AND SI

y

or mottled, calcareous clay and silt. Generally stratified; well sorted; 

Graded beds, silt blebs and nodules, or rip-up clasts of till or lake silt and 

y

W

 quadrangle (Jensen and

Agriculture, Natural Resources 

 MA

Nonstratified or faintly stratified; nonsorted or poorly sorted. Commonly 

horizons) locally are present in the colluvium; lignite (bedrock) fragments 

, 

, silty clay loam, and clay loam; (2) clay loam, 

brown, brownish-gra y

calcium carbonate in some places; stained by iron oxides locall

y

alluvium and flood-plain and channel alluvium. Mapped only southwest of 

Distinction of map units cad and caa is arbitrary in some areas. Combined 

fluvial, glaciofluvial, and glaciolacustrine deposits and till. 

y

mouths of gullies; lag boulder and cobble accumulations; sheetwash-eroded 

, silty cla

f

alluvium. 

 LAKE CL

w

in upper part. Upper part generally is clast free; in some places, 

. Strongly contorted, with slump structures, load 

Thickness 0.5–3 m; 

w

containing scattered granules or small pebbles. Commonly interbedded or 

ALLUVIUM,

arnes, 

V

[Map unit thickness is typical range; in some areas the map units may be thicker or 

Where derived from local bedrock, colluvium typically is angular 

Thickness 0.5–5 m

, yellowish-brown, olive-brown, brown, olive, 

Descriptions of lake deposits in map units lca and lse appl

 F

 FLOOD-PLAIN

2

m, locally >15 m

, silt, sand, and gravel. Calcareous or 

badland terrain.

clay loam, clayey silt, and silt with scattered granules and pebbles; locall

formerly occupied by glacial and postglacial lakes and ponds. Flat to 

y

y

streams meander across old lake plains, alluvium is chiefly redeposited lake 

, SI

, bluish-green, 

, 

g-rafted granules, pebbles, cobbles, and boulders are common in lower 

y

contorted on hillslopes. Detrital fragments of lignite (bedrock) are abundant 

The terrace 

Y

shifting of the Milk River in postglacial time resulted in removal of most of 

All of the named till units are informal allostratigraphic 

, olive-gra

 LAKE

sorted to well sorted. 

ellowish-brown, grayish-brown, 

colluvium, sheetwash alluvium, till, lake deposits, and bedrock outcrops. 

L

ASH

cracks are common in some places. Commonly oxidized in upper 1–2 m; 

and bedrock in the drainage basin. Fossiliferous (gastropod, pelecypod, and 

loam, sandy clay loam, sandy loam, or fine sand. Moderately to well 

. 

r

y

, SAND,

, olive-gra

pods of icebe

, brownish-gra

metamorphic rocks that were ice rafted or reworked from till. Present 

(chiefly vertebrate remains).

They have been interpreted to be 

, 

y

T—Complex map unit of lake sand and 

ypically loose, homogeneous, massive, fine sand and 

 DEPOSITS—Complex map unit in abandoned 

, brownish-gra

ge boulders or lag deposits of cobbles and boulders are present on 

Y

y

1

V

alluvium, alluvial-fan deposits, alluvium beneath low terraces, outwash and 

y

Overlapped by flood-plain alluvium adjacent to some streams. Includes lake 

, 

 LAKE CL

A

y

or boulders. Interbedded with sand, fine gravel, till, or flowtill in some 

ypically 

y

flood-plain and channel alluvium, and till. In many areas, overlies lake clay 

farther east in the adjacent Glasgow 1

W

, gra

AND LAKE DEPOSITS—

, silt, 

TE

and dolomite, erratic igneous and metamorphic rocks, and local sandstone 

, or mottled alluvium 

the quadrangle and also over the buried bedrock valley of the ancestral 

Y

V

shallo

y , silt, sand, and gravel. 

some lake deposits. Sheetwash alluvium locally overlaps other deposits on 

, 

AND LANDSLIDE 

y . Dry clay and 

locally in fractures and are abundant in saline lake sediment. Secondary 

Alluvium 

most places. Clayey alluvium is moderately plastic, soft, and sticky where 

, silt, and sand have not been distinguished. 

ficult to 

pebbl

, olive-black, bluish-black, black, 

. 

local blowouts. Undulating or rolling topograph

well sorted. 

Thickness 1–8 m, locally >10 m

 SHEET

°

F

mass-movement processes. Calcareous or noncalcareous. Loose to compact. 

Alluvium in broad alluvial flats commonly is alkaline. 

Three or more buried soils (humic 

y

ypically (1) cla y

, yellowish-brown, olive-brown, grayish-brown, 

, gra

Generally clast free. Contains discontinuous accumulations of secondary 

sand and silt. Locall

toe. Clasts are subangular to well rounded. Includes some sheetwash 

. 

Colluvium—Similar to deposits in map unit caa. 

lake deposits. Southwest of Havre, alluvium overlies a thick fill of older 

, gra

and sheetwash-alluvium fan or apron deposits at bases of hillslopes and at 

y

(chiefly slump) in exposures (see map unit jea). Most deposits are o

. 

. Includes some 

silt and sand, sheetwash alluvium, alluvial-fan deposits, or flood-plain 

T—Pale-yello

poorly sorted sandy shale gravel. Cobbles and boulders are common to 

silty clay in lower part and massive or horizontally-bedded silty clay and silt 

y

ypically horizontally bedded or massive, fine or medium sand 

V

lacustrine in origin, a glacial lake expanded westward in the Milk River 

 UNITS

w

Includes inset and overlapping flood-plain and channel alluvium. 

blanket-like deposits; local low dunes. Calcareous. 

. 

ALLUVIALstreams underlies the lake and alluvial deposits. 

Thickness 0.5–10 m; maximum thickness >10 m

Sheetwash alluvium—Similar to deposits in map unit caa. 

 COLLUVIUM

Thickness 1–6 

y

residuum on bedrock; includes extensive areas of bedrock outcrop and local 

, silty 

r

alkaline when moist; friable and hard or very hard when dr

tough, hard, and blocky where dr

, brownish-gra

siltstone, or shale; slump topography is conspicuous. Includes some loamy 

V

brown, yellowish-gra

overland flow and rill wash. Similar to deposits in map unit caa.

deposits. Includes areas of till that were modified by waves and currents in 

y

DEPOSITS—Mapped only in the eastern part of the Bearpaw Mountains and 

generally include thicknesses of older subsurface tills 

T

r

VEL—Complex map unit composed of 

la

abundant erratic limestone and dolomite from Saskatchewan and Manitoba 

Y

subangular local bedrock. Clasts are chiefly syenite, monzonite, schist, 

yellowish-brown, orange-brown, olive-brown, grayish-brown, brown, 

y

IMPO

A

Fossiliferous (gastropod tests) locall

Coarse

montmorillonite. Granules and pebbles are chiefly local clastic sedimentary 

olive-gra

outcrops. 

places, till is interbedded with, intercalated with, or contains lenses, pods, 

, silt, sand, or gravel. Generally nonstratified; nonsorted 

0.3–4 m

bedrock outcrops. Locally overlain by colluvium, sheetwash alluvium, lake 

gin of the Little Rocky Mountains. Most of the individual 

W

separated by elongate swales. Clasts in rockslide deposits are granules to 

PLEIS

gest erratic 

, silt, sand, and gravel of late

SECTIONS). Pebbles in typical till are chiefly subangular to rounded erratic 

subangular granules, pebbles, cobbles, boulders, channers, flagstones, slabs, 

T

—White, pink, yello

some landslide deposits, flood-plain and channel alluvium, pediment, 

 CL

, yellowish-gra

Y

—Complex map unit in the Bearpaw 

, or mottled, calcareous or noncalcareous cla

AN

WISCONSIN

common in many areas. Generally calcareous and alkaline; saline in some 

generally southeastward, recorded by the Snake Butte boulder train 

moist and loose when dr

areas. 

y

HOLOCENE, L

Loose to compact. 

or subangular granules, pebbles, cobbles, and boulders of local bedrock from 

y

, silt, and sand, or eolian sand and silt.

y

(1964). Slump-block landslide deposits are masses of bedrock and 

coated by powdery calcium carbonate or gypsum, or both. Joint or parting 

bedrock outcrops.

 LAKE CL

. Clasts of older till and clasts of lignite 

y

are chiefly angular to subrounded shale, siltstone, and soft sandstone; where 

map unit cax). Locally cemented by secondary calcium carbonate. In some 

y

 COLLUVIUM,

, 

y

A The lake deposits in these 

interbedded with well-sorted, pebbl

ypical till is pale-yello

claystone, mudstone, and a

lake deposits, commonly there is not a sharp contact between the deposits. 

, or mottled, calcareous clay loam and loam; in 

T

, silty cla

bedrock. Material has not been transported by mass-movement processes. 

slightly sticky to stick

hillslopes; slumps in exposures. 

minor moraine deposits (see symbol). Maximum slope angles are generally 

w

Fragments of lignite (bedrock) are ubiquitous in till. Nearly pebble free to 

, SI

ge as 2 m in diameter locally are included in the till. 

, or mottled loam and 

T

alluvial deposits (map unit pgd). Includes some talus deposits, landslide 

, gra

A

y

lake deposits. Ice-dammed lakes formed in valleys on the north ma

age has been observed beneath lake deposits and beneath Herron Park till in 

The till 

silty clay loam, clay loam, or loam. Fine-grained residual materials or 

intercalated, or interbedded with eolian sand and silt or flood-plain alluvium 

w

conglomerate. In some places contains lignite (bedrock) fragments, 

AND MIDDLE PLEIS

y

 LOAM 2

or compact. Shale fragments are common in many places, particularly in 

dr

ill is thin and discontinuous in many areas; 

OCENE

. Local relief is generally <3 m. 

The physical properties of the transported materials are not 

, SAND,

Noncalcareous or calcareous. Nonstratified or weakly stratified; nonsorted 

r

fluvial-terrace deposits, and disintegration residuum and colluvium derived 

noncalcareous. Nonstratified or weakly stratified; nonsorted or poorly 

loam and sandy loam in the Little Rocky Mountains. Calcareous or 

, olive-gra

the Bearpaw Mountains during maximum late

thinly laminated, or with weak horizontal bedding. Disseminated o

, slightly plastic or plastic, and 

, and plastic where moist; 

y

deposits are abundant in some places where bedrock is claystone, mudstone, 

ellowish-brown, olive-brown, grayish-brown, 

, olive-gra

residuum to or into bedrock. 

have sharp edges; blocky structure in some other places. Parting typically is 

(symbol IT), flowtill, mud-flow deposits, debris-flow deposits, and landslide 

AND ROCKSLIDE 

thickness >15 m. Overlies older till in most areas; till thicknesses of >10 m 

average diameter of boulders is la

A

. Pebbly to cobbly; 

and other igneous and metamorphic rocks from the Canadian Shield; less 

(e.g., on Snake Butte). 

. In most places, clasts are angular and 

ASH

brownish-gra

isconsin glaciation 

glaciation (represented by subsurface Havre till in the quadrangle (see 

L

matter is abundant in some places; local thin buried soils (humic horizons). 

. 

. Clay minerals are dominantly 

, 

alluvial-terrace deposits; flood-plain and channel alluvium; and bedrock 

bedrock, the matrix commonly is >90 percent shale fragments. In some 

y

Sheetwash alluvium—Alluvium transported and deposited by unconfined 

Thickness 

cover of lake cla

and ice-contact sand and gravel, flood-plain and channel alluvium, and 

r

of some deposits form sub-parallel, arcuate, concentric, hummocky ridges, 

r

y

gest clasts locally are boulders or blocks. Clasts generally are angular and 

 LOAM 2

shale. Glacial erratics from Canada are present in some places. Includes 

, brownish-orange, 

w

YE 1

y

T

. Fragments of lignite (bedrock) are 

1). Ice movement north and east of Havre in the Havre lobe (fig. 1) was 

-grained materials or deposits are nonsticky and nonplastic when 

metamorphic rocks in glaciated areas. Included in other map units in many 

, bluish-gra

processes. Nonstratified or weakly stratified; nonsorted; commonly massive. 

Where derived from bedrock, clasts typically are angular 

areas, gritty or mealy; crude fissilit

y

scale. Includes the Myrtle Butte rockslide deposits of Hearn and others 

weakly-developed joints are common; in some places, joint surfaces are 

jumbled blocks. Includes areas of colluvium, sheetwash alluvium, and 

Thickness 3–5 m, locally >10m

OCENE

r

, brownish-gra

W

Canadian Shield; where till is derived primarily from local bedrock, pebbles 

flow breccia; in some places clasts are sandstone, mudstone, or shale (see 

Thickness 0.5–>6 m; maximum >15 m

, olive-gra

Y

w

, silty cla

STR

Y

stringers, pods, and lenses of granule or pebble gravel. Commonly 

T

. Clasts generally are sandstone, shale, siltstone, 

Where sheetwash alluvium directly overlies flood-plain alluvium or 

Landslide deposits—Similar to deposits in map unit jea.

y

TE PLEIS

y

(humic horizons).

Residuum—Material formed chiefly in place by mechanical disintegration of 

but not hard. Sandy till is loose to firm; silty till is firm. Clayey till is soft, 

ill everywhere is generally unstable; it moves by creep on 

surface topograph

sediment (stagnation-moraine deposits), small end-moraine deposits, and 

or no flo

(gypsum) crystals 1-3 mm long are present on joint surfaces in some places. 

Y

r

y

surficial deposits higher on same slopes; in some places derived from 

y

 DISINTEGR

grayish-brown, brown, reddish-gra

possibly pre-Illinoian age. See map units lca, lse, and lu for descriptions of 

observed beneath and between lake deposits, and Havre till of pre-Illinoian 

Loring till and Fort

, coarse silt and very fine sand. Mixed, 

, grayish-yello

gillaceous limestone; local chert-pebble 

, silty clay loam, silt loam, sandy cla

OCENE

 COLLUVIUM

structures that are inherited from the original bedrock. Loosely consolidated 

, and slightly plastic to plastic when moist; hard when 

T

T

°

are more abundant in till of late

T

locally are included in the till (see IMPORTANT STRATIGRAPHIC

glaciated igneous intrusions it includes some till and glacial erratic clasts. 

a

some flood-plain and channel alluvium, pediment, alluvial-fan, and 

, or mottled 

3

y

gin of 

included in the map unit. Includes gravelly lake delta deposits. 

movement of ice in the

to moderately well stratified; poorly or moderately well sorted. Massive, 

y

y

grayish-brown, brown, brownish-olive, olive, yellowish-gra

crystals, or very thin intervals of ironstone. Included small landslide 

sandy loam. 

Y

y

Thin and discontinuous; pedologic soils typically extend through the 

. Dry till in some places breaks into small angular flakes and plates that 

age that is exposed at the surface. Includes some glaciotectonic deposits 

Thickness 0.5–2 m; maximum 

sedimentary structures of slumped materials are disturbed but retained. 

isconsin age than in older tills; also, 

AND GR

y

subangular to well-rounded, erratic granite, pegmatite, gneiss, schist, diorite, 

the limit of glacial till; in glaciated terrain mapped on igneous intrusions 

y

W

, 

W

(associated with map unit tks), and possibly during at least one pre-Illinoian 

1–>5 m

quadrangle is Fort

ganic 

y

y

y

colluvium derived from igneous rocks; pediment, alluvial-fan, and 

ery gravelly in some places; where till directly overlies shale 

Thickness 0.3–0.5 m

glacial lakes, with a surface litter of cobbles and boulders or a discontinuous 

, silt, and sand. Includes some lake delta deposits, outwash 

on the north ma

irregular or prismatic. Clay is dominantly montmorillonite. 

oes 

ger than that in older tills. La

lake cla

r

and quartzite. 

Thickness 0.3–>6 m

 COLLUVIUM

gneiss, quartzite, limestone, dolomite, sandstone, siltstone, claystone, and 

w

brownish-yello

A

ALLUVIUM

, gra

R

TE

y

Assiniboine till deposited by the Havre glacial lobe (fig. 

r

rocks; minor redeposited erratic limestone, dolomite, and igneous and 

y

Colluvium—Debris transported and deposited primarily by mass-movement 

and stringers of cla

or very poorly sorted. Commonly massive; cohesive to friable. In some 

HOLOCENE

cla

landslide deposits elsewhere in the quadrangle are too small to map at this 

idely spaced, 

slabs and blocks; some blocks are >3 m in diameter; some deposits are 

T

boulders are >2 m in diamete

y

limestone and dolomite and erratic igneous and metamorphic rocks from the 

and blocks of syenite, latite, trachyte, shonkinite, monzonite, phonolite, and 

alluvial-fan, and alluvial-terrace deposits, and extensive bedrock outcrops. 

 OR LOAM

y

Mountains and in the northern Little Rocky Mountains. Pale-yello

y

T

LOAM

places. Clast free or with scattered granules and small pebbles, or with 

(Knechtel, 1942) and ice-molded landforms that are shown as a symbol. 

y

, gra

A

higher slopes, in a clayey or loamy matrix. Locally contains buried soils 

Thickness 1–15 m 

. Generally loosely compact or compact, 

 Ground-moraine deposits—Integrated drainage; flat, rolling, or undulating 

. In some places, includes collapsed supraglacial 

unconsolidated materials that rotated or slid downslope as a unit, with little 

surfaces are locally weakly stained by iron or manganese oxides. Selenite 

A

(bedrock) as la

, gra

derived from

places includes buried soils (humic horizons). Derived from bedrock or 

, brownish-gra

2

reddish-brown, orange-brown, yellowish-brown, olive-brown, 

, 

isconsin age, Illinoian age, and 

TIGRAPHIC SECTIONS). 

areas have not been studied. Herron Park till of Illinoian age has been 

TILL—Sediment deposited chiefly by ice of a Laurentide continental ice sheet. 

Assiniboine till of Fullerton and Colton (1986). 

y

w

r

Thickness 1–4 m, locally >10 m

some areas it is cla

OCENE,

y

T

Y

Nonsorted; massive or has faint stratification, bedding, or other sedimentary 

y

AND PLEIS

less than 4

. 

very pebbly; cobbles and boulders are rare to abundant. Boulders typically 

L

Glaciotectonic blocks or rafts of shale or sandstone tens of meters in length 

sandy loam derived from mafic and felsic igneous rocks. On isolated 

ertiary and Quaternary gravel, pebbles are mainly quartzite, 

deposits, debris-flow deposits, and extensive bedrock outcrops. Includes 

y

TION RESIDUUM,

, yellowish-gra

r

the areas mapped. Small areas of exposed Herron Park and Havre till are 

north of the Boundary Plateau is Loring till deposited by southward 

surficial deposits are slightly sticky or stick

in some places. Clayey alluvium is soft, stick

, yellowish-brown, olive-brown, 

calcareous or ferruginous concretions, chert nodules, selenite (gypsum) 

, or 

—

lower part; locally residuum contains thin layers of platy shale fragments. 

y

locally the map unit includes exhumed till of Illinoian and (or) pre-Illinoian 

 SLUMP-BLOCK LANDSLIDE DEPOSITS

greatly altered; original textures, stratification, bedding, and other 

W

or poorly sorted. Nonplastic when damp; firm when dr

gillite, chert, and chert conglomerate. Cobbles and boulders are chiefly 

from sedimentary rocks. Mapped mainly in the Bearpaw Mountains beyond 

sorted. Generally pebbly or cobbl

AND SHEET

y

(associated with map unit tlx), during maximum Illinoian glaciation 

Thickness 

Whitewater glacial lobe; till elsewhere in the 

dominantly granules and pebbles. 

gest erratic boulders are >2 m in diamete

OCENE

downstream direction in valley train deposits. Clast composition generally is 

w , grayish-yello

. Generally 

inset flood-plain and channel alluvium, and bedrock outcrops. In some areas, 

Deposits underlie terrace remnants. Upper part commonly is firm to 

r

The till overlies 

overlies bedrock. 

T

sedimentary structures of the deglacial outwash and early postglacial 

, and the deposits have not been distinguished on 

olive-gra

ill characterized by (1) broad, long belts of hummocky 

deposits are transitional, and contacts are arbitrar

northeast of the Boundary Plateau. In some areas, deposits include 

, or mottled, calcareous sand and gravel and minor silt. 

Sand and gravel in some places are replaced laterally by till end-moraine 

y

carbonate in zones; intense iron-oxide stains on some clasts. Clasts are 

sedimentary rocks. Fluvial deposits are present beneath multiple terrace 

where overlain by weathered eolian silt and sand. Includes some 

w

y

commonly breaks through (rather than around) granules of sandstone, 

recession of an ice ma

discontinuous lake cla

places, or is covered by a veneer of eolian sand and silt. Discontinuous lag 

dominantly subangular to rounded igneous and metamorphic rocks from the 

ALLUVIA

r

reddish-brown, yellowish-brown, olive-brown, grayish-brown, brown, olive, 

y

alluvium, lake deposits, and till units of late

y

surfaces. Giant ripples of sand and gravel are present on some surfaces. 

boulder gravel. Local lenses or beds of silt and clay; local boulder beds; 

gin of the Bearpaw Mountains possibly 

AN,

Y

y

y

, discontinuous, sharply defined 

. 

supraglacial lake cla

w

. Locall

T

LOAM

w

silty clay loam, sandy cla

y

deglaciation. 

kame-moraine deposits (map unit ke) arbitrarily in some areas. Includes 

surfaces. In general, boulders are less abundant in till of Illinoian age than in 

Where till is thin 

AND LACUSTRINE-FIL A

r

, brownish-gra

Thin and discontinuous in 

isconsin and Illinoian age 

postglacial alluvium. Precipitation and runo

T

 End moraine-deposits—

White, pink, reddish-yello

, brownish-gra

, or mottled gravel, sand, and silt. Calcareous 

gins. Some 

locally >20 m

gravel. Glacial, glaciolacustrine, glaciofluvial, and alluvial sediments were 

, reddish-brown, yellowish-brown, 

dominantly boulder or cobble gravel; in some places, pebbly silt and fine 

 SAND

y

Y

y

nonsorted or very poorly sorted. In some places, till is interbedded with, or 

surfaces commonly are coated by seams of secondary calcium carbonate or 

onto the plateau from the west and buried some of the arcuate ridges beneath 

y

W

W

ge cobbles and boulders are dominantly 

r

the fill deposits are exposed as a result of intense dissection and modification 

pegmatite, gneiss, schist, diorite, and other igneous and metamorphic rocks). 

y

colluvium, sheetwash alluvium, and bedrock outcrops. Overlain by thin 

Assiniboine till and Herron Park till, respectivel

present for several thousand years after initial deglaciation, and glacial, 

T

to very well rounded; diameter of la

w

y

and silt matrix. Clasts in pediment and alluvial-fan deposits are chiefly 

common on the surface in many areas. Local relief in some places is 4–10 

ill characterized by hummocky or 

stagnation-moraine deposits and ground-moraine or end-moraine deposits 

, olive-gra

y

A

(clasts) of redeposited till. Fragments of lignite (derived from bedrock) are 

y

pediment deposits and terrace deposits along the ma

Mountains and Little Rocky Mountains. 

, olive-gra

, silt, sand, or gravel. Commonly 

 very bouldery accumulation of till on the Boundary 

surfaces. Stains, flecks, or scales of iron and manganese oxides are common 

not destroy the morphology of the ridges (see symbol for limit of the glacial 

overlain by till or flowtill; in some areas overlain by eolian silt and sand. 

AND GR

quartzite, limestone, and dolomite clasts from Canada are less abundant. 

topograph

The alluvial and lacustrine fill deposits include, 

manganese oxides; gravel is locally cemented by secondary calcium 

, or mottled, calcareous sand, 

T

AND PLIOCENE

w

, subrounded, or 

arkosic quartzite, and sedimentary limestone, dolomite, conglomerate, 

T

. Generally lacks distinct, continuous 

.

brownish-gra

 KAME-MORAINE DEPOSITS—Ice-contact gravel, sand, and minor silt similar 

discontinuous laterall

w

Boulder litters are present locally on the surface. Local relief is generally 

the limit of glacial till commonly are covered by eolian sand and silt, 

(1986). 

to very sticky and slightly plastic to plastic when moist; hard and blocky 

shown by a symbol. Maximum thickness >10 m. 

pebbly; cobbles and boulders are rare to abundant. Clasts in some areas are 

r

T

meltwater streams. Pale-yello

°

w

age; and glacial lake deposits of pre-Illinoian age. 

scars. Includes some till, ice-contact sand and gravel, lake-delta deposits, 

sand and gravel deposited by a catastrophic, glacial-lake, outburst flood. 

well-sorted sand, (2) pebbly sand with ripple-drift, cut-and-fill, plana

ertiary sand and gravel nearly everywhere (Patton, 1987) and the gravel 

The exposed gravel is too thin to be mapped at this scale. 

, clast composition, and 

,

r

, 

T

between end-moraine deposits and stagnation-moraine or ground-moraine 

are abundant in some areas. Local relief is generally >3 m; locally 40 m 

y

hummocks and hills (kames) of sand and gravel. Relief is generally 4–10 m. 

common. Gravel locally is cemented by iron oxides or secondary calcium 

Mountains they are mafic and felsic intrusive and volcanic rocks, and similar 

Gravel is locally cemented by secondary calcium carbonate, particularly 

Herron Park till deposited by eastward movement of ice. Pale-yello

, gra

. Dry till in some places breaks into small, irregular pieces; 

The arcuate end-moraine ridges (shown by a symbol) indicate northward 

The surface is intensely deflated in many 

. Erratic pebbles are 

redeposited quartzite, a

, 

artificial excavations does not slump readil

overlain by eolian deposits, channel and flood-plain alluvium, sheetwash 

and gravel is overlain by lake cla

sand containing cobbles and boulders. Boulders are common on some 

trough crossbeds, or (3) interbedded pebbly sand and pebble, cobble, or 

r

F

 FLOOD DEPOSITS—

, brownish-gra

w

y

unit includes collapsed glacial sediment (till and flowtill), collapsed 

extures vary abruptl

valley of the Milk River east of Chinook. 

y

 ICE-CON

till. 

in the Bearpaw Mountains are older than the late

outcrops. 

ILLINOIAN

grayish-yello

mottled, calcareous clay loam, loam, or sandy loam; in some areas, matrix is 

irregular or prismatic; platy structure locall

gin on the Boundary Plateau during initial Illinoian 

, silt, sand, and gravel. Distinguished from 

surfaces; isolated lag cobbles and boulders are widely scattered on till 

subrounded shale, siltstone, and soft sandstone.

 DEPOSITS—

older gravel. Boulders and la

y

W

silt and sand.

 Some of the sand and gravel mapped as outwash deposits possibly is early 

Plateau. 

 Ground-moraine deposits—Thickness generally 0.3–3 m. 

AND FLUVIAL-TERRACE DEPOSITS—

olive, yellowish-gra y

y

r

Thickness 4–15 m, 

, silt, and sand, and outwash and ice-contact sand and 

w

, map unit is 

T

ypicall

isconsin till. 

 OR SAND

brownish-olive, olive, yellowish-gra

, or sandy clay loam. Generally nonstratified; 

montmorillonite. idely spaced polygonal joints in some areas; joint 

Those ridges later were overridden by ice that (1) readvanced 

Also includes some outwash sand and gravel, lake cla

r

from older gravel, pebbles are dominantly quartzite, a

buried valley of the ancestral Missouri River in the vicinity of Havre, where 

subrounded, reworked, glacial erratics (limestone, dolomite, granite, 

, olive-gra

includes some flood-plain and channel alluvium, outwash sand and gravel, 

f likely were greater than at 

PLEIS

finer in downstream direction in valley train deposits. Clasts are subangular 

, yello

, gra

moderately well sorted. Boulders, cobbles, pebbles, and granules in a sand 

deposits. Shallow closed depressions and lag cobbles and boulders are 

T

buried ice long after initial deglaciation. In some areas, boundaries between 

y

inclusions, or clasts of cla

AND GR

resistant erratic clasts are more abundant. In some places, includes blocks 

ill overlies 

Y

y

y

1–4 mm long, or clusters or crusts of crystals, are present on some joint 

plateau from the northeast and overrode many of the arcuate ridges but did 

flood-plain and channel alluvium, till, and bedrock outcrops. Locally 

 OUT

other igneous and metamorphic rocks from the Canadian Shield; erratic 

conglomerate. Drainage is integrated; flat, rolling, or undulating surface 

many areas. Clasts in some places are intensely stained by iron oxides or 

y

, of Fullerton and 

redeposited as alluvial fills. 

gest clasts generally decreases in 

orange-brown, olive-brown, brown, brownish-yello

r

Little Rocky Mountains clasts are chiefly gneiss, schist, syenite, monzonite, 

y

y

, 

poorly to moderately sorted. Irregularly bedded to well bedded; beds are 

sediment collapsed when ice subsequently melted. Pale-yello

hummocky to knobb

irregular hills. Commonly pitted with ice-block depressions (kettles). 

gins of the Bearpaw 

The fluvial deposits in areas beyond 

ice sheet. Markles Point till and Herron Park till of Fullerton and Colton 

compact; resists penetration by pick or shovel. Clayey till is slightly sticky 

end-moraine ridges of cobbly sandy loam till on the Boundary Plateau are 

Generally oxidized throughout where thin. Nearly pebble free to very 

MIDDLE PLEIS

VEL— Sediment deposited in subaerial 

. Maximum slope angles in most places are <4

overbank and channel alluvium and pond or lake deposits of pre-Illinoian 

is1–5 m. Some surfaces are marked by braided or anastomosed channel 

, or mottled, calcareous 

stratified; poorly to well sorted. Stratification typically (1) horizontal beds of 

Boundary Plateau is mapped as directly overlying bedrock. 

T

y

T

y

 End-moraine deposits—

deposits (ke) that are included in the map unit. In some areas, boundaries 

ponds, sloughs, and depressions are common. Ice-block depressions (kettles) 

Thickness 4–20 m, locally 40 m

, gra

segments of end moraines; gently to steeply sloping ridges or aligned 

. Faults, folds, and slump and collapse structures are 

brownish-yello

sandstone, mudstone, siltstone, claystone, and shale; in the Bearpaw 

and currents in lakes; the ice-contact deposits are overlain by thin, 

surfaces of some of the higher (older) deposits are buried by those deposits. 

The surface till on the western end of the Boundary Plateau is 

y

r

 

similar to that in local till; locally dominantly shale or dominantly 

, brownish-yello w

stable on hillslopes; till in natural exposures (such as stream cuts) and 

The fill deposits are 

deposits were modified by waves and currents in lakes, and outwash sand 

compact, plane-bedded sand and gravel; lower part is poorly sorted, massive 

, or 

ill mapped on the north ma

alluvium are simila

ALLUVIALpublished maps

y

or undulating ridges or (2) belts of narro

glaciotectonically folded and ice-thrust masses of bedrock (symbol IT). Map 

T

deposits that are included in the map unit. Mapped only in or adjacent to the 

, laterally and verticall

subrounded to well rounded; clast composition is similar to that of associated 

surfaces in the Bearpaw and Little Rocky Mountains; at least three surfaces 

disintegration residuum, colluvium, sheetwash alluvium, and bedrock 

, 

, or 

limestone, dolomite, granite, gneiss, and schist. Parting typically is crudely 

r

y

deposits of granules and pebbles are common on washed or deflated till 

Canadian Shield and limestone and dolomite from Canada. 

L

and derived from local bedrock, pebbles are chiefly subangular to 

L

gillite, chert, and chert conglomerate derived from 

yellowish-gra

. 

, silt, and sand. Locally overlain by eolian 

Mapped only in the northeast part of the quadrangle north of the Boundary 

local blocks (clasts) of till or masses of flowtill. 

includes exhumed till of pre-Illinoian age. 

ellowish-brown, olive-brown, grayish-brown, brown, 

, olive-gra

, gra

ridges, that delineate the configurations of vanished ice ma

y

, grayish-yello

Thickness 4–l5 m, locally >20 m

y

AC

T

W

Thickness generally 1–4 m, locally >10 m

Y

, yellowish-brown, olive-brown, grayish-brown, brown, 

y

. Clay minerals are dominantly 

W

some kame-moraine deposits, kame-delta deposits, and lake-delta deposits. 

till of late

Where till is derived chiefly 

 fill deposit in the 

ge cobbles are chiefly subangular to 

some areas. Includes some minor moraine deposits (see symbol). Map unit 

y

(Fort

Thickness 1–4 m, locally >10 m

f

Thickness 1–>10 m

extures generally become 

A

w

y

or non-calcareous. Poorly to moderately well stratified; poorly to 

mapped end-moraine deposits are suites or complexes of push-moraine 

 Stagnation-moraine deposits—

redeposited by mass movement (flow and sliding) as a result of melting of 

olive-brown, grayish-brown, brown, olive, yellowish-gra

sand. Sand and gravel commonly are interbedded with or contain lenses, 

, shale clasts are much less abundant than in associated till; 

T

 LOAM

, brownish-gra

contains lenses, pods, and stringers of, cla

by powdery calcium carbonate and (or) gypsum. Selenite (gypsum) crystals 

the mapped bouldery end moraine deposit, and (2) readvanced onto the 

, silt, and sand, inset 

isconsin age. La

ASH SAND

subangular to well-rounded granite, pegmatite, gneiss, schist, diorite, and 

gillite, chert, and chert 

by construction activities. 

Fragments of lignite (derived from bedrock) are abundant and ubiquitous in 

, gra

sheetwash alluvium or eolian silt and sand in many places. 

y

ice-contact, glaciofluvial, and glaciolacustrine sediments were eroded and 

OCENE

r

, yellowish-brown, reddish-brown, 

subangular; clasts in fluvial-terrace deposits are subangula

rounded; clasts are bedrock lithologies from the same drainage area. In the 

m. 

knob-and-kettle collapsed topograph

are transitional and contacts are arbitrar

y

, silt, till, or flowtill. Poorly to well stratified; 

VEL—Deposited on or against glacial ice; 

abundant and ubiquitous in many places. Surfaces are flat to undulating or 

. In some areas deposits form isolated mounds or 

r

TILL—Sediment deposited by a Laurentide continental 

y

massive; cohesive and friable; crudely fissile. Generally compact or very 

Plateau that marks the limit of a glacial readvance. Smaller arcuate 

on joint and parting surfaces. Fragments of lignite (bedrock) are ubiquitous. 

readvance)

Thickness 1–10 m, locally >15 m

A

La

y

from younger to older; glacial lake sediment of Illinoian age; nonglacial 

carbonate. Surfaces are smooth, undulating, or gently rolling. Local relief 

pebbly sand, and gravel; locally pebbly sand and silt. Poorly to well 

ill on the 

The surface morpholog

 PEDIMEN

, yellowish-gra

ill end-moraine deposits are locally replaced laterally by kame-moraine 

ridges. Nonintegrated or poorly integrated drainage; shallow ephemeral 

y

to deposits in map unit kg. Description of map unit kg applies. Comprises 

y

, 

3–15 m, locally >20 m. In some places, deposits were modified by waves 

colluvium, and sheetwash alluvium; all of the boulders and cobbles on the 

when dr

 

Map I-235, scale 1:31,680.

r

Agricultural Experiment Station Bulletin 721, 

est Longitude): U.S. Geological Survey Miscellaneous 

°

, quantit

,

Open-File Map 84-689, sheet 2, scale 1:100,000.

-Supply Paper 1576-

Be

A.

, M.S. thesis, 175 p.

aylo

r

Agriculture, Bureau of Chemistry and Soils, se

., Ker

, K.

., 1984, Buried or abandoned drainage in the Havre 30' x 

Colton, R.B.,

arnes, H.D., 1964, Geology of the Fort Peck area, Garfield, McCone, 

quadrangle, Bearpaw Mountains, Blaine Count

W

V

of the Shambo quadrangle, Bearpaw Mountains, Hill and Blaine Counties, 

W

,

.M.,

Mickelson, D.M., Clayton, Lee, Fullerton, D.S., and Borns, H.

r

-Resources Investigations Report 92-4163, 41 p.

quadrangle, Bearpaw Mountains, Blaine Count

v

y

pre-Illinoian Havre till, likely produced by slump or collapse of stream 

W

r .L., eds., Quaternary 

.A., 1957, Geology and ground-water resources of the Lower Marias 

, Part 2, North

Colluvium, for purposes of this map, is material that was transported and deposited by slow

Solle

. 18, 

W

 quadrangle, United States and 

bedrock in the Havre 30' x 60' quadrangle, Montana: U.S. Geological Survey 

Society of v

North Dakota, U.S.A., in Ehlers, Jue

y

T

Montana: Montana Bureau of Mines and Geology Open-file Report MBMG 439, 9 

and temporal relations of mountain and continental glaciations on the Northern 

.

T

r

Hearn, B.C., J

r

r

V

.,

De

Knechtel, M.M., 1942, Snake Butte boulder train and related glacial phenomena, 

y

.

ipton, M.J., and Lindvall, R.M., 1965, Quaternary geology 

, D. P

Bulletin 1081-C, p. 91–

T

r

1

Thickness 1–>20 m

., J

Disintegration residuum, for purposes of this map, is material that was derived primarily from

, 

deposits in the United States east of the Rocky Mountains: U.S. Geological Survey 

W

Fullerton, D.S., and Colton, R.B., 1986, Stratigraphy and correlation of the glacial 

T

., 1896, Geology of the Little Rocky Mountains: Journal of 

., 1987, Quaternary and

, Montana: U.S. Geological Survey 

r

Giesecke

aquifers as a possible source of water in a portion of the Montana Great Plains: 

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., and Colton, R.B., 1984, Buried or abandoned drainage in the Harlem 30' x 

Patton,

y

F

., and Ehle

, 

itkind, I.J., and Stewart, D.B., 1957, Preliminary geologic map of the 

oung,

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W

isconsin glacial record of the Laurentide ice sheet in the United States, in Porte

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W

Calhoun, 

adjacent areas: Canadian Journal of Earth Sciences, 

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. The basal nonglacial gravel beneath 

., 1932, Soil survey of the Milk River 

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TERNA

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Where residuum is thin, pedogenic soils may extend through the residuum to or into

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r

, 

W

gen, and Gibbard, 

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T

F

W

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1

T

r

Schmidt, R.G., Pecora,

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., and Fre

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r

-Resources Investigations Report 92-4162, 86 p.

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W

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r

 BEDROCK—Includes some badland terrain

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r

eseth, Roge f

, B.

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.

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urne

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., and Sholes, M.A., 2003, Geologic and structure contour 

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,

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.

oungs, 

W

f

., and Christensen, 

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W

Christiansen, E.A., 1979,

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., and Hearn, B.C., J

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, Montana: U.S. Geological Survey Miscellaneous Geologic Investigations 

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Quaternary geologic map of the Regina 4

W

y

Alden,

y

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y

T

Be

(reconnaissance) of the Northern Plains of Montana: U.S. Department of 

T

r

W

V

.C., 1964, Geology of the Rattlesnake 

., Stewart, D.B., and Dixon, H.R., 1957, Preliminary geologic map 

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W

15–27.

., and Hunte

r

., 1960, Geology of the Maddux 

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F

y

2

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°

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., 2004b, Map showing spatial 

, O.J., 1962, Drainage and domestic wate

. 1929, no, 21, 74 p.

, J.H., Brace,

., and Hearn, B.C., J

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T

Open-File Report 89-171, 13 p.

I-236, scale 1:31,680.

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T

T

., 1983,

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r

, Montana: U.S. Geological Survey 

The

Collie

Bulletin 

T

by H.A. Swenson]: U.S. Geological Survey

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3

, D.R., 1993, Preliminary map showing the thickness and character of Quaternary 

r

.

(NM-13), 37 p., map scale 1:1,000,000.

V

Patton,

America Bulletin, 

Alden,

Zimmerman, E.A., 1960, Preliminary report on the geology and ground-water resources 

W

y

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Be

., and Colton, R.B., 1986, Identification of glaciofluvial and buried preglacial 

no. 5, p. 347.

W

investigations in the Milk River Unit, Blaine Count

., Pecora,

.

Boy 30' x 60' quadrangle, north-central Montana: Montana Bureau of Mines and 

T

F

W

Y

v

W

Patton,

., Christensen, 

potential for additional ground-water withdrawals along the north flank of the Little 

16.

isconsinan deglaciation of southern Saskatchewan and 

STRATIGRAPHIC SECTIONS, #1) . 

W

P

A

r

., 1918,

ate

appreciable lateral transport. It is an earth material, not sediment or a deposit.

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Feltis, R.D., 1983, Ground-water resources of the Fort Belknap Indian Reservation, 

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y

.

r

.C., 1932, Physiography and glacial geology of eastern Montana and adjacent 

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T

1

, L.

., and Lindvall, R.M., 1961, Glacial map of Montana east of 

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T

Survey Open-File Report 63-50, 

.

1957, Preliminary geologic map of the

,

Ker

Miscellaneous Geologic Investigations Map I-234, scale 1:31,680.

W

Geological Survey Oil and Gas Investigations Map OM-4, scale 1:48,000.

r

, 

Bria

r

.H.H., 1906,

y

. 16, p. 913–938.

vertebrate (ungulate) fossils. 

Collie

Y

Open-file Report MBMG 467, 8 p. map scale 1:100,000.

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ma

V

SOURCES OF INFORM

r

the glaciated United States east of the Rocky Mountains-Northern Plains states 

Reviews, 

. 4, p. 399–428.

 A

y

Montana: U.S. Geological Survey

America: r

T

W

Pecora,

Colton, R.B., and Patton,

Jensen, 

y

arrick quadrangle, Bearpaw Mountains, 

.C., 1982, Geologic map of the Glasgow 1

W

Y

Lemke, R.

, D.G., eds.,

Montagne, Cli

W .K., 1993, Lithologic logs of observation wells and test 

Survey Professional Paper 50, 62 p.

W

T

are chiefly silt and fine sand with scattered granules and pebbles; generally 

Dyke,

y

Sheetwash alluvium, for purposes of this map, is material that was transported and deposited

., Brownfield, S.H., Richardson, R.E., and Nielsen, G.A., 

, and Montagne, Cli

soils: Montana

., Colton, R.B., and Clayton, Lee, 2007, 

., 1984a, Selected well data including water qualit

TION

Calgar

, and depth to 

ate F

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., and Manifold, C.B., 1933, Soil survey 

.

.

W

Pecora,

30' quadrangle,

T

., Bryant, Bruce, and Ernst,

.O., and Glasse

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W

Geological Survey ate

T

paleosol in the lower unit of Havre till; glacial lake deposits; and nonglacial 

., 1964, Geology of the Cleveland 

-grained near the base. Minor silt and clay beds; local gravel channel 

Thom,

American deglaciation with emphasis on central 

Swenson, 

, chiefly sheet flow and rill wash.

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1

 x 6

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y

W

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Patton,

r

W

Patton,

r

gantino, R.N., Porte

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60' quadrangle, Montana: U.S. Geological Survey Open-File Map 84-688, sheet 1, 

and

.

alley and McCone Counties, Montana: U.S. Geological Survey 

Montana: U.S. Geological Survey Miscellaneous Geologic Investigations Map 

.G., 1961, Geology of the Lloyd 

W

, H.E., 1982, 

Bria

y

. 1, p. 55–82.

, Montana: U.S. Geological Survey 

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.

gen, and Gibbard, 

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Irrigation Project, Montana [with a section on chemical quality of the ground water

mass-movement processes, chiefly creep.

r

eed,

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W

Open-File Map 84-698, sheet 2, scale 1:100,000.

. 35, p. 385–423.

, M.Sc. thesis, 205 p.

.

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.

-supply 

r

W

., 2002, Geologic map of the Rocky 

, S.

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W

,

141-

PRE-QU

r

W

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in-place mechanical disaggregation of clastic bedrock or other materials, with no

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.H., and Pirsson, L.

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., Engstrom, D.B., and Dixon, H.R., 1957, Preliminary 

Geolog

T

W

P

Bulletin 

gantino, R.N., Patton,

r

Montana

W

60' quadrangle, Montana: U.S. Geological Survey Open-File Map 84-689, sheet 1, 

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W

., Stewart, D.B., Engstrom, D.B., and Dixon, H.R., 

r

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right, H.E., J

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F

of northern Blaine Count

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Schmidt, R.G., Pecora,

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area, Montana: U.S. Department of

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Sholes, M.A., and Be

R

quadrangle, north-central Montana: Montana Bureau of Mines and Geology 

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v

., 1984b, Selected well data including water qualit

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.

., Morris, E.R., Strahorn,

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12 p.

., and Swadle

W

W

, J.H., Pecora,

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y

Pleistocene: Minneapolis, University of Minnesota Press, p. 3–37.

, D. P

Bryant, Bruce, Schmidt, R.G., and Pecora,

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Colton, 1986). 

.

The thick alluvial and lake deposits of the fill 

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,

Count

1

W

gin in Montana: Geological Society of

r ford, 1980, Geologic parent materials of Montana 

°

T

W

. 5, p. 69–82.

A

ild, James R., 2003,

y

Amsterdam, Elsevie

W

p. 131–150.

r

T

.B., and

map of the Harlem 30' x 60' quadrangle, north-central Montana: Montana Bureau 

T

W

T

.S., and

I-237, scale 1:31,680.

 x 

.

T

F

., Laird,

The 

ford, Munn, L.C., Nielsen, G.A., Rogers, J.

Mountains, Fort Belknap Indian Reservation, north-central Montana: U.S. 

W

.

Havre till of Fullerton and Colton, 1986); lake and fluvial deposits; a 

middle North

r

r

A.S., 2004,

LIS MAF O UNITS T P

CORREL MA A FTION O UNITS P

EXPLAN MAF ATION O SYMBOLS P

ALLUVIAL-FAN DEPOSITS

FLOOD-PLAIN AND CHANNE L ALLUVIUM

FLOOD-PLAIN AND CHANNE L ALLUVIUM AND LAKE DEPOSITS

LAKE CL AND SI A L Y T

LAKE CL L AND GR A T Y, SI , SAND, VE A L

LAKE AND EOLIAN SAND T AND SI L

WASH AND

 DEPOSITS

ALLUVIUM, LAKE DEPOSITS,

L

COLLUVIUM, SHEET 

GLACIOFLUVIA

COLLUVIUM, SHEETW ASH ALLUVIUM, AND LANDSLIDE DEPOSITS

YLOAM COLLUVIUM

LOAMY COLLUVIUM

SHEET ALLUVIUM

AYE Y COLLUVIUM, DISINTEGR AND

ASH

CL OR LOAM TION RESIDUUM,

W

Y A

LAKE CL L AND GR A T Y , SAND, VE , SI A L

Ground-moraine deposits 

End-moraine deposits 

Stagnation-moraine deposits

KAME-MORAINE DEPOSITS

ICE-CON SAND T AC AND GR T AVEL

OUTWASH SAND VE AND GR A L

FLOOD DEPOSITS 

PEDIMEN ALLUVIAL- AND FLUVIAL-TERRACE DEPOSITS T, FAN,

Ground-moraine deposits

End-moraine deposits 

ALLUVIUM AND LACUSTRINE-FILL DEPOSITS

BEDROCK

Contact

rSho eline

r isconsin Glacial Readvance,

T

isconsin Glaciation, o W

 position of a significant stillstand of an ice margin—

 W

r

 the advance

Limit of Late limit of a Late

 o icks are on the side of

Limit of an Illinoian Glacial Readvance on the boundary Plateau—Dashed where

 inferred; ticks are on the side of the advance

 

T

r

 Mountains and Bearpaw Mountains—

ed f esidual

om the Canadian Shield on the north flanks of the Little Rocky

r r

r

icks are on the side of the advance 

Limit of Illinoian Glaciation infer om the distribution of isolated 

 erratic boulders f

Boulder train from a source igneous intrusion. Intrusion is mapped as 

g. Snake Butte boulder train is modified from Knechtel (1942); smaller 

 Snake Butte boulder train are the limits of glacially-transported boulders observed

Dispersal fan—

 unit cr

 boulder train farther west is from Schmidt and others (1961, 1964). Boundaries of

 by the authors 

Location of important stratigraphic section (see IMPORTANT STRATIGRAPHIC SECTIONS)

PRE-QU YRTERNAA

2

HOLOCENE TEAAND L WISCONSIN

HOLOCENE, LATE PLEIS AND MIDDLE PLEIS TOCENE, TOCENE

SLUMP-BLOCK LANDSLIDE DEPOSITS AND ROCKSLIDE DEPOSITS

HOLOCENE AND PLEISTOCENE

PLEIS OCENET

afj

crg

cax

jea

lx

tlx(e)

R

tlx(s)

ke

kg

gg

aqa

pgd

tks(e)

asr

tks

tlx

cly

afj

al

alt

lca

lu

lse

cad

caa

crg

cly

cax

jea

lx

tlx

tlx(e)

tlx(s)

ke

kg

gg

aqa

pgd

tks

tks(e)

asr

IT

R

al

alt

lca

lu

lse

cad

caa

TEAL WISCONSIN

TIL YLOAM L

PLEIS AND PLIOCENE OCENET

ILLINOIAN

LOAMY OR SAND Y TIL LOAM L Y

MIDDLE PLEIS OCENET

Attributed to late Pliocene continental glaciation

Erratic bed

 Shield (Knechtel, 1942)—

rom the Canadian

 (Fullerton and others, 2004b)

rock block in the Bearpaw Mountains, derived f

r Bedrock and

 or (3) deformed masses of bedrock and surficial deposits characterized by overturned

Thickness 5–>30 m

Known o glaciotectonic terrain—

 slices of bedrock, till, and stratified sediments that form parallel or concentric ridges;

r

 tilted bedrock blocks overlying till and stratified sediments; (2) stacked or imbricated

 deposited by overriding ice. 

 suspected glaciotectonic deposits o

 surficial deposits that were thrust, stacked, and deformed by glacial ice. Chiefly (1)

 folds. Some glaciatectonically transported materials are covered by till that was

W

 meltwater floods, not by glacial ice

 moraines—

r isconsin age typically is 2–10 m.

 that landforms in the southeast corner of quadrangle were formed by subglacial

r

W

 moraines," "ice-crack moraines," and "corrugated moraines." 

Mino

 vanished ice ma

 high. Includes "transverse ridges," "small moraines," "washboard moraines," "annual

ild (2003) proposed

Mainly till. Most of the ridges delineate the configurations of 

gins. Local relief of ridges of late

 Concentric gravelly moraines of Illinoian age on the Boundary Plateau are 1–>9 m

 ice-scou

 axis of symbol is parallel to the direction of ice movement. Some symbols represent

ild (2003) proposed that linear landforms in the southeast

r Linear drumlin, rock drumlin, or fluting. Long

W

Ice-molded o ed landform— r

 more than one landform. 

 corner of the quadrangle were formed by subglacial meltwater floods, not by glacial ice

ection of ice movement indicated by striations on bed

 center of arrow shaft

Dir ock—r Measurement at

Esker—Subglacial or englacial stream deposit

ock valley of the ancestral Missouri River—From the west edge of the

1 km west of Chinook. 

 termination of the buried valley

r

1

 River occupies the valley of the ancestral Missouri River eastward from the

Buried bed

 map northeast through Havre, to about The modern Milk

tsaE

kroF

keer C enya W

Lo eek Cr an g

reek

C

ek re C men Gor

ild Horse

Reservoir

W

Reservoir

Weigand

Horse Shoe

Lake

Silverbow Lake

Point of Rocks

Reservoir

Cook Reservoir

Bowes Lake

Martin Lake

Lake Thibadeau

North Chinoak

Reservoir

renMcLa

Reservoir

Reservoir

Hay Coulee

eedmanC

Reservoir

r

ild Horse

Lake

W

Reservoir

McLean

Mud Lake

Tule Lake

Reservoir

reemileTh

Putnam

Lake

r i

C

W e m

g

r a k

B

e

e r i C

W e m

g r a k

B

L a t e i r C l e W

m t r e k

H e

W s d

C o e

i e r r k

l

N o t r u k o r h e F

d r k C M e

e d r M

k e u C

l s

r l

W

k k t

e A i C

e a e

e

d

C

M

e r u

k

p e e l C e o es r P

k o D

h a

s l u o n

o S t C

d a

n

l R e

M k

i r

i

v

o e d

C n e

D s r k o

e k C i e r l

k

M

i e b r s i

k n a e s n i

C

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Dodson

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Hogeland

Fort Belknap

Havre

Turner

Harlem

5 0 5 10 15 MILES

SCALE 1: 250 000

5 0 5 10 15 20 KILOMETERS

QUATERNARY GEOLOGIC MAP OF THE HAVRE 1° X 2° QUADRANGLE, MONTANA

By

David S. Fullerton, Roger B. Colton, and Charles A. Bush

2012

108°00'

48°00'

te 

Tra

B

i

o

n

ulder

 

Snake 

 

 But

110°00'

Geology compiled in 1976–86, 1990–2002, 2004–2008

Edit and digital layout by Jeffery R. Hartley 

Geology digitized by Charles A. Bush

Digital cartography by Charles A. Bush

Published by U.S.G.S. Science Publishing Network Denver

Manuscript approved for publication February 5, 2012

49°00'

1970 MAGNETIC DECLINATION FROM TRUE NORTH VARIES FROM 181⁄2° EASTERLY FOR 

THE CENTER OF THE WEST EDGE TO 171⁄2° EASTERLY FOR THE CENTER OF THE EAST EDGE

49°00'

108°00'

S

W M O U

B

N

E

T

A

A

R

I

P

N

A

 LITTLE

ROCKY MOUNTAINS

BOUNDARY PLATEAU 

http://nris.mt.gov)

TRANSVERSE MERCATOR PROJECTION

1927 North American Datum

Base hydrology from U.S.G.S., 1974

Base topography from National Elevation Dataset (NED), U.S.G.S. (http://seamless.usgs.gov)

Base cities, roads, and railroads from Montana State Library (

48°00'

110°00'

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

imply endorsement by the U.S. Government

This map was printed on an electronic plotter directly from digital files. Dimensional calibration may vary

between electronic plotters and between X and Y directions on the same plotter, and paper may change

size due to atmospheric conditions; therefore, scale and proportions may not be true on plots of this map.

For sale by U.S. Geological Survey, Information Services, Box 25286, Federal Center, Denver, CO 80225,

1–888–ASK–USGS

Digital files available at http://pubs.usgs.gov/of/2012/1028

Suggested Citation: Fullerton, D.S., Colton, R.B., and Bush, C.A., 2011, Quaternary Geologic Map of the

Havre 1 x 2 Quadrangle, Montana: U.S. Geological Survey Open File Report 2011-1028, scale 1:250,000 

[http://pubs.usgs.gov/of/2012/1028]. 

ArcInfo coverage and a PDF for this map are available at http://pubs.usgs.gov/of/2012/1028

U.S. Department of the Interior

U.S. Geological Survey

Prepared in cooperation with the

Montana Bureau of Mines and Geology

OPEN-FILE REPORT 2012-1028

Version 1.0

SHELBY LOBE

W

 LOBE

WHITE TERA

LOMA SUBLOBE

 LOBE

YELLOWSTONE

MISSOURI V

 LOBE 

 GLASGOW OR

ALLEY

Pincher

Brocket

Fort Macleod

MonarchKipp

Lethbridge

aberT

Drywood

Waterton Park

iewVMountain 

Cardston

Kimball

Raley Spring Coulee

Magrath Raymond

Del Bonita win RiverT

Milk River

Bow Island

Robinson

Foremost Etzikom Pakowki

Pinhorn

Comrey

Kincorth Maple Creek

Battle Creek

Willow Creek

Rangeview

Divide

Eastend

Ravenscrag

Climax

Shaunavon

Neville

Kincaid

Val Marie

Orkney

Rosefield

Reliance Summercove

Lafleche

Ettington

Killdeer

eyburnW

Ratcliffe

Ardill Galilee

Crane alleyV

Dummer Yellow Grass

Vwin T alley

iceroyV

Bengough

Hardy Radville

Coronach Big Beaver

Big Muddy

Lake Alma

Osage

Stoughton

orquayT Outram Estevan

Frobisher

Crosby

Fortuna

Bowbells

Alamo

Lostwood

White Earth

Ray

Williston

Grenora

Flaxville Plentywood

Scobey Peerless

Medicine Lake

Brockton Culbertson

Poplar

Frazer Wolf Point

Whitewater

Hinsdale

Bowdoin

Malta

Glasgow

Fort Peck

Turner

Chinook

Havre Harlem

Dodson

Box Elder

Rocky Boy

Lodge Pole

Sunburst

Shelby Chester

Conrad Big Sandy

Babb

Cut Bank Browning

West Glacier

East Glacier Park

alierV

Pendroy

Hall Coulee

Marias Pass

Bynum

Choteau

Augusta

Fort Benton

Power

Portage

Great Falls

Cascade

Eagleton

Landusky

Iliad

Denton Roy alentineV

Lewistown

Sun Prairie

Jordan

Sidney

Richey

Circle

Intake

Glendive

Keene

Cartwright atford CityW

Grassy Butte Dunn Center

alleyVGolden 

Opheim

MOUN AIN T ALLEY AND PIEDMONT GLACI V ATION

PT Pinedale till

LAURENTIDE CONTINEN AAL GLACIT TION

Illinoian till

Isolated and scattered exposures of

 pre-Wisconsin till and glacial erratic boulders

 of Bearpaw Mountains

Pre-Illinoian till on north margin 

Scattered glacial erratic boulders, no till

Not glaciated

W L Late Wisconsin till

IL

PW

PI

GB

Pre-Wisconsin

 erratic boulders (limit of PW). T

 as far south as the limit of boulders

Limit of pre-Wisconsin till and glacial 

ill is not present

Illinoian

 and (or) surface morphology 

Limit of Illinoian glaciation (IL), defined by stratigraphy 

LAURENTIDE CONTINEN A AL GLACIT TION

Late Wisconsin

 morphology 

L

 defined by stratigraphy and (or) surface 

Limit of late Wisconsin glaciation ( W),

 defined by stratigraphy and surface morpholog

 Hachures on the "up-glacier" side of limit

 by reorganization of glacial dispersal centers; 

.

Limit of a regional glacial readvance caused 

y

Limit of "C2" glacial readvance in southwestern Alberta

IL

d h i r

u t R e

J i v

W L

IL

IL

M s r v s u i r i o i R e

IL 

WL

Teton Riv er

PW

M i

i r r s R e a a v

Reservoir

Fresno

PI

i i r M k R e l v

PT

PT

e e e P l t s u e a s a P r l

o a v P

l i r

p r R e

PT

o t i

o

y M n

R

s k u a n c 

WL

r k

C n C t a e

u B k e AEXPLAN TION

Frances

Lake

Tiber Reservoir

Fort

Reservoir

Peck

Glacier

Park

National

Highwood

Mountains

Mountains

Bearpaw

Little Rocky Mts

Cypress

l siH l 

Figure 1. Regional ice flow during maximum

 late Wisconsin glaciation.

Willo n w u h B c Lake

M e s L u t v o t i e i i r s i r l R

W b ny re u 

v u e h l i M r s s l R e s l e

102°

a i r S n M y R e i r v a t

Mountains

Killdeer

Plateau

Boundary

O m i r d n R e l a v

104° 106°

rRive , stream, and modern lake shoreline

t i r

a r n R e W e o v t

108° 110° 112°

d i r n R e

l a O

v 

m

Pre-Illinoian Pleistocene

114°

v i i r M k R e l

 north flank of Bearpaw Mountains

 pre-Illinoian Pleistocene till (limit of PI) on

Southern limit of known surface exposures of 

50°

Limit of glacial erratic boulders on bedrock

 erosion surfaces (limit of GB)

49°

Glacial lakes Great Falls and Musselshell. 

 Full extent of lakes not shown

48° Williston

 

47°

Shelby

Glasgow

Cut Bank

l d eG n v e i

Choteau

Two Medicine

 lobe

Wood u a M n i o t n 

Lewistown

(792 m; 2,600 ft) confluent

glacial Lake Musselshell

Late Wisconsin phase of

with glacial Lake Jordan

Jordan

Late Wisconsin

(792 m; 2,600 ft)

Lake Jordan

phase of glacial

F e s r o o m t

atford CityW

Great F l al s

Lethbridge

of glacial Lake Great Falls

Late Wisconsin phase

(1142 m; 3,715 ft)

C2

Cypress Lake

A E AB TL R 

a l w t r s i

S

s e G s H l e

olf PointW

CANADA

T E N A A H A S K C W S

C2

Havre

UNITED STATES

 Upland

Wood Mountain

IL

W L

N N O A M T A

U

M S

R

 O A

S

U C 

E

 I O

 I T

IL

WL

H A T N T D O R K A O

N K TAT A OR D O H

IL

IL S K C W A A H A S T E N

IL

LW

O A M T AN N

GB

w o e r o t e i Y e l s n R v l

B TL R A E A

IL 

u v i o i i r

M s r R e s

 Plain

Flaxville 

Location of Havre quadrangle

IL

WL

IL 

i R

M s r v r s u i e i o

Generalized direction of ice flow

WL

25 25 50 75 100 KILOMETERS

SCALE 1:2,000,000

0

25 0 25 50 75 100 MILES

Lake Sakakawea

TLMA A SUBLOBE

AH VRE LOBE

Waterton Lakes

National Park

Hills Porcupine

v e y i r B l R e l