pretation

Map Palaeozoic

about two

*Most

zoic

basement The

Elk

listed

I

on

Manitoba, maps*

Selected

have

area sippian

suiting lows, part,

nian ticular,

ments result

directly

formations

uplift

sitional

during

malous undergone

time, During

had

some

the

giving

Saskatchewan

within

nor

ment tures

— indicates modified

maps Winnipeg,

MonitGba Geocgist,

H.

Some

The

the

Natural

the

tailed

HIS

Palaeozoic Point

Series,

regional

Superior

and

provinces,

a

been

R.

Prairie

to

20

structural the feature

and

of at

extent

related of of

of

for

slightly

the study

northeastern from

the

Williston

periods

relative

rise

periods

and

oil

prominent

or

references

McCabe

salt

study

per

these

of salt

reflect the

the

the

to

Manitoba

Cenozoic

that

important

truncation

Palaeozoic

Dept.

tectonic

a

as

series

Superior

all

in

Man.

prominent

issued indirectly

Resources,

accumulation

erosional

the

a

relatively to

salt

Evaporite

in

of

is

solution. Palaeozoic

Precambrian

cent

structure

solution

crustal

end.

to

southwestern

well

Palaeozoic

considerable

which

the

border.

maps

tectonic of

different

of

to the

is

both

of

later

a

tectonic

highs

not

Precambrian

Basin

solution,

deposition,

by

detailed

of

Palaeozoic

the

based

erosbrn

Mhies

of

principal

Southwestern

break

to

activity

as

portion

crustal

subsidence.

in

only

have

Introduction coincides

block,

the

by

are patterns

basin

edge

Palaeozoic

hinge

sedimentary

the

the

isopach

and

regional

higher

Numerous

and

East-west-trending

modifying

all

mid

salt

ABSTRACT

contours

elements

strata

relatively

response and

framework

on

Mines

between

the

in

included

occurred.

regional

Annual

present

formations

occur

differential

relatively

series

basement.

available

block

of extent

of

Elk

Manitoba

isopach

line

;

subsidence

as

basin

Palaeozoic

the

the

especially

structures

rate

this

composite

basement

roughly

for

the

both

a

basin

of

and

Point

Branch.

at

along

movements.

of

may

examination

Daly-Virden whole,

For

and

other the

most

but

on

southwestern

of

Manitoba may to

by

basin

makes

Transactions,

in the

structure

minor

As

geologic

basins

Western

structure

thicks,

the

structure

greater

framework.

subsidence,

difficult.

The

geophysical

the

are

the

Churchill

Basin

major

the

also

controlling

compaction

with

also

the

of a

edge

Manitoba,

during

and

of

be

features.

tectonic

probably

small

effect

appears

result,

appears

Williston

somewhat

tectonic

tectonic

southwestern

Precamhan

direct principal

Stratigraphic

the

be

salt

orogenic

due,

the

(Figure

later

probably of

—

basin

setting

tectonic

In

amounts

is

reflected

and

is

Ordovician

Palaeozoic Meeting,

producing

structural

the

Manitoba-

of

have

and

of

edge

the

contour

Manitoba

in

located

addition,

due

elements

whereas

to

to

In

are

Meso Missis

inter-

isopach

these caused

forces,

a

move- Volume

data.

De.vo uplift.

only

large

depo

Supe

and

base-

have

have

par- belts

ano

are

1).

been

and

de

fea

to

—1— the

re

of

to CIM,

‘

possible

sin the

have

nic

differ

block.

Precambrian

is basins

The

along

2.

high

the

Shield provinces.

zone

have

tonic

nent Precambrian rectly

area

er that

Elk

features maps

that be

Tectonic

LXX,

As

Although

Palaeozoic

A

underlain

forces

uplift.

believes

grain

rather

Point

Palaeozoic

Manitoba

had

between

the

the

within

and Calgary,

there

prominent

basement

this

had

considerably

framework

for

area,

affected

is

that

I

1967,

throughout

Churchill

Manitoba

and

a

giving

thus

low

break

basins

the

the

This

uniform,

that

are

somewhat

these

the

and

the

principaily

Superior

the

basement

even

gravity

portion

pp.

greatest

underlain

October,

cover

various

feature

by

a

in

over-all

rise

regional

the

magnetic

its

appears

zone

Churchill

two

%

considerable

is

180-189

the

and

in

in

portion

major

southwestward

tectonic

to

the

an

the

average

age,

is

major

anomalies,

of

different

is

southern

Framework

block,

both

Superior

effect

(Figure

and

Palaeozoic

structural

stratigraphic

to

indicated

examination

the

by

principally

basin

1966

fairly

discontinuity

in

lithologic structural

low

and

of

have

basin

Precambrian

the

rocks Williston

framework

Formations

whereas

crustal

both

on

T

is

Superior

number

framework.

part

tectonic

well 2)

Manitoba

formed

blocks

one

as

O

the

subsidence

also

.

pattern

by

extension

formations

of

the

shown

The

character,

of

by

that

features

thickness,

defined

Palaeozoic

of

succession,

and the

the

seen

Saskatchewan

are the

Williston

of

an

rocks

or

Precambrian

has

response

most

the

blocks

appears

Elk

appears

associated

anomalous

map-area.

in

anomalous

known

The

Churchill

boundary

to

and

been

beneath

Figure

isopach

of

in

promi

of

tecto

Point

shows

occur

may

writ-

it

ba

the tec

and

and

the

the

to of

to

di-

is

to to

‘

post-Palaeozoic

that

ing

has, now

gently lain a where

dence. strata zoic between sequently has extensive gave

inces and Lake

as

throughout

ure of is material

Precambrian billion

ure strata and

because for younger they

gave

stones looking little

topographic prominent tion,

where Lake this though

formation. relief face.

control

superimposed less perficial prominent

southwest,

differential

but re

sents

evaluating

(Figure

zone

The

Another

the

The

A

a

this

belts

located

affected

these

is

Silurian

by

need

outcrop

cover. show not

prominent

the

in

rather

may map

Winnipeg. further

any

an

a

St.

or

Available

and

northeast-trending

a

this

in

Precambrian

must

but

was

seen years.

granitic

of

of

to

UP

make

feature most

structure

normal

turn,

the

of

and

major

formed

Churchill-Superior

age

activity.

no

used,

erosion

Martin,

excess

to

post-Palaeozoic structures

Palaeozoic

)

(Figure post-Precambrian

in possibly

on

the

volcanics,

is

the

to

prominent

boundary

with

superficial

structures.

The

the

the

This

the

immediately

ranging

Ordovician

uplifted

Churchill to

pinch

be

are

or

associated

high

post-Middle the

compaction.

the

strata,

not

4,000

of

and

the

shows

of

it

Assuming

age,

Superior

undergone

dip

these

southwest.

be

subcrop

crystalline

problem

checked.

pattei’n

tectonic

bend

volcanic

and

tectonic

This

“Superior”

difficult

cannot

only

this

of data

is

as

the

youngest

structure

the

at

west

pronounced

very

so

Two

on

coincident map

8)

out

represent

coupled

feet

it

the

700

a

of

volcanic

as

from

tectonic

by

and

a

all

Precambrian

in

and

pronounced

. zone

results

reflects result

that

Palaeozoic

trace

200-250

the

feature

and

result

indicate

must

or

The The

southwestern against

of

important

shown radioactive

time,

relatively

most

in

post-Precambrian

the

of

province,

of

be

framework

feet,

northwest the

rocks,

on

similar

in

The

that

framework,

to

sedimentary

true

Silurian.

erosion Moose

Differentiation

partially the

post-Middle erosion

extends Superior

a

and

Pa.laeozoic

17

strata

map,

Tnis

the

principal

subsidence,

the

with

Palaeozoic

determined

outcrop

of

delineate

the

age

series

boundary of

tectonic

K-Ar

have

of

may

late rocks

and features

associated

direct

post-Palaeozoic

with

and

the

on

Lake

to

million

in high

tectonic

however,

the

vesicular

the

that

map-area.

Palaeozoic

either

basement

but

Lake

to

the

wedge

of

Precambrian

flexure 50

Figure

the

Precambrian

in all

in

basement factor

which

be

surface

uniform

that

beneath remained

of

whole-rock

of

are

high.

The

the age

Winnipeg

Precambrian

truncated

gravity

the

belt

is

in

approximately

evidence

the

the

this feet

Precambrian

this

of

Manitoba

feature

totally

movement.

is

northwest-trend-

any

sparse

the

strata

structures

syncline years.

should

zone

the

erosion

Jurassic

salt

exposed

the

there

boundary

structures

the

determinations

and

except

synclinal

relatively

typical

markedly

granitic

are

area

of

of

to

3.

also

nature

suggests

area,

per

north

feature

but

deformation,

with

between

tectonic

existence

the

formations

Because

Ordovician

Ordovician

consider

vicinity

dip

collapse

represents

Palaeozoic

high

very

hence

which

anomalies

unreliable

emergent deep

However,

shown

shows

neverthe

available

has

deforma mile.

and

the

narrows,

by

method,

the

surface is or

Palaeo

or

that

surface

at

a

end

to

green-

of

subsi

which

prov

rocks

over- fresh

is

flex-

flex-

most

zone

been

map even high

local

pre con-

that

is

sur

well

dif

pre

age

the

dip

the

the

2.4

de

Al-

su

up

by

of

of of

—

of

it

or

of

in

a 2

-—

feature.

between though in to

helped with

crop subsidence southwaru area slight which the

dolomitic occurred shows if high

during by of The nipeg.

rallel of the

occurs limited

if

unit trend

units

Superior

dary ton with

western surface, cates

relatively

ba of gional ing

at

tcLl

uniform eozoic Manitoba

ince area

tours

by tigraphic pronounced

subsidence such in are

structural each ferent,

.

Also

The

Although

Ordovician

Most

the

this

the

shale.

not

this

the

portion

southwestern

a

the

marker

basal

isopachs

Ordovician

Basin,

seen

occurred

easterly

of

within

where

belt.

sand

the

in

zone, surprisingly

of

the

facies

can

deposition

units

tectonic

shows

of

isopach on

differential as

an

to

sedimentation

Differential legend.

sand all

Red

Williston

area

Winnipeg

worth

approximately

no

time,

with

the

Precambrian

of

these

the

with

Manitoba

to

during

The

localize

an

province.

trend and

Ordovician the

isopach

the

greater

be

limestone. anomalously

The

succession

are

content

thickening

of

however,

deformation.

magnetic

of

the

and

and

horizons, be

Cambrian

River the

extreme

and

the

structural

reflects

as east-trending

of

change

rapid

isopach

body

trend

the

attributed

and along

strata

the

orogenic

the

Palaeozoic

thickest

units

differential

rather

of

noting

para-time-stratigraphic

movement,

The discordant

isopach

the

Palaeozoic

isopach

well

of

the

Winnipeg

tectonic

Total

Red

on

the

the

result

deposition

Manitoba

thickening. Basin

amount

thick.

basin.

the

isopach

few

time.

the

has lateral

is

compaction

of constituent

is

structure

an

isopach will

was

compaction

as a

comprise

from

southwestern

trend

Red

the

Winnipeg

River

data

Ordoviciai

This

coincident and

and

structure

of

the

in

rapid

markedly

is pattern

by

strata

structure

Precambrian

Ordovicisn

very

thickness

rise

given

and

thin east-trending

trend

the

belts

(Figure that

to

the

be

It The

the

trends.

Manitoha

differentiation

the

the

erosion

relative

River

lithologic

to

of

Carman

as

conseçuently

formalion

is formations

bar-dike

are

subidence

dolonilte

anona1ies

to

and

differential

stractural

most

suggests

time. is

discassed

appears

smooth,

of

trends

Red

area principal

the

thi±ening

subsidence

the

the

may

evidenced within

area

rise

Churchill-Superior

This an

pronounced

is

th

the

‘possible,

f

of

the

available

anits

formation

formation

the

4)

discordant contours

present

seen

around variations.

River

with

The

utcrop-subcrop

contours, Carman

persistent

subsidence surface,

the

The

northwest.

to isopach

coincident first

be

isopach

amount

of

Sand

corner

indicates

body

Carman

except

changes

are

shows

trend

orogenic

to

are

the

to

flat

the

thickening

present. names

axis.

Winnipeg

relatively

briefly.

shown

to

tectonic

isopach

relatively

high of

apparently

a

is

units

record

by

limestone

the

however, compaction in

result

similar

south

is

to

not,

structure

isopach

to

be

of

this

Precambrian

Precambrian

southwestern

accompanied

Precambrian

Sand,

of

patterns

discordance

reflect

the

(Figure

of

is

and

the

for

a

seen

(Figure The

of

sand

may

the

from

associated

determine to

isopach

the

almost

that sandstone

This

are

the

and

with relatively

in

by

The

belts,

delimited

uniform,

the

area

The

of

of

Manito

element

tectonic

flexure

from

pattern

a

the

show

Willis-

shales

to

to

which

south-

south,

basin

rapid

rapid

boun

body. is

these

Prov

thick

Win-

noted

most.

Pala

most

small

have

sand

mdi-

that

stra

out-

belts

hay-

true

and

con-

the

pa-

the

5),

To-

de

al

for

re

6)

at

of

of

of

a a —3—

‘-

-r----A-1

-at 4 : ,..

t - -

— :-

— - _ — --

sjiI’%i ,

- .

--—I . -

-

—

j\\

dOr . - r

--

o

Y

f :

:,

‘

__Th—

>- \J\

I

t

:l j

-

Th

----r

C

/

- \:-

_:————

\

\) -- .:.

\I c • • >

_ ?

j \ .

- I I

It

? \. -

_ i. —

— rz Os’j _ :‘::. J

c’

F:;E1 EROSION

—

coi

OPDOV

DL

SI

D MISSISSIPPIAN

—

URIAN

VON

TRUCTuPE

M

PRECAMBR

‘NINNIPEG RLD STONY PALAEOZOIC

INTERLAKE

ASHERN ELK D.WSON

;

SCURLS NISKU LYLETO

LODGEPOLE

MISSION

CHARLES

flgure

ClAN

SOZOIC IAN

RIVEP

POINT

SURFACE

MNTAIN

:—

RIVER

3

CANYON SAY

I

200

AN

EDGE C

I I

occurring ‘ith

longer

indicates

during

thickens

viously

T}’e

no

some

uppermost

gree increase

small

der. gradual lished

ure

stratigraphic

eration sippian

part

basin.

controlling nic

lesser

outcrop

section,

resents The rate

rate

right

The

The

The

appreciable

7)

framework;

isopac

The

outcrop

of

the

of

the

of

basal

area

angles

tectonic

area

undergoing

Stonewall isopach

extent

This

reflects

latest

described dolomitization. lithofacies

strata,

essentially

for

and

as

in or

change

to

result

Manitoba

a southward

within

Ordovician

of

might

significant

Silurian argillaceous oil

of

the

subcrop

marked

any

pattern belt

irregular

to

traps

for

thickening

Ordovician

of

gypsum

framework,

migration

break

a and

of

the

west

of

formation

it

of

continuation

the

other

the

all

Ordovician

be

a

differential

change

portion

a

outcrop

is

at

has the

thickness

post-Palaeozoic

thickening

strata

discordance

belts

Stony

expected

differs

Palaeozoic

dip

in

rather

outcrop

strata

also

thickening

the

change

shown

Red

exploration

content

been

the

near

and

section

occur

or

is

but Palaeozoic

a

of

as Mountain

belt,

(Figure

River

and

stratigraphic

highly

than

r-arkec 11 y

evident

strata

an

accumulation

earliest

of

and

the

belts

on

in well,

subsidence.

the

in

with

is

along

and

formations

so

the

between

may

Figures

rather

the

important

tectonic

to

Williston

formation

accompanied

to

Saskatchewan

also

that

although

shift

important

of

a

involving

a

8)

in

previously

the

periphery

formation

the

to

erosion

possibly

the

somewhat

decrease

Silurian

from

the

that

comprises

the

the

than

a

south,

in

outcrop

south.

isopach

8

framework

succession.

greater

Stonewall

in

and Basin

maximum

the maximum

and

factor

thus

the

the

there

surface.

a

include

Missis

similar

consid

in

by estab

and of

time,

strike

tecto

(Fig

more

9 This

is

unit

pre

bor

belt.

rep-

the

and

de

the

no

as

an

—4—

is

or

in in a

‘

features. tiation

gests

in

show

of

noted

The tion

resent, nation

tures,

to

will

pects

superficial less

and

have

pretation

sissippian

of

All

and the

nor number

em the

Devonian

north-trending

in

is

siderable tectonic

trolling

the

western

Silurian

a

jor

of

highly

relative

sequent

basin

work

lake

area.

truncation

post-Silurian

isopachs

tern.

erosion pach

eroded

all

Group

and belts

rassic)

and

The

The

The

offer

the

particular

the

completely

Deposition

subsequent

the

The

the

of

of

western

earlier

edge

controlling

be

structure of

it

within

Saskatchewan

new

that

no

been

boundary

topographic

also

the

Interlake

for

the the these

is

both There

was

complex

known

the

thus

Apparently,

isopachs

relative

most

across

overlying even

Elk

ia

(Figure dolomitized

evidence

Birdtail-Waskada from

(Figure ,

top

the of

element

framework

tectonic

pre-Middle

coincident

of Manitoba.

surface,

time,

extent

depositional

the

of

adjacent

and

and

origin

important

are

of

large oil

upper

strata

salt

Birdtail-Waskada

strata

maintained

Point

the during

local

the

of

reflects

more

factors

prominent

edge

best

the

of

is,

structure

marker-defined

importance,

southwestern

of

oil

contours different

the

accumulation

figures,

later

relatively

uplift

the

local

tectonic

Silurian

to

collapse

the

strata

map-area.

Prairie

zone zone

however, the

10)

of

by

part,

part

the 9)

of

of

during

origin

stability

accumulations

structure

along Group

lows

possibilities

strata

of

of and

important

the

Birdtail-Waskada

Interlake

border ,

Precambrian exact

“superficial” a

with

nature

these

the

Elk

any

Whereas

strata.

probably

of marks

Devonian

structures

next

basal

are

was

primarily

in

the

Manitoba,

approximately

of

of

relatively

is

occurrences

cycle

D

an

shows

this

on

in

the

and

on feature

this

element

Evaporite

controlling

Silurian features

the

apprecialfie

basal tectonic

evon

and

Point strata,

marks

Devonian

uniform

of

the

markedly

the Winnipegosis

may

structurea,

configuration

relatively

the

little

the

may

infiiljng

unit,

Devonian

as

the

of

(Figure

basin a

Axis,

It

axis

Manitoba.

and uncertain

isopach

Silurian

zone.

and

deposition

in

projected

in

extent

ian

major

the

are

eroded

an

Axis

Precambrian

the

marks

they

Manitoba

units

Devonian

for

uplift

Bnsin

top

be

account

the

evidence

located

the

determining of

and

during

the

the

i is stable

and isopach

irJier

or

salt

framework

the

almost

is

closely

In

Williston

throughout

which

salt

Interlake

merely the

the

future

time.

irregular of

the

of

or

beginning

of

anomalies

certainly uniform.

unconformity,

obscured

are 10)

topography

true

tectonic

of

this

Ashern Silurian

within strata

any deeper

20

whether

Silurian

the

and

collapse

Axis.

a

establishment

became

age

both

the

modifying

The

basin

locus

Churchill-Supe

Devonian

the

along

and

tectonic

shallower

is

Ordovician

these

fringing in

.

correct

miles of,

portion

uniform

of

However, dendritic

inter-related.

anomalies

case,

present

tectonic

Ashern As

suggests

comprises

erosion.

uncertain.

Ashern part,

oil

(possibly

Silurian

superficial

having

during

previously

the

the

progressive

This

Basin strata.

basement. ;

of

Devonian

the

differen

formation

the

and is

in

this

to

features. Tentative

they

it

features

surface.

explora

the

the

of

interlake

appears

evident

regard-

east

a

gypsum

for

marks

shown outcrop

frame-

a

inter-

south-

of

of

pros-

a

reef; large

maps

most Inter-

sug

east-

Mis-

rep-

f

fea

axis

and map-

con-

This

con-

are

are

with

was been

sub-

ma-

and

that

or-

pat-

the

the

iso-

the

the

in

of

Ju

of

a Ii’ ,: --.: :-

t•I III:: HU tt1:U4 W.t:[-Iflff 32mi-j. 4LIf .. . g i , ‘ “‘“ -. -- :_ - m-o wi—1iO;t3—;;

, ‘3

m

C)1

?

Hi-

(1 > rn -9 (nD 0> r: m IG) Co :oc” m < m :x H C0 >19 ‘1 •H0 ; 5 m 5z z

‘

above

where

Duck boundary, the

underlying but

was Birdtail-Waskada

!;::,.uc

some

Churchill-Superior the

the

preted

controlled

Winnipegosis

ening

Point

reef

relatively feet.

the features.

sis

nipegosis. reef

an

sin

as

preted

nipegosis

fined

sis _±

:::

0

In Neither

•

200

northward

was

infilling

general

Birdtail-Waskada and

.

west

formation

sufficient

or

complex

or

the

Mountain,

minor

This

of

unit,

the

Basin.

a

as

directly

to

overlying

not

bank

is

the

series

deeper

and

The

a

further

stable

reflects

in

feature.

300

Despite

inter-reef

Ashern.

tL:il-h

of

and

basin

probably

sufficient

facies

Prairie

and

large

tectonic

having

West

along

northwest,

the

thins

continuation unit

to

feet.

the

(Figure

from

of

Swan

part

shelf

overlapping

localize

framework,

Axis

next

Prairie

reef

the

part

thinning

this,

patch

boundary

tectonic

The of

,-I:

thickens

abruptly,

the

The local

Evaporite.

9

the

platform.

Axis

represents

movement

of the

to

topography

area

River

Devonian

during

development

a

the

trend

southeastern

11)

show

isopachs.

to lateral

Prairie

the

depositional

reefs

reef

Birdtail-Waskada

Evaporite,

is

framework

building

isopach

of a

,;

rather

rather

shows

zone

and

Elk

seen

of

coincident

maximum

and

of

Winnipegosis

on

growth

the

This

J

rise

equivalent

iL

The

the

—STRUCTURE-250’C.I.

units,

—ISOPACF-4O’

Evaporite

associated

f.REEF

the

the sedimentation

E

Dawson Point

.—.

it

of

The

occurred

to

Churchill-Superior

than

of

several

WINNIPEGOSIS uniformly

is

thinning

250

seems

Winnipegosis

up

a

be

structure

original reef

relief

edge

DEVON

OUTCROP

FORMATION

is

along

Figure

the

cannot

top

evident ID

the

reef

to

a of

with

discordant

Basin,

a

to

tectonically Bay I

edge

of

Winnipego of

JI

Winnipego

likely of

a

II

160

marker-de

of

::

represents

along

IAN

important

and

with

Axis,

300 time

the

the

fringing

the

is

be

a

the

as

extent

toward

in

areas,

of

to

along

thick-

inter-

along

C.

inter-

inter-

axis,

on

much

Win-

feet

Win-

that

and

—6—

the

the

the

the

Elk

the

180

I.

ba

to

a

Waskada

red

Bay

local

salt

represent,

this.

apparent

beds

of 15)

almost marine

Palaeozoic

from

the ture

least

is no

a ta. pensated

seen

sis

in Waskada

several

fracture-controlled

be

would

strata

and

tail-Waskada

circulating

salt.

reef

of ize

extensive ture

eastern

coupled

chewan) is

ure thinning

thinning

where

nipegosis

marker-defined

the

0):

+

to

deep edge porite

along

The

tance

represents but

of

The

solution

best

salt

Direct

A

.

evidence Figures

beds.

The due

more The

a

+

The

solution,

section,

features be

underlying

the

salt

Prairie

by

the

on

cross-cutting

Re-establishment

to which

200

or

number

thick

Also,

it

true

on

the

basal

Prairie

from

shown well

favour

certainly

much

Prairie

of

of

strata

to

the

the

northern

wells

the inasmuch

must

salt

be

bank

composite

area

isopach principal

solution

edge

Elk

the

with

Axis truncation

for

easily

.

to

Axis,

evidence

the

salt

is

in inter-reef the

pre-Mesozoic

salt

The

edge,

occurs

or

depositional

draped

underlying

minor

top

Birdtail-Waskada

control

15,

formation

Davson

is

due of

the

300

red

Evaporite

solution

a

more

by

underlying that

associated

Point

and

in have

deposits

along

part,

of

of

salt of

of Axis

field

Evaporite

collapse,

Prairie

the

down-warped

basinal

do

fringing

any solution

Evaporite

synclinal

of

17

where

seen

a

top

the

“reef

must

entirely

feet

shales factors

because

unit

the

salt

the

on

limit

(Figure

thickening are

the

in

as

structural

solution.

the

at

irregular

tectonic

feature

previously

extended

unit

and

over

for Basin

may

change

areas probably

solution

the

the

Swan

of

the

Bay

of

salt

if

Dawson

;

areas, the

has

fact

of

solution

the not

previously

that

Souris

have waters

facies.

consequently,

the

topography” Evaporite

of

the

section

and

of

(Figure

the 19

of has

data

salt

with consisting

southern

erosion

southern

Ashern

salt

probably

have Winnipegosis

insoluble

the framework,

is

flexure

to

basin.

is

Upper

the

outcrop

evident

occurred.

to

River

(Figure

present

is

show

total 12)

the

normal

Prairie

that

provided

shown

locally

in

movement

The

are

a

occurred

Prairie

than

one resulted

for

largely

channels.

to

the

solution

must Winnipegosis

lows

are

of

would

Prairie

a

overlain

River

Bay

which mentioned

thickening

caused

Axis, thiciess.

—

of

Dawsn

synclinal

the

is

certainly

certain

sharply

a

this section

area,

piece 13)

strongly

interval.

a

Palaeozoic

northeast

of

extended

indicated

maps.

part

mentioned

on

end

notably

porous

have

area very

in

thin.

residue

formation

the by

have

thickened

Evaporite,

21

of

marine

salt

formation

east.

It

the

coincident

show

Evaporite

the

have

an

during

(Figure

either

in

the

is

thinning

Evaporite

) along

fracturing

except

where

is

the

of

the

o

along

by shows

of

abrupt

reef.

considerable

tended

overlying are

on

an

aquifer

iop

Bay

It of

some edge,

isopach

defined,

been

A

the

This

noted

Mississippian

hinge

lack

suggestive

evidence

Winnipegosis

of

(This

suggests

the

cflssolved

the

the

Winnipegosis

the

will

Prairie

into

Winnipego

Dawson

very

approximate

is

on

from

reefs

the

of

believed

conditions

of

strata

the

the

the

Birdtail

probably

areas

the

Additional

for

a

Dawson

removed

Birdtail

uncertain,

solution 14)

and (Figure

this

of

the

draping

presence

and

salt

reflects

is to

the

normal

with

be

thinning

potash

or

present

number

for

Saskat

feature

in

is

reflects

struc

basal

abrupt

which

linear

post-

struc

Bird-

.

stra

with

corn-

local-

this

areas

seen

Win-

also

the

for

flex-

map.

that

Eva-

are

unit edge

the

this

At

of

the

the

Bay

dis

the

of to t

------

- - — - - - —— — —— - [ _: —

. -- -:—_ -

- .. - : Iu L ) j: T•1 i I ::

f• 1 3ir1 :L’g 0< -i-jo 1II!;i “ -tJ > ;u rT 0 > -tJ> ji1 >0 iz H;t3 —: i cn m I ii f\)Q o Z19 (I’ - 0_fl p..

[:. ;:Ui;i- Li, t:f3Eff; ‘1> 0 IIII:u fl-u -I : o< C :oI m []IJ (‘Jo 0 oz U, - z> [ o-fl fl—

,4

2

:

em

same

sharply

is

osis

ris

structures osis tributing

synclinal

kada-Axis

coincides

area. maximum

Elk 16) to

uniform

once

to

edge.

thickness

sin,

greater

axis,

salt

thickening

framework,

ratic

The

The

This

similar i

solution

River

or

part

shows

Point

reefs.

but

reef.

again

solution

area

where

This

general,

isopach

and

during

isopach

defined

subsidence thickening

more

thickening

with

of

strata

flexure

factor,

at

are

Basin,

subsidence

where a

to

it

Structure

probably

of

bear

indicate

to

relatively Dawson

the

as

their

is

Prairie

that

evident

of

Dawson

the

had

the

the

likely

of

might

local

possible

are

Birdtail-Waskada

little

the

a but

at

the

as

approximate

Dawson

erosional

northeast

of

in

occurred.

thinning

draped

could

represents

a

toward

the

Bay

Duperow

thick

it

the

to Evaporite

Souris

contours

in

in the

normal

synclinal

the

be

relation

Bay

may

the

the

that

the

salt

strata

area

expected

Manitoba

possibly

is

Souris

Bay

over

northern

limit.

time.

east

an

River represent

central

of

evident

of

edge,

tectonic

salt

In formation

.

of

the

edge

once

flexure

east-trending

salt to

attain

the isopachs

the

the

of

particular,

thick collapse

River.

Structure

formation

if

Axis. eastern

the

indicate

and

portion

buried

the

immediately

combined

part

of Birdtail-Waskada

again

along

area

pre-Dawson-Bay

framework

their

thickening

the

along

over-all

Birdtail-Was

complex

Souris

are

(Figure

This

of

However,

where

was

Winnipeg-

the

Winnipeg-

end

of

show

maximum

the

relatively

note

quite

contours

(Figure

the

zone

Winni

the

south-

is

a

of

River

basin

map- prior

local

Sou

with

con-

17)

the

salt

the

Ba-

due

the

—8—

the

er

of

a

possibilities

they part

tion, with

of

in

lapse

Two

tam

lack probability,

of

of appear fourteen 1arge.ypnnber

vicinity

or

the tive ing pattern

no

the

pattern

pegosis

tion,

in subcrop during

100

The

For

early

peai

well

surrounding

the

Figure

noticeable

end

the

reef-controlled

feet

are

of

of

directly

areas

closed

giving

stabilization features

,.

and

the

underlying

most

the

control

deep on

-

Duperow

is

of

are

salt

the

biostromal

structural

of

prominent

is

belt,

Prairie

the

seen

Nisku

14.

of

the

Birdtail-Waskada

the

structural

the

almost

these

for

rise

the

Birdtail

solution,

that well

prominent

earlier

; local

of

regional

the

however,

Mississippian

for

Devonian to

preceding

areas

Oil

result

synclinal

to

Evaporite

formation

control,

structures

time.

these

be

of

highs

thickening

Devonian

certainly

pre-Nisku

marked

local

nature

structural

structural

entrapment.

salt

Waskada

;

quite

would

the

highs

of

such

trends.

structures

In

this

feature

because

structural

collapse.

depositienal

differential

it

tectonic

maps

structiwes

of

irregular,

isopach

the

irregularities

appear

the

occur

(Figure

multiple-stage

are

is

apprs

strata,

oil

Axi

of

the

strata.

lo

highs

Axis

This

riot

northern

result

fields

the

because

also

of

of

It

unit,

along

and

represent

indicated

are

framwork

highs

later

possible

to

seems

this

Duperow

but

especially

noted

suggests

18)

highly

present

Because

possibly

occurring

truncation

cycle.

offer

of

where

are

evident.

but the

,

they

salt

of

map

part

salt

in

the

in

likely

coincident

previously

salt

there

probable.

to

excellent

southern

the

salt

the

salt

solution

in

at

collapse

by

isopach

reflect-

isopach

of

do

toward

a

is

in of

ascer

In

along

solu

most

least

area

that

rela

solu

lack

over

this

over

col

not

the

the

are

the all

4

!

. : ‘

I

-

tural

truncation

face

the

yon

the

fect trjHutjon kada

subsidence 20)

the

sic extensive

framework

Bakken-Lyleton

has Axis.

structural

this

number

21na_flt

liston major flects

ton

formable basal

a

The

Direct

The

The

composite

Williston

lower

erosion

Birdtail-Waskada

and indicate

occurred

of

formation,

axis,

(Figure21)

highs

Axis,

In

primarily

Basin

Mississippian

subcrcp

shift

Ba,kken-Lyl&ton

main

this

of

Lodgepole

addition,

interpretation

of erosion

Mississippian

tecLonic

probably

contact

than

highs,

of

synclinal

differential

in

inthe

underwent

formed

interval.

feature

the

that,

rather

unit

Basin,

in

the

Manitoba

map

but

adjacent

surrounding

piplie’al

time. the

of

shows

once

three

indicating

f

between

eiement

previously

strata

as

than

these it

Mississippian of

especially

of

by

eastward

lows

shales,

uppermost

However,

Axis.

a

interval

the

again,

the

Two

local

subsidence.

a

two

Lodgepole

early

of

result

the

is

parts

strata

along

along

slightly

map

Mississippian duriiiiippian

the

siale

the

uncertain

windows

isopach

of

These

and

Elk

areas.

the

that

along

mentioned

salt

truncation

of

(Figure

once

Mississippian

of

these

two.

during the

regional

the

Devonian

facies

Point

Manitoba

includes

salt

the

formation

greater

later

collapse.

are

the

thicks

Birdtail-Waskada

again

southern

The

of

basin.

areas

because

collapse

the

Basipwas

19)

shci\v

the

Birdtail-Was

Mission

salt

erosion

local

of

isopachs

is isopach

occur

the

pre-Juras shales

portion

degree

represenLs

result

In

the

the

are

The

(Figure tectonic

part

collapse

the

during

of

uncon

struc

addi

along

large

time

Can-

Lyle-

sur

now

dis

the

and

the

ef

re

of

of

of

of of

—9----

sidence

truncated

salt structure

Axis,

ed the

crop tion,

subcrop rise

crop

explanation

(Figure

ii

: :

-:

to

collapse,

to

Lodgepole

belts

a

belts

indicating

include

the

well-defined

along

belts

!.

22)

may

at

occurs

northwest,

is for

.

or

the

A

a

show

evident.

the

and

possibly

this

somewhat

8

pronounced

it

a

along

Mississippian

Churchill-Superior synclinal

may

a

change

earlier

can

rise

the

Whereas

parts

indicate

be

be

Mission to

•

larger

seen

due

up-dip in

strata

structure

the

of

orientation

erosion

to

the

0

the

further

if

southeast.

:SU8CRQP

portion

Canyon

flexure

the

show

post-Mississippian

Birdtail-Waskada

subcrop

which

boundary

map

surface.

tectonic

a

of

and

of

of

A

structural

is

the

has

the the

belts

possible

Charles

extend

basin

zone.

This been

sub-

sub-

sub- of

tectonic

the

paction

greater

superficial zones

associated centers

ity

on zoic to

the

uplift.

forces greater

trends

Palaeozoic thicker

exposed

for

during

strata, iderable

sin

degree

In

Although

a

sedimentation

between

two

Precambrian

the

underwent

time.

much

summary,

within

giving

and

this

and

of

and

of

are

magnitude,

response

deposition

structures

pronounced

at

portion

pre-Jurassic

with

In

continued

isopach

the

formations,

salt

the more

lesser

superimposed,

the

same

the

the

rise

addition

erosion

greater

solution.

these

subcrop

Churchill

then,

Manitoba

Superior

basinal

of

(Reprinted

basement,

area

at

to

degree

of

and

and

of

the

resñlting

discordance

certain

both

tectonic

features

the

Palaeozoic

has

to

Ordovician

uplift

surface.

structural

subsidence

Superior

superficial and

belts

Differentiating

facies

and

having

portion

block,

major

the

is

basin

been

from

especially

times,

may

of

and

previously

Superior

activity

from

east-trending.

have

of

critical

subjected

This

apparently

subsidence

tectonic

between

block

The

these

had

time,

features of

erosion,

be

and throughout

minor

structures,

differential

served

the

accounts

the

Canadian

the

a

during

provinces, to

strata

importance

most

Mississippian

between

Williston

direct

noted

elements

to

the

the

result

movements

discontinu

so

of

to

have

and

a

orogenic

Printed

that

tectonic

are

a

localize

Palaeo

isopach

greater notably

in

where

for

Mining

a

effect

much

basin

corn-

been

true

of

part

now

con-

and

Ba- the

—

in

all

of

a

10

in and

—

Wilson,

Porter, McCabe,

Canada

Davies, Bannatyne,

Andrichuk, Alberta

Baillie,

and

The

possibilities

strata evaluating

Royal

of jacent

laeozoic

The. No.

laeontology,

sources

Manitoba,” Branch

tion,

Publication

ton

tigraphy

Petroleum

gical

10,

Canada,”

This

Metallurgical

Natural

the

Honourable

pp.

1,

Tectonics

Basin

185

J.

of

H.

J. A.

History

paper

Society

Areas,”

pp.

Society

H.

Canadian

W.,

of

2333-2398.

Publication

Rocks

Manitoba.

F.,

pp. D.

.

D.

J.

B.

Amer.

the

and

R.,

Manitoba,”

124-189.

Geol.

Area,

Regions

.52-5,

and

Manitoba

for

M.

B.,

Industrial Resources,

et

B.

(1953)

was

of

Palaeozoic

of

Amer.

(1959)

Bulletin,

of

of

Selected

of

Sedimentation

al.

and

(1959)

Fuller,

(1966)

Publication,

Assoc.

the oil

Gurney

Acknowledgment

105

Petroleum

Shield

Manitoba,”

Canada

Western

presented

Northern

(1962)

:

66-1.

Brisbin,

Canadian

accumulation

of

Assoc.

:

pp.

“Devonian

Manitoba

Mines

:

Minerals

:

J. “Mississippian

Petrol.

July,

“O.rdovidan

Manitoba.

“Bibliography

Manitoba,”

in

References

tectonic

C.

:

Evans,

Special

“Geology

Petriil.

Cana1a,”

Geologists Northern

.

C.

W.

Williston

232

Branch

1967)

with

Maflitoba

--——STRUCTURE

Shield, :.:...:.:.:.:STRATA.

:::.:.:.::.::

in

Geel. M.

.,

Mines

and

C.

‘EROSIONAL

System

pp.

Minister

EROSION

Southern

lvi

SUBCROP

FRINCIPAL

framework

4ISSISSIPPLAN

(1959)

Publication

Geol.

the

(1962)

in

and ISSISSIPPIAN

Fuels

Bull.,

Fgure

Publication Manitoba

and

np.

Alberta

Branch

Manitoba,”

Stratigraphy

Basin

of

(1964) the

permission

Mines

of

Silurian

Bull.,

: 6045.

.

Geology,

Mineral

:

BELTS

in

Vol.

22

“Lower

SURFACE

RESERVOIR

the

“Tectonics -200’

Palaeozoic

EDGE

of

Manitoba,

the

and

:

Publica

Vol.

and

Soc.

Branch

43,

“Geolo

No.

Willis-

OF

Mines

Mines

CI.

Post-

OF

Stra

58-1.

The

Ad-

Pa-

Re-

Pa-

No.

43,

the

of

4,

of of