Morphology and genesis of calcrete in South Australia with special reference to the southern Murray Basin and Yorke Peninsula

MORPITOLOGY A}ID GENESIS OF CALCREÎE

IN

SOUIU AUSTRALIA ITITH SPECIAT REFERENCE 1O

TITE SOUTIIERN MURRAY BASIN AND YORKE PENINSTÍLA

John Charles

Dfxon, B.A.I{ons.

^(N.S.!ü.)

Sub¡nLtted

in fulfllnent of the

requlrements

for the

degree

of

Ma*ster

of Arts The Uníveîsity of Adel-aide

L978

,''1.,r,,,,1., t.",'!' I

STATEMENT OF ORIGINALITY

Thfs thesis

Ls based on

origínal

^reseatch

carried out in the

Department

of

^Geography,

Unl.versity of Adelal-de. It contains

no

maËerial

prevlously

publfshed

or wrLtten by another authorr excePt where due reference

ls

^made

fn the text of the thesis.

John

C.

Dixon

ACIC{O!üLEDGEMENTS

The compleËion

of this thesis

^woul-d noÈ have been possible

wíthout the

assisËance

of a

number

of

^people

to

whom

I

am most

grateful.

In partieular I

would

1lke to

^Èhank:

Dr. C. R.

T\¡1dale, my

supervisor, for hÍs interest,

^{advÍce and}

lnvaluable críticism.

Mr. J. Hutton from C.S.I.R.0. Dívisíon of Soils for hfs assístance and advíce with X-ray fluorescence analyses.

Mr. J. Píckeríng fron C.S.I.R.O. DlvisÍon of

Soil-s

for his assistance and advice on the preparatÍon of

samples

for X-ray diffraction

^and

for interpreting X-ray powder photographs.

Miss

C.

BarringËon,

cartographic assiátant in the Department

of

Geography,

for printlng

photographs so

speedily

and

effíciently.

Mr. F. H1lton,

eduqation secÈ1on, South

Australian

Museum,

for

ldentÍfying the molluscs.

CONIENTS

STATEMENT OF ORIGINAIITY

ACKNO!üLEDGEMENTS

TABLE OF CONTEI.ITS

LIST OF ^TABLES

LIST OT'FIGURES

ST]MMARY

C1IAPTER

I

IMRODUCTION

Ain of

Thesis

Deflnition of

Calcrete

CHAPTER

II

GEOLOGICAL SETTING

The Murray Basín Yorke Peninsula

CHAPTER

III

MORPHOLOGY OT CAICRETE

IN

THE ^MI]RRAY BASIN AI{D ON YORKE PENINST]LA

leminology of

Cal-crete VaríeËies

CalcreÊe

Varieties in the Murray Basin and

on Yorke Peninsula

Murray Basin and Yorke Peninsula Calcrete

Proffles

CHAPTER IV THE CIIEMISTRY AI.ID MINERALOGY OF CAICRETE

IN

TIIE MURRAY BASIN A}TD ON YORKE PENINSUÏ,A

Calcrete

ChemÍstry

-

IntroducËion Gross Chenlstry

Discussion

Chemistry

of PrincÍpal Calcrete Types

Spatlal Variation of

CalcreÈe Chemistry l"flneralogy

of

Calcretes

Clay Mineralogy

1 1 4 PAGE

i

l-l- l-Ll-

v

ví

vl-l-l-

13

20

20 22

29

46

7 7

46 46 52 54 57 60 65

CHAPTER V GENESIS OF CAI.CR.ETE

Prevl-ous

Investlgatlons

Origin of the

Murray Basin Calcretes

Source

of

Calcir¡m and ^Magnesium

lons in

the Murray Basin

Genetic

Inplications of Calcrete Morphology fn the Murray Basin

Orfgin of

^{Yorke Peninsula Calcretes}

Source

of

Calcium and Magnesium

lons

on Yorke Peninsula

Genetic

Implications of

CalcreËe Morphology on Yorke Peninsula

CHAPTER

VI

SUMMARY AÀTD CONCLUSIONS REFERENCES CITED

68 68 69 77

79

81 83

84

89

92

2.L

tt

4.L 4.2 4.3 4.4 4.5 4.6 4.7 4.8

LIST OF TABLES

PAGE

Stratigraphy of the

MurraY

Basfn I

Stratlgraphy of Yorke Peninsula 15

Chemícal analyses

of calcrete

samPles

from the

^Murray

Basin

47

Cheñ1cal analyses

of'calcrete

^{samples from Yorke}

Penlnsula

49 Mean

oxlde

percentages

for calcrete

tyPes

ín the

Murray

Basín

55 Mean

oxide

percentages

for calcrete types on Yorke Peninsula 56

Elemental

raÈios in different rock envíronments 58 RatÍos of major elemenËs in Yorke Peninsula calcretes 6L

Calcite

and dolomlte percen¡ages 1n

calcretes of the

^Murray

Basln

63

CalcLËe and

dolomite

percentages l-n Yorke Peninsula

caLcretes

64

1.1-

r.2

3.1 3.2 3.3

3.4 3.5

3.6 3.7 3.8 3.9

3.L0 3.11 3.L2 3.13 3.L4

3.15

LIST OF FIGURES

LocaËion ^map

of

torrns and sanple

sites Ín the

Murray Basin LocaÈÍon map

of

torüns and sample

sites

on Yorke PenÍnsula NeÈterbergs stages

of calcrete

developmenË

Massive hardpan

calcrete with lamínar surface

Strongly indurated

^hardpan

calcrete with

nodules

floatíng in the matrix

Continuous hardpan calcreÈe

horizon, Vírgínia, Adelaid Plains strongly induraEed hardpan calcrete showing stromatolítÍc

appearance

of

^{larnínar calcreÈe}

Calcrete profil-e Monteith

_Quarry

I,

Murray Brldge CalcreÈe

profile, Monteith Quarry II, Murray Brfdge Calcrete profile,

Dukes llÍghway, Tail-em Bend

Calcrete horÍzon

^developed on limestone

of the

^Mannum Formation, Murray Brídge

Calcrete horizons, OLd Martlns Quarry, Black H111 Lamínar calcrete lenses, Martins Quarry,

Black

IIi1l Calcrete horizon,

Councíl

Quarry,

^{Black HíL1}

Calcrete horizon

on

granite

weathering

profile,

Long Ridge

Ilorízon of calcrete nodules and cobbles, Ardrossan, Yorke Peninsula

CalcreËe

profile in coastal cliffs, Port Julia

3

2L 25 26

27 28

30 31 32 33 PAGE

2

34 35 36 37 38

39

PAGE

3.16 3.L7 3.18

3 .19 3.20

Calcrete profile at !üoo1 BaY Calcrete Proflle, Port Vincent Galcrete proflle west of Yorketown

Calcreted

Plelstocene shell bed, south west of Warooka Calcrete proflle' Moonta BaY

40

4I

43 44 45

SI]MMARY

The aím

of thís thesÍs is to

descrÍbe and account

for

the

calcrete

which occurs

extensively

throughout

the

Murray Basin and

Yorke Peninsula

in

southern South

Australla

and

to

see what

líght, if any, their Ínvestígatíon

thro!ìrs

on simí1ar features developed

elsewhere.

Cal-crete

fs widely dfstríbuËed Ín

South

AusÈralia. It is of

considerable geourorphological

sÍgnificance

and

fs ín

^some

quarÈers used as

a stratigraphic marker. Yet there

has been

litt1e

work done on

the

morphology and genesis

of

these

deposits.

^Unless

we understand Èhe ways

in

which

calcrete

forms

it is

obvÍously

fruitless

^{Èo draw} conclusions from

íË

about

the

age

of the land- surfaces on whlch 1L is developed.

In order to

^come

to

^some undersËanding

of the

processes

responsible for the formation of calcrete the chemisËry and

mineralogy

of calcrete

from

various sftes in the

two

selected

study areas úrere examined

using X-ray fluorescence spectrometry and X-ray

diffraction techníques.

The gross morphology and geomorphological setÈlng

of the calcretes also

provided

information

on

the

processes

of

formatlon.

FÍeld

observatíons and

laboratory

analyses show

that

^the

calcreÈes

of the Murray Basin and Yorke Peninsula form in various

rüays. In the Murray Basin the occurrence of consíderable quantities of palygorskiÈe, sepíolite and dolouiÈe strongly suggest ËhaË nany of the calcretes developed there are of lacustrine origin. The dominanÈ

elay mlnerals in the calcrete from the wesËern nargin of the Murray Basin are Íl-lite and kaoliníte which suggests Èhat Èhe carbonates

are of a

pedogenic

origin.

^{0n Yorke} Peninsula a1so, where the domÍnant

clay minerals ln the calcrete are illÍte

and

kaolfnfte

^and

where dolomÍte

coritents are very 1ow, pedogeníc processes are responsible for the formatfon of Ëhe exte-nsive calcrete hardpans.

Cal-cretês

of the

southern Murray Basin appear

to

have been

fonred

1n

shallow saltwater lakes related to Pleistocene

^marÍne

regressions.

The

calcretes of

Yorke PeninsuLa have been deríved from

the

soluËion and subsequent

redeposition of carbonates in the Pleistocene aeolian dunes and sand sheets whích cover large areas

of the

landscape and

from the TerÈiary

and Cambrian limestones on

whlch

the

younger sediments

are

developed