I/I? 1907/e6-43

REPOR1' ON LIMESTONE DEPOSI1'S I N THE VICINITY OF MELROSE & PALOONA

INTRODUCTION:

This report is based upon an examination made in January 1936 with the object of obtaining information on the physical and chemical characteristics of the limestone deposits and their extent in this area.

All outcrops were examined and sampled. The samples were channel samples or their equivalent taken across the strata at right angles to the strike. It is to be borne in mind that the analysis of a single sample from a deposit is merely indicative of the character of the depos it and much more detailed sampling and investigation is necessary to definitely prove the character of any deposit.

P2SVIOUS LITERATURE;

Cement Materials at Melrose and Paloona -A.M. Reid, 27/3/25

Cement Materials at Melrose - A.M. Reid, 3110/25

The Oil Shale Resources of Tasmania - Mineral Resources No . 8 part 1.

LOCATION AND ACCESS:

The Melrose-Paloona area is situated approximately five miles south-south-west of Devonport, the chief whipping centre of the north-west coast. It is well served with transport facilities by rai l and road; the old Don- Barrington tram passing through the centre of the district. The railway is in use only as far as the Melrose quarries , a distance of approximately 8t miles from Devonport, the rails having been removed from the Melrose- Barr ington section.

Several good motor roads give access to the area, the main ones being the Tarleton-Eugenana-Barrington and the Barr ington­Hamilton-on-Forth roads. The distances from Devonport would be appro%imately eight and ten miles respectively.

PHYSIOGRAPHY: The area under review presents marked variations in topographical relief due mainly to differential erosion. It is of relatively low relief and may be described generally as an area of fairly h igh hills and broad valleys . The present configuration of the land surface is largely due to stream corrosion.

The drainage of the area is effected by the Don River system; the greater portion of it being drained by the Me lrose Rivulet , a north flowing tributary of the Don.

No mountains occur within the immediate area although it is almost completely surrounded by relatively high country; Kelcie ' s Tier to the north risesm over 500 feet, while a little over two miles to the south-east the Brown Mountain attains a height of 1100 feet.

GEOLOGY: A number of rock-systems and formations of different periods, outcrop within the district. The oldest rocks are those of the Cambro-Ordovician system. Succeeding these , the oldest rocks in the district, are those of t he Silurian system. Succeeding all the above and overlying them, the Permo-Carbonif­erous system occurs. Pre-basaltic gravels etc . occur south of t he Broken Hill Proprietary Company ' s magazine . Tertiary basalt is represented by flow or flows north and south of Melrose .

As the actual convacts 'ere mas.ted in _learly a _l cases t. e tru", relations ips COU.l.u. not be dete"mi.neu.

A section, soutn from Tugrah to Paloona, suggests a conformable series of quartzites, sandstones ~nd slates, with a thic'c bed of limestone inteccalated.

I~ tne cutting on the Don-Lelrose daillVay about a ha.lf mile nonth of t.1e Lelrose station, sandstones and Q.uartz ­ites with a north 100 east strike and a hi_fi south-westerly dip are very ,ell exposed. These are follo led , a,parently conformably, by the lioestone beds. Only one small exposure vas observed south of tl.e lil,lestone and that was in a road cutting, ~n the .:elrose- Paloona road, just east of the old Paloona railway station; here a .;rit- .. ike sandstone appears to overly t.,o lLnestone . Further exposures to the south and east are concealed by basalt.

No accurate measurements of the extent of the limes tone vrere poss ible LJut the approximate ,{idth would be nearly three miles. The thickness proLJably exceeds 2000 feet.

With regard to the age of t,.is system, no very definite conclusion was reached . The slates a.d sandstones .lave been previously assi 'ned to Cambrian and the limestone to OrdoVician. As far as the field occurre.ce is discernible t"ere is no apparent reason to se."",rate tne r'ocks into t '0

systems, as tne sandstones, slates and limestones form one confor~able series. I n t e absence of definite st 'atigraphical and palse ontological evidence for the diVision of t,' is series into two systems, it is preferable for t' e present to refer tne series to the Cambro- Ordovician.

I.LU. IAN: Sandstones and qh~ rtzites belonging to this system unconfor~ably overlie and form t.,e I{estern limit of t:Je limestone. The strike is generally nor th- west , I'i th steep soutL-westerly dips.

Some fossi s Rynchonella (sp) were observed near Paloona .

~:e.!~~: .ocks of tnis age cover the extension of the lime­stone to t~e nort.-east ana east. They were formerLY more extensive but have now oeen largely removed by denudation.

The strata consists of sandstones, pebbly- ud~tones and mUdstones and are ei t"er horizontally bedded or dipp ing at small angles only.

Gravels, clays etc. belonging to this a6e occur on the ridge south of tne Broken Hill Propriet ,ry Co,npany ' s magazine south of the Don River and in the valley of the .. elrose Rivule t, near Paloona. They are classified as Lower Tertiary because tf.e basalt, which, in Tasr::ania is regarded as l: iocene, overlies ther.1.

LI:::E3TOEE:

The limestone [ener-ally , occupies the 10~llands and flanks the low hills . In the flat country, oet''1een the few isola ted outcrops, Ihich stand out prominently as rocky projec tions lith rounded contours, its presence is indiCa ted by a brick-red, clayey soil hardly distin~uishaLJle from that

derivea from the ~sa1t; tne present is extre.eLJ v r'ao1e least 25 feet in some )laces . country are usually devoid of

3r amount of clay overourden and reaches a deyth of at The eX..;Josures in t.1e nigher

cl ay .

The genera :::trE.e of the cleavage Ls _orth 100 -

200 eas t with a steep south-.vesterly dip; o':lin", to the upturned e ges percolating waters have easy access to cleavage planes and joint:.; and ores put dO'.'1n by the Broken Hill Pro rietary :Jo.npany have indicated tnt; ~res6nc. of clay oand::: ( 61 reI' ~ent insol uale) up to f~ve :eet t~ ick at depths of 100 feet .

The limestone wavy and even sc iatose. grey ; it :eathers alon~ I:!- te1'iaL.

varies in texture frc conpact to The dominant colour is a bluis:

cleavage planes to a liluG-coloured

Calcite, r eprecipitated from percol ting ~olJtions, has been deposited in cleavage planes, joints etc. and in places becomes fairly abundant .

No li,uestone deposit is entirely free from impur­ities, the most comnon of which are silica, alumina, iron compounds, organic matter and sulphur. Tge average compOSition of 14 samples taKen show that with prooably one exception , the Silica, none of the deleterious substances a1'e present L1 harmful amounts for most practical purposes .

Ca C03 89. 1 per cent varying fro:n 73 . 1 to 95 . 0 per (lm t

Acid Insoluble 6.<36 " " " " .3. 61~ " 20 . 6 " A1203 0. 40 " " " " 0 . 14 " 0.85 " ,\g 0 o. 76 " " " " 0 . 38 " 1 • 84 "

Fe203 0. 21 " " " " 0 . 34," 2.53 " ,nO 0 . 025 " " " " 0 . 01 " 0.09 "

Phosphorous 0 . 01 " " " " 0 . 01 " 0 . 04 "

Sulphur 0.10 " " " " 0 . 03 " 0.61 "

The a alysis of Nos . 1 and 11 suggest the presence of pyrite .

11 outcrops with sample sections 'efer'red to are located on the accompanying eeological mup . ~he heights sho.m were obtained by abney level readines in conjunction wi th the railway survey . The contours 8re re9.8 )ll9.oly accurate a t the indiv idual oJ+crops and, while those in tile vic ini ty of the Bro~,en HiLl Proprietary Company f s area were taken from one of the Company f s surveys, elsewhere, t ey are .. ,ore in the nature of for:n- lines anj are only very approxiwBte .

NO . 1 OUTCROP: This is S·tuated aoout six chains north of the Broken Hill Proprietary Co~pany f s office and is nearly 400 feet long and 100 ~eet wide; it rises to a height of about 30 feet above thf' ..,eneral level. The follo\'ling analYSis i!l.dicate tne qualit;y- of t •. e Ii !lestone: -

" "

" " "

" "

-- -------

Samule <- ee . No . 144) ITo .1 0 L-,e,:. Ko . 145.1

.. oi sture at 105°C 0 .1 0 0.1 0

Loss on ignition 39.72 39.84

Acid Insolu0le 8 . 00 7.36

CaO 50 . 2lj. 50.64

gO 0. 72 0 . 76

Al203 0 . 49 0 . 40

Fe203 0 .77 0 . 02

1 .. nO 0 . 01 0. 01

P205 0. 01 0 . 01

8 0. 06 0 . 04

Ca 003 90;~ 90 .1 5~

The most no_'t. erly outcrop (ro . 2) oc r.urs on A. Rundle ' s property approxime. ely six chains north of tL<:: !elrose railway station and extends t10rthFard , over a width of at least 400 feet for 15 chains. 'fhis outCl'OP ~ ises to over 120 feet a.oove river level and presents no f eatures strikingly different to the genera cr;aracter of tne lir .. esto!le .

A smaller outcrop occurs to t e east on '{al ter Lyne I S property bu.t this was not sampled .

The average quality of the stone is indicated by the fo l lowing analyse s :-

( 1 ) ( 2) (3) (4) (5) eg . l'ro .

136 .oi s:ture at 105°C 0 .1 2

Reg . Eo . rteg . l;o. Re:;.ro . _ eE · :·To . 137 138 1- 0 14.0 :J~ 0. 06 0. 06 0 . 06 0. 06

~oss on ignition 33 . 56 39.66 39.34 39. 60 -C' -4 :J, . J

Acid I nsoluole 20 . 60 8 . 84 10 . 80 8. 52 7. 88

GaO L 1 . 04 50.1 4 4 . 98 50. 24 5".7

i.:gO 0 . 38 0 . 59 0 . 49 0.62 0.49

A1203 0.53 0. 16 0.28 0. 17 0. 24

Fe203 2 .53 0.84 0.98 0 . 77 O.C'O

i nO 0. 09 0. 03 o. ~ 1 0 . 01 O. 01

P20 5 0. 04 0 . 01 0. 01 0. 01 0 . 01

8 0. 48' 0. 07 0. 06 0. 04 0. 05

803 0. 27

Ja C03 73 . 1 ~ 89. 75:0 87 . 5,~ 90.~

Due west of the Dl'o.cen Lll.L Pr'opl'ietary GJrr.p~ny I S

1:el1'ose <;,u_l'::,y, and ~u8t soutn of the Don _ iver, 1"0.3 oc:teru., ~ l_es t- B heibnt a ap'roximately 180 feet above se_ level, & .ct is, 60 feet auove tne ,;eneral ..;round level.fhe ._,ss 1ve uterop of l~_e.,tor_e extends over 450 feet 1'1 lengt n wi t .l a

.,.",ximum wi dt!l of at least 200 feet. A sl!ld .Ll Cluarry ',,'_ <> opened b;y 1.1eDSr& . vor·ne .Lius & Dally on tne soc-to. s i.e, mane' e~rs ago , ::0:£.1 tl1e pUllpose of out .. i.L'l':'nJ .Limestone :'Z'::r ol...rninu _

';'[,e stri:e 0: the cleavaJe north 150 eest ,i th "e al,,!oct vertical dip sho','!s no, rked deviation :'l'om t. e e er~l str:he and ~ip o~ the series .

:::.e average g,uality is i.1C.icated by the' following

Bo . 6 No . 7 Eo.8 Sample (Re,;; . 1::-0 .1 4 1 ) ( eg . lTo .1 42) (J.eg.!-0. 14 3 )

~.~oi::;tuJ..'le at 105 0,; 0 . 06 0 . 06 0.06

.l.J 08S on iunition 40 . 44 4 1. 50 41.76

ciG. I nsolub.le 6 . 56 3 . 64 5. 2:::

Sa 0 5 1. 34 53 . 22 -0.50

!._gO 0 . 7a 1.00 1 • tl!~

_1 203 0 .17 0 .1 4 0.34

Fe203 0 . 49 0 . 34 0 .70

MnO 0 . 01 0 . 03 '") ,,-• :J

P20 5 0 . 03 a . 06 0.06

S (laCO] 91 .75% ~j . 0;6 90 . O,~

_..-roJCimf tely one naIf ,L.e west - soutll- /est of t_.e Bro_re:1 SiL Pl'opri tary Co ,parv I s quarr, a s,,!all o\. ucrop :- 0 . 4 oocurs nee,r the westel'n bound:::ry of G. E. C:ooper I s 139 acres S.S. property. It in over 300 feet in lengtn ~ith a uaximwn ,idt:l of at .least 150 feet anj r·ises nearl y 50 fee t above the "enera ... !leve l. a?proximately 170 feet above sea level. ground

The cnarac~er of tnis deposit differ s in no ~y from t' e other outcrops described . fell small, :;'solated outcrops &_'e ex)osed in the ",elrose • i vul",+; for '" fc.rtner distance of four c!,ains tD tne .'est . No oU'~Grops occur .'est of t:;is exposure .

T: e :'ol.lowinv a:1alysis is indic&tive of t .. e average quality .

Sam.)le , 1(0 .13 (Reg . No . 1 1~8 )

I:oisture at 1050 0. 10 per cent

Loss on ii;nition '.a . 80 " 11

cid Insolub ... e 5 . 68 " 11

Sa!! 11e ITD.13 (e, . 1'0.14 ) ,

CaO 51 10 per cent

.gO 0 . 72 " " A1203 0 . 68 " 11

Fe203 0 . 92 " " LnO 0 . ')3 " " P 205 J.01 " tI

3 0 . 03 " " CaG03 91. 2 per cent

l.r. tl.e old reserved rOB-d about a half a mile soutn of t'.e ea Hill Proprietary Company I " <;;.uarry a small outcro. ~To. 5

~ ns soutil of the area proved by t:. t Co.npany oy means of e8. Further sout!., Tertiary ..;rave_s and 'oasalt IT'.as;c any

sion of the Ii .estone .

e aane average quality is ,aintained as t. e follov'i:lo

£: -

SamJ_e

I,ioisture at 1050C 0 . 08 per cent

Loss on ignition 40 . 22 " " Acid Insoluble 7.28 " CaO 50.50 " " MgO 0 . 44 "

A1203 0 . 85 " " Fe203 O. 70 " tI

l:nO 0 . 04 II II

P20 5 0. 01 I I II

S 0 . 03 " " CaC03 90 .1 per cent .

oout 12 chains east of the Don River brid~e on the Eugenana­_'cse road, A . • • • undle has opened a quarry in the most

teo ly of the prominent outcrops (I-To. 6; for the :;Jurpose of aining lLLebtone for burning. The oVo:l r burden reaches a de th

_ at _east ten feet . The limestone .las almo:::;t a une:ssic cture with eyes of calcite well deve loped . The strike is

rt .. 100 east and t,.e d i p ~ .imos t vertical. This ex:?osure is v re south of the Don River by o~salt .

':'. e average quality is 1. dicated by t e follo'.vin", ena ysis : -

Moisture at 105°C

Loss on ignition

cid Insoluble

CaO

190

CaC03

Ho . 11 c- eg . Ho.146)

0 . 08 per cent

38.44

9 . 64

4S . 48

0 . 72

0 .40

0 . 92

0 . 03

0 . 01

0 .1 9

0 .1 0

88 . 5 per cent.

"

"

" " "

" " " " "

The only other exposure worthroti"lg is the outcrop :~o . 7 occurring on J. Jefferies ' property about eight chains sout -east of where the overhead railw,,_y bridge crosses the l.elrose- Paloona road. Here the limestone is exposed over a

idtn of at least 15 cnains to a height of 240 feet on t .. e side of a hil.L ris ing, on a grade of about 1 in 3, -.I11e1'e it is overlain wi th basalt, at approxima t e l y 460 feet above sea leue .L .

The li ,.cstone appears to be more massive in this xposure than those f urther north, although there is little

variation from the general composition as t; e follo-"ing indicates:-

Sample No .1 2 (Reg . ~-0 .1 47)

Mois ture at 1050C 0 . 08 per cent

Loss on ignition 40 . 90 " cil Inso.l.uble 6 . 00 "

CaO 50 .70 " gO 1 • 12 "

1203

o. 70 "

Fe203 0 . 56 " . nO 0 . 01 "

P205 0 . 01 " S 0 . 03 "

Ca C03 90 . 25 per cent.

CONCLUSIONS:

From this brief examinat ion, "'hieh i'1cluded only those outcrops out side the Broken Hil l Proprietary Company ' s ma i n quarry at l.;e lrose and the area bored south of the Don River, it was readily e.pparent that almost unli.,ited Quant ­ities of good average grade limestone are available; that t e limestone cont i nues to a depth far below the reach of mining operatilons, is 'vi thout doubt .

Situated on co~pletely cleared agricultural lands, within eight or nine miles by rail and road from Devonpor t an important shipping centre, and re<;.uiring, to corr~'!1a!ld tne most dis t ant outcrop, only the relaying of rails on the existing formation, for a distance of less t_1an three .niles, the conditions for economical operation '~ith excellent trans ­port facilities are extreme l y favourable.

Mines De artment , HOBART .

17th June, 1937 .

,

Q.J. HENDERSON, ACTING FIELD GEOLOGIST