AUSTRALIAN MUSEUM SCIENTIFIC PUBLICATIONS

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1 AUSTRALIAN MUSEUM SCIENTIFIC PUBLICATIONS Hdge-Smith, T., Mineralgical ntes. N. III. Recrds f the Australian Museum 15(5): , plates xxvii xxx. [6 April 1927]. di: /j ISSN Published by the Australian Museum, Sydney nature culture discver Australian Museum science is freely accessible nline at 6 Cllege Street, Sydney NSW 2010, Australia

2 MINERALOGICAL NOTES N. 3.* By T. RODOE SMITH, Mineralgist and Petrlgist, the Australian Museum. (Plates xxvii-xxx.) CALCITE. GARIBALDI MINE, LIONSVILLE, NEW SOUTH WALES. (Plates xxvii, figs. 1-4, xxviii, xxix, fig. 1 and xxx.) Sme frty specimens f well crystallised calcite were cllected by Mr. D. A. Prter in July, 1916, frm the Garibaldi (Gld) Mine near I,insville, abut five miles west f the Upper Clarence River, Parish f Churchill, Cunty f Drake, New Suth Wales. The mine is situated in very rugged cuntry n the side f a spur abut 7 feet abve the Linsville pst ffice and abut a quarter mile t the west. Accrding t Mr. Prter, the men were driving a tunnel and had driven abut 150 t 2 feet when they nticed that ne f the walls sunded quite hllw. They put in a charge f explsive and expsed a cavern with a cubic cntent f abut 12 cubic feet, but cntaining n calcite crystals f any nte. The flr f the cavern was level with the flr f the tunnel and n the far side was a deep natural well abut six feet in diameter, filled with clear water, the walls prbably cvered with calcite crystals. Beynd the well is a bar f rck rising up diagnally, and abut tw feet abve the flr is a "mall pening leading int anther chamber slightly larger than the first and cmpletely lined with calcite crystals. The largest single crystal cllected by Mr. Prter measures apprximately 33 cm. X cm. X 28 cm., althugh very much larger crystals d ccur, as I have seen ne weighing several hundredweight. Sme f the smaller crystals are quite transparent, but the majrity becme mre r less cludy tward the centre. ' There appears t be n reference t the gelgy f the mine that will help t thrw any light n the rigin f the cave r the calcite. Mr. Prter reprted that he was unable t find any limestne in r arund the mine. Only tw specimens in the cllectin cntained matrix, In ne the calcite is depsited n quartz cntaining minute ddecahedral and cubic crystals *]'r N. 2, see" Recrds f the Australian Museum," vl. xv, n. 1, 1926, p. 69.

3 314 RECORDS OF THE AUSTRALIAN MUSEUM. f pyrite disseminated fairly abundantly thrughut. The matrix f the ther specimen cnsists f a sft clayey material varying in clur frm greenish-grey t almst black. In view f the lack f any definite infrmatin n these pints, I visited the mine in December, 1925, accmpanied by my clleague Mr. C. M. G. Friend. Unfrtunately mst f the calcite crystals had been remved and many fine crystals brken up in the search fr Iceland spar suitable fr ptical purpses. Hwever these mining peratins greatly facilitated the study f the structure f the cave. It was at nce bvius that the cave had frmed alng an almst vertical fault plane cutting acrss the Garibaldi lde. The fault plane is indicated by a narrw fault breccia and the presence f much slickensiding. In the cave the rck n bth sides f the fault plane appears t be identical. It is a very much altered felspar prphyry. Under the mierscpe the phencrysts f felspar are seen t have been cmpletely altered in many cases t saussurite and the grund mass cnsists f a fine grained cmplex f chlrite, calcite, and cmpletely altered minute felspar laths. An examinatin f the re channel material f the Garibaldi Mine reveals the fact that it cnsists mainly f much decmpsed cuntry rck with quartz, calcite, and a little pyrite. The gld is nt evenly distributed but is fund in patches. The assciatin f quartz and calcite is perhaps the mst cmmn t be fund in veinstnes, and in the numerus veins that ccur in the district it is quite characteristic. A careful search was made fr the presence f limestne in the vicinity f the cave, and fr a radius f three-quarter mile at least, nthing but igneus rcks was fund. The cuntry is extremely rugged and cvered with a semi-trpical vegetatin rendering an examinatin smewhat difficult. The evidence f the bulders and pebbles fund in the creeks draining the area failed t reveal the presence f limestne. In a private cmmunicatin frm Dr. W. F. Straubel, manager f this mine, received since my return, he in. frms me that marble has been reprted abut eight miles nrth east f Linsville. It is extremely dubtful whether this marble bears any relatin t the calcite under review. The Garibaldi lde has nt been displaced by the fault plane alng which the cave has frmed, s that it is evident that the fault plane is the lder. It is very prbable that the riginal cave was frmed by a buckling f the rck alng the fault plane at the time f its frmatin, and is therefre lder than the lde. Althugh the cave is separated frm the lde by cuntry rck, the gld-bearing slutins must have penetrated the cave and there depsited bth quartz and calcite. The fact that the cuntry rck has been affected by these slutins fr a cnsiderable distance frm the re channel, and that a specimen f calcite with quartz and pyrite has been fund in the cave, lends supprt t this view. The rf f the cave has fallen and the riginal flr f the cave may be many feet belw the present flr. It is certainly at least ten feet

4 MINERALOGICAL NOTES~SMITH. 315 belw. The falling in ftherf appears thave been subsequenttthefrmatin f the lde, as Iwas unabletdetect the presence f anyquartz r silica in any frm n the walls and rf f the cave. It wuld appear then that the crystals f calcite at present lining the cave have nt been depsited frm the gld-bearing slutins respnsible fr the frmatin f the Garibaldi lde. In the absence f any limestne in the vicinity, the surce f supply f calcium carbnate necessary fr the frmatin f these huge crystals f calcite must be sught in the lde material and the impregnated cuntry rck. Calcium carbnate is being depsited n the walls f the different levels f the Garibaldi Mine at the present time at a fairly rapid rate. It is bvius that these waters wuld be capable f depsiting the calcite in the cave, prvided that the inlet was greater than the utlet. In this cnnectin it is significant that the cave was full r nearly full f water at the time when it was pened up by the miners. Under these cnditins the circulatin f the lime-bearing waters within the cave wuld be very slight and with a cnstant supply f calcium carbnate the cnditins fr crystal grwth wuld be ideal. The crystals ccurring in the cave are divisible int tw grups: (a) the Rhmbhedral-scalenhedral Grup and (b) the Prismatic Grup. The frmer grup includes all the large crystals and a fair number f the smaller nes, while the latter are invariably small. In general the prismatic crystals are f a later generatin than the thers; thugh cccasinallythey d belng t the same generatin (Plate xxviii). Very ften they are depsited n the larger crystals and separated frm them by a thin layer f calcareus mud. In sme specimens, after being kept in a dry place in the Museum fr sme time, the layer f mud dried and cracked, lifting the small prismatic crystals frm ff the larger nes. The evidence f the mud indicates that there must have been a break in the ideal cnditins under which the large crystals develped. This break must have been f relatively shrt duratin during which much fine mud was brught int the cave water and depsited alng with the calcium carbnate. Eleven crystals were selected fr measurement; nine f these were measured n a tw-circle gnimeter and the thers n accunt f their size with an rdinary cntact gnimeter. It will be seen frm Table I that seventeen frms have been recgnised. The lettering in this table is accrding t Gldschmidt and the indices crrespnd t his G. psitin. Tw dubtful frms nt shwn in the table als ccur; ne, c: (i I 5 2), is represented by tw small faces in crystal ii, ne giving an excellent signal and the ther nly a fair. The measured cp and p angles are 10 10' and 51 52', and the calculated angles are 10 53' and 52 32'. The ther frm is represented by three narrw faces giving nly fair signals and measurements f 2 17' and 76 34' fr the cp and p angles. This des nt crrespnd t any knwn frm, the indices being ( ), and the calculated cp and p angles 2 22' and 76 '.

5 316 RECORDS OF THE AUSTRALIAN MUSEUM. Table I: Distributin f frms. Frms i ii iii iv I v I vi vii I viii ix x xi ,-- 0(01) X X X X X b(l 1 2 0) X X y(808j) X X X f'(i 1 2" 2) 15'(11'22) 1]' ~ 4 85) X X X p' (1 1 21) X X X X X X X X X X \H4483) X X rp' (2'2 4 1) X X X X X X X X m'(44 'ill) X X X X X X X II'(8~161) X X e:(2132) X X X 0:( ) X K:( ) X X X X X, I 0:(6 1 71) X X X X X I f ;(8'4121) U(6 2'8 1) X The crystals measured frm fur distinct types. Type 1. (Plate xxvii, fig. 1.) Crystals i-iii are f this type and they are all cmparatively small. The characteristic frms are the psitive rhmbhedrns p'(1l21) and m'(4481), the negative rhmbhedrns 1]'(4485) and rp'(2241), and the scalenhedrns e:(2132) and K:(4151). In every case the last named frm is represented by a full cmplement f fairly large faces giving excellent signals, and it was by this frm that the crystals were centred. The J aces f the frms 1]. (4485) and e:(2132) were dull and smetimes irregularly pitted, in every case giving pr signals. All crystals f this type have a plane f attachment apprximately parallel t a plane passing thrugh the vertical axis and ne f the hrizntal axes, Crystal i :-This crystal measures apprximately 6 mm. X 4 mm. alng the vertical and hrizntal axes respectively. In additin t the characteristic frms f the type, the secnd rder pyramid y' (8081), the negative rhmbhedrn ~'(4483), and the psitive scalenhedrn U(6281) are present. These are all represented by relatively small faces, and in general give nly fair signals. The last frm is interesting in that it is a cmparatively rare frm and is represented by its full cmplement f faces. Crystal ii :~This crystal measures apprximately 5 mm. X 4 mm. alng the vertical and hrizntal axes respectively. The basal pinacid is very small and slightly pitted but gives a gd signal. The dubtful frm l': (-4:'[52) as described is abve als present. With these additinal frms and the absence f y'(8081) and U(6281) the crystal is similar t crystal i. X X X,

6 MINERALOGICAl. KOTES-SMlTH. 317 Crystal iii :-This crystal measures apprximately 10 mm. X 8 mm., and has nly ne frm, the psitive scalenhedrn 0:(6171), in additin t the type frms. It is represented by tw very narrw faces giving rather pr signals. Type 2. (Plate xxvii, fig. 2,) This type is represented by crystals iv-viii, and includes all the larger crystals as well as sme f the smaller nes. The plane f attachment is rughly parallel t the plane f the hrizntal axes. The psitive rhmbhedrns p'(1l21) and?n'(msi), the negative rhmbhedrn gl" (2241), and the psitive scalenhedrn K:(4151) are the frms characteristic f this type, thugh the last frm is always present as a relatively small face. The frm p'(1121) is generally striated parallel t the edges P' / m' and P' / K:. In the larger crystals m'(4481) and K:(41'51) as narrw faces actually alternate with p'(1121) fr sme distance tward the apex f the crystal. Crystal iv :-This crystal measures apprximately 20 mm. X 16 mm. and in additin t the type frms, 1l'(S8161) and y(80s1) are als present. Bth the frms are represented by small, nt very bright faces, giving nly fair signals. Crystal v :--This crystal measures apprximately 18 mm. X 20 mm., and is similar t crystal iv except fr the additinal frm G:(ll 5 165) which is represented by its full cmplement f faces which are generally dull. The striatins n p'(1121) are parallel t the edges p,/rn' and p /G:. Crystal vi :-This crystal measures 18 mm. X 20 mm. The basal pinacid, which is the nly additin t the type frms, is present as a small narrw face giving a very gd signal. Crystal vii :-This crystal measures 22 cm. X 11 cm. and the interfacial angles measured with a cntact gnimeter are given in table Ill. The basal pinacid is a relatively small triangular face. One f the type frms, m' (4481) is nt represented) but in additin t the ther type frms the psitive and negative rhmbhedrns f' (1122) and b' rn22) are present, the frmer being represented by its full cmplement f faces, the latter by ne face nly. Crystal viii :-This is nly prtin f a crystal having five cleavage faces present and measuring alng the edges f the rhmb 23 cm. X 15cm. X 5'4 cm. Only the type frms are present n this prtin f the crystal. The measurements were taken with a cntact gnimeter. Type 3. (Plate xxvii, fig. 3.) In crystals f this type the basal plane mayr may nt be present. The nly ther frms present are the psitive rhmbhedrns p'(1l21) and the psitive scalenhedrn K:(4151). This type f crystal appears t be smewhat rare in the cave, as nly three specimens cntaining clusters f crystals f this type were fund. The crystals in every case were relatively small. Crystal ix :-This crystal measures 10 mm. X 10 mm. alng the vertical and hrizntal axes respectively and was the nly crystal f this type measured. Only type frms are present.

7 318 RECORDS OF THE AUSTRALIAN MUSETJM. Table Il. The measured and calculated cp and p angles. Frm Measured p Calulated p Errr <P I-p 0(0 1) b(1 1 20) Y(8081) 1] '(4 4 ~ 5) p' ( ) ~'( ) <P'(2241) m'(4481) II'(8816 1) e:(2 1 32) G:(l ) K:(4151) 0:(61'71) J: (84121) U(6281) / Table Ill. The measured and calculated interfacial angles fr calcite, Linsville. The measurements were taken with a cntact gnimeter. Letter Angle Measured Calculated -,,, 0 " i 1122 /\ , i j' { 1122 /\ P' llil /\ m' 4481/\ ' <P K: f ii22/\il l 1122/\ f 2241/\ l 2241 /\ { 4151/\ /\ I

8 liuneralogical NOTES-SMITH. 319 Type 4. Crystals f this type pssess nly the basal pinacid and the first rder hexagnal prism b(1l2t1). In rder t determine which prism was present crystal x was cleaved. Crystal xi (PI. xxvii, fig. 4) is really a cmpsite crystal and des nt belng t any f the types s far described, and s far as the depsit is cncerned is quite abnrmal. It measures 4 mm. by 2 mm. alng the vertical axis and its greatest width respectively. The frm p'(1121) is represented by its full cmplement f faces and the negative scalenhedrn t;: ( ) by nly half its full cmplement. The basal pinacid is striated parallel t the edge 0/ p. and in places its psitin is ccupied by numerus small rhmbhedral terminatins. The cl axis f the tw parts f the cmpsite crystal exactly cincide and the hrizntal axes are parallel. The first rder hexagnal prism b(1120) is present in bth parts. CALCITE. HANGING ROCK, NUNDLE, NEW SOUTH WALES. (PI. xxvii, fig. 5 and PI. xxix, fig. 2.) Five specimens f crystallised calcite frm Hanging Rck, near Nundle, in the Parish f Nundle, Cunty f Parry, New Suth Wales, are cntained in the Museum cllectin. Only tw frms have been recgnised; the psitive rhmbhedrnf' (1122) ccurring as large faces giving gd signals and the first rder hexagnal prism b(1120) as smaller faces generally much crrded and invariably giving bad signals. In sme f the smaller crystals the prism faces are entirely absent. The largest crystal measures 3 cm. X 6 cm. alng the vertical axis and the hrizntal axes respectively. They are assciated with crystallised quartz. On sme f the crystals minute crystals f pyrite are depsited. They are s small that their frm cannt be distinguished under the pcket lens but under the micrscpe they are seen t be perfectly frmed ctahedra! crystals. It is interesting t nte tha,t they appear t be very much mre numerus n and abut the prism faces. Table V. The average measured and calculated cp and p angles fr calcite, Hanging Rck, Nundle. Measured Calculated I=p-= Errr Frm --- cp cp p cp p,, ---,, I, " " " " b(l 1 "20) f'{1122)

9 320 RECORDS OF THE AUSTRAI,IAN l\iuseum. ACKNOWLEDGMENTS. T Mr. Anthny Hrdern, wh generusly defrayed expenses in cnnectin with the field wrk, Dr. W. F. Straubel, Manager f the Garibftldi Mine, wh affrded every facility, and my clleague, Mr. C. M. G. Friend, wh assisted bth in the field and in checking calculatins, many thanks are due.

10 EXPLANATION OF PLATE XXVII. Figs Calcite, Garibaldi Mine, Linsville, New Suth Wales. Frms: 0(01), b(1l20), y(8081), 17 '(4485), p'(1l21), ';'(4483), g:"(2241), m'(4481), JI (S 8161), e:(2132), K:(4151), f: (8412 1), U(6281). Fig. 5. Calcite, Hanging Rck, Nundle, New Suth Wales. Frms: b(1l20)j(1l22).

11 REC. A USTR. MUS., VOL. XV. PLATE XXVII. b b b 4 f f b f b T. RODGE SMITll, del.

12 EXPLANATION OF PLATE XXVIII. Calcite, Linsville, New Suth Wales, shwing crystals f the rhmbhedral-scalenhedrn (type Il) and prismatic habit.

13 REC. AUSTR. MUS., VOL. XV. PLATE XXVIII. G. C. CLUTTON, pht.

14 EXPLANATION OF PLATE XXIX. Fig. 1. Calcite, Garibaldi Mine, Linsville, New Suth Wales. A typical grup f the small rhmbhedral-scalenhedral (type I) crystals. " 2. Calcite, Hanging Rck, Nundle, New Suth Wales. Nte the prism faces cated with minute crystals f pyrite.

15 REC. AUSTR. MUS., VOL. XV. PLATE XXIX. 1 G. C. CLUTTON, pht. 2

16 EXPLANATION OF PLATE XXX. A view f the calcite dump at the entrance f the Garibaldi Mine, Linsville, New Suth Wales. This material has been rejected as unsuitable fr ptical purpses and cnveys sme idea f the size f individual crystals.

17 REC. AUSTR. MUS., VOL. XV. PLATE XXX C. M. G. FRIEND, pht.