Document jD64jBvEmnqMoBzKeaMgoXgp

GBP LOGICAL WESTERN AUSTRALIA. PRTST.TMT Ij ARY REPORT . The Blue Aabestoajaenosi ta of th e Hamerslev Ranges. By K. J. Finucane. (a) Introduction: - The oo-ourrence of "blue asbestos in.the Hamersley Ranges bias been known for some years, but during 1937-38 reports of a steady demand for this material resulted in consider able prospecting and development work being done through the ranges in the search for, and the production of, long fibre asbestos. The three principal occurrences are in Wittenoom's, Yampire, and-i>ale's Gorge. . Wittenoom* s Gorge is located 17 miles south-west, and Yanpire Gorge 3 miles south-east of Hulga Downs station which is. 180 miles south-east of Roeboume. Hale's Gorge is 9 miles east of Yampire. .^ .The asbestos (crooidolite) occurs in the form of cross fibre in veins' in flat bedded hematite-quart sites of the Nullagine 3 eries. . ' .' (b) Wittenoom*a Gorge:- In Wittenohmts Gorge the,asbestos fibre occurs in cliff faces at elevations of from 150 to 200 feet above the bottom of the gorge. The fibre is associated with~s... prominent market bed consisting of 6 inches of quartzite overlain by 10 to 15 inches of dolomite. Below the quartzite a consistent seam of crocidolite is exposed over a length of 1400 feet. Over this distance the length of the fibre varies from a thin thread up to 2 inches. Prom 4*.5 to 6 feet above the bottom seam - i.e. over a vertical range of 18 inches - there are several seams of asbestos in which the fibre varies from 0.1.to 1 inch. The aggregate thick ness of crocidolite in the 18-inch ribbon, i.e. including all seams, v aries between 2 and 3 inches. The asbestos formation also extends up a branch gorge for a distance of 15OQ feet. A sec on! ribbon from 14 to 18 inches thick and containing several seam3 of asbestos occurs about 30 feet above the marker. Individual seams of fibre vary from 0.25 to 1/75 inches, and tha aggregate thickness varies from 2.5 to 4.5 inches. Production from this gorge to October 1938 was approx imately 70 tons.' (c) Yampire Gorge:- The asbestos workings in Yampire Gorge extend over a total, length of approximately 3 miles. Two horizons are being worked - one in the upper portion of the gorgisi and a second horizon from 150 to 20^ feet stratigraphically above it in 2x1 the. lower Horizon the re ' is; a^de inite*>markerg^ehirabo ui|p 6 inches in. tfei cicggaa , conBistlng^of. wfaat^apjesrefcrtosbe aa^aJBorphassj form ofTblJie asbestos. Tlx* bWlkrorths*fibr#-:ooour-lielon^tiO-B(flc3B|^ -apd^onsiaW'of^a. ribbon uf grodr-qualltyinwhictr~t;hs:--lcng.tb ot-itbiigr^ fibre varies from 05 to 2 inches. Occasionally thin lenses occur above the marker. pour and: a Half feet below the marker, thera is a- similar bed. with which asbestoa fibre is. also associated. The-lower. Horizon has been worked over a totallengtH of 1500 feet. The upper Horizon may be traced for a distance of over 2 miles and ia associated with a marker bed similar to those deac ribed above. Most of the working? show from one to two. seams of fibre below this marker and two or three seams above it.. Individual seams vary considerably as to the length of f ibre and range from 0.25 to 1*5 inches. The aggregate thickness of crocidolite would probably average about 2 inches over 4 feet vertical height. (d) Dale's Gorge:- Workings in Dale's Gorge extend over a total length of 1.5-miles. Two definite limestone marker beds, each from 6 to 10 inches in thickness, may be traced through the gorge. These markers are 20 feet apart and the following asbestos seams are associated with them - a top seam ip feet above the upper limestone marker; Mahlberg's seam 15 feet below the upper limestone marker; a small seam of asbestos usually known as the "stringer** 7*5 feet below the lower limestone marker, and the main bottom seam 10 feet below the lower -limestone marker. In the upper portion of the gorge on Mahlberg's and Cotter's olaims, Mahlberg's seam has been worked over a length of 1600 feet. The f ibre varies in length from 05 to 2. j? inches. On"Reid's claim, which is located half a mile below Cotter's, the - main bottom`seam, has been worked;, the length of fibre varies from , 0.5 inches to 1*5 inches. Mahlberg's seam is impersistent in . Reid's, claim. Continuing down the gorge the,fibre of-the main . bottom seam is short where visible in the cliff faoes, and little .. work has been done for a length of 1200 feet. . Tyrer's workings are located towards the lower end of the gorge and extend along the main bottom seam for a length of 1200 feet. The fibre varies in length from 0.5 to 1.5 inches and. would probably average 1 inch. At the end of his benches Tyrer has carried out a little work on the top seam which shows lengths of fibre varying between 1.25 and 1.5 inches. ' *- (e) Genexral Summary;- A total of 400 tons of asbestos was won from these gorges in a period of a little over 12 months but excess, uncontrolled pxoduotion resulted in a fall in price and consequent curtailmentof operations. In Wittenoom's Gorge, there is an aggregate of from 3 to 4 inches of fibre over a vertical height of 6 feet, and with reasonably good market conditions this deposit could be mined. In Dale's and Yampire Gorges a consider able amount of f ibre could.be won by stripping the cliff faoes. Further deposits of asbestos are known to occur throughout the Hamersley Ganges. During 1936-37 Australia imported $486 tons of asbestoa valued at 87*117 While blue asbestos has some disadvantages when compared with white, the possible uses of the Hamersley Range f ibre deserve full investigation. It should be possible to supply a large proportion of Australia's requirements with asbestos from t hese deposits. . "'SETXir? , ------- --h~ -.*/-' ._ COPY OP -~............ .. '"* ......................... HEPOET 02f EAMEBSLSY BASSE BLUE ASSEST**^ BY " ' JUHa 3. jj'GXALL, ASSISTANT STATE MINING EHGlHEEB. 19th July, 1938. Hamerslev Bange Blue AsBestos. On my recent visit to the Hamersley Bangs district accom panied By Inspector O, Matheson, I made a detailed examination of the workings in Wittenoom Gorge, a plan of which., together with Bee Gorge, is attached. The plan is made from field notes prepared By Mr. Surveyor if, 0, Medcalf, who recently surveyed Mineral Claims 163s - 168e inclusive. . General -Ueacr intion. Ascending a steep declivity Eastward from about midway . along the Western Boundary of M.C. 167, the ledge on which the principal workings exist was reached at a point some 150 to 200 feet vertically.above the creek bed. The last 12 to 15 fset was ascended By scrambling up a cleft in the face of a vertical cliff. ; This ledge is almost perfectly flat and has been cleaned down to a width varying: from 3 to 20 feet. The asbestos here, appears in two horizontal seams, about 4 feet apart. The bottom seait oonsists of a practically unbroken ribbon of asbestos varying; in width from l--N to 2", all long fibre. This., can be followed fora distanoe of about 30 chains. The top seam is about 12 inches thick and con tains a number of veins of asbestos with fibre lengths varying from tr" to 1". Towards the Southern boundary of M.C, l63H the deep gorge appears to terminate abruptly in a cliff, halfway across whioh the wide ribbon has been vorked. After reaching this point it was neoe3Sary to descend to the creek bottom and scale, by means of a rope, a precipice about 60 feet high. Above this precipice'the workings were continued.on the cwestain side of the gorge, until the wide ribbon of asbestos disappears into the floor of the gorge, some three or four chains upstream from the cliff. At this point the upper lay er of thi3 seam has widened out to a thickness of 2 feet, with lentic ular veins showingfibre from -5# to 2B in length. In addition to the seamd escribed above, there exist two other parallel seams of aabestos, one about 20 feet above and the other 20 feet below the working seam. I` examined these at one or two accessible points, and the top seam showed fibre up to 2 inches in length, while the bottom one showed two ribbons about 2 feet apart with jjr to -f-** fibre. Xt is difficult to say whether .these seams woukL Be payaBle or not as they have not Been opened up sufficiently for a shUfcthxee c ox^^^^re^t'Caateatoa |rrtl3ft working aea*apaparS'.. to b< qualily i^aiytfhing than o th#Baatera.aide* " Seologio&l. * In the immediate vicinity of the- asbestos deposits, stratification of the rock appears to be as follows :- ` the - (Hameraley Bangs Blue Asbestos) * --, Tfosfcins- . Bolo mite Jasperoid Book Ironstone basing Asbestos Ironstone Casing Ba nied $ua rt z it e lb to 2 ft, 6" to 9h & to 1" lto 2* " to 1" Tile working to date has been confined to the main ribbon of long fibred material, as the hand dressing of the short fibres, would be too costly under the present primitive conditions* The .ironstone casing is very hard and very strongly attached to the fibre .and ; it is a day's work for a man to clean from 1 to 2 bags (of 100 lb.) by hand knapping. . Bo.actual underground work has been done. To date it , has been possible to remove the overburden and get at the* main asbestos ribbon. This method, however, has advanced in most . places as far as it compatible with safety, as it is not permiss ible to undercut the cliff to any extent. As it is probable that larger scale operations will commence in the near future, regular inspections will be neoess- ary to see that safety precautions are observed. ' If larger scale operations are to be undertaken, a cer tain amount of experimental work will be neoessary in order to finally decide on the best and most economical met hod of mining* Although to all appearances the deposit seems to be enormous, yet it is not known how far the asbestos extends into the face of the cliffs, and it is impossible at this juncture to give even an approximate estimate of reserves. ' It is certain that, in mining, it will be necessary to leave a large proportion of pillars. In this the operations will bear some resemblance to coal mining. The proportion to be left cannot be estimated until such time as the deposit is opened up, and the nature of the ground, tested. Hany of these pillars may possibly be eventually won by packing behind them with the mullook which will form the greater part of the rock broken during mining operations. Until 3ome experimental work is done, the quantity of 1o + -i ->------------- - - nefore ^ser;y^jpto any- contract % suBply^jp tea-. to-Tjon^aunerab- aejc^taii^amounteof. ilo aking~q iarr: o^ervw aicuxe' regularity; of|pro4hctif ..mJSjrsT Ayerjtv Certain fgrad fbg testa will be required to aaoor^aiitlt percentages'of different length, fibre that oan be anticipated*- and the treatment of rock mined from development would be, I think the only reliable indication of the amount of fibre In the blooked out ore. . The method, of handling ore and materials in this partic ular locality would doubtless be some sort of flying fox,- to.- trans port the ore to the plant and material to the miners on the cliff side. ' ' v Transport dll also be an initial problem. At present donkeys are used to transport the bags of fibre to a point out side the gorge whence it oan be handled by motor transport, but the provision of a passable road will be a necessity if major operations are to commence. Government assistance will doubtless be sought later in regard to this matter. . .xhe Australian Blue Asbestos Compaiy Jsf.L. has purchased ft. Us. 163*S 164 , and 167U and. have taken up 2I.C. 169* and are considering commencing immediate operations. It is not known at present what their exact intentions are, but -in my opinion they would be wise if for the present they considered themselves in the light of a development and exploration company, installing a small plant for the treatment of their development ore, and devel oping and blocking out future ore'reserves whilst making tentativ* marketing arrangements for the future. - Although it is impossible to make an estimate of reserve es, I am confident that there is sufficient fibre in this gorge *. alone!to warrant preparations for large scale mining operations, provided that a market can be found for the product at reasonable prices. .. X also visited Yao&ire Gorge, but owing to rain setting in, which made climbing very dangerous, and promised to make the road to Mulga Downs impassable, I returned without an examination of this or Dale Gorge. From descriptions received, however, and samples of asbestos seen from these two localities, I have no r eason to disbelieve that the deposits there are similar to that . at Wittenoom Gorge. Good floaters of long fibre have also been found, as far a3 30 miles Eastward from Yampire Gorge, which leads to the belief that there are other as yet undiscovered deposits in the Hamer3ley Hange. STAR T*. COPY BOX NO./FILE DRAWER NO. - INITIALS DATE SEGMENT NO. ' P SIGNIFICANT NOTES auiL B yXmv/(fe -->