Thursday, 31 December 2015

GADEN’S LODE GULF ROAD, EMMAVILLE

GADEN’S LODE GULF ROAD, EMMAVILLE
This is another old mining area I haven’t visited, or if I have I didn’t know its name and it has faded from memory. There are quite a few mineral deposits in the area, of which Gaden’s appears to be the best known. It has been the site of several Emmaville Gemfest field trips and I am indebted to Jewellery Pirate for information and photographs from his Blog.

If you examine the satellite image from Google Earth you will see the site of Gaden’s Lode marked in pink in the centre (source: Mindat). The most notable feature on the image is the joint pattern in the Mole Granite which occupies a broad swathe of country across the centre. Observe how these joints disappear around Torrington/Torrington State Forest where the granite is still covered by part of its original “roof”. This is the Torrington Pendant of older sedimentary rocks. The joints have controlled the deposition of ore bodies both in the granite and in the adjacent areas where the granite is still concealed by these older rocks.

The map was extracted from the Grafton-Maclean Metallogenic Map; the numbers locate the various mines and prospects. I know that some of the numbers are hard to read and I can’t interpret them all, but here is a list of those I can (lowest to highest) with some information (from Mindat) about each, where there is any. The names in brackets are alternative names or nearby mines/prospects.
0300 Chinaman’s Gully Sn vein (Murphys lode; Suicide tunnel). Operated as underground workings, adits, shafts and shallow pits. Production from 1878 to 1965. Chinaman’s Gully alluvials: Dredging operations until the late 1960s.
0312 Gaden’s Lode Sn W Cu U monazite vein (Gaydens lode; Garths lode; Garths wolfram lode; Garths uranium lode). Operated as underground workings, open cut, shafts, adits and shallow pits from 1877 to the late 1960s.
0313 Stormer’s Lode Sn fluorite Cu U vein (Garths lode; Garths wolfram mine; Garths uranium mine; Gadens uranium mine; Gadens lode; Gaydens lode; Gardens lode). Operated as shallow pits, open cut, shafts and adits 1913 to 1954.
0314 Garth’s Lode Sn vein.
0315 Heiser’s Lode U Sn vein (Garths lode; Fish & Chips). Operated as shafts and pits 1877 to 1968.
0330 Stevens and Charlton vein Sn W (Stormers reef). Operated as shafts and shallow pits 1887 to 1970.
0331 Mineral Tunnel Sn As Zn Pb vein. Operated as adits, shafts and open cut 1889 to 1893. Also alluvials.
0332 Suicide Tunnel Sn vein. Operated as underground workings, shaft and shallow pits 1889 to 1893. Located slightly West of Mineral Tunnel workings.
0329 McKinnon’s Reef vein Sn W As Cu Bi (Paradise lodes; Blue lode; Murphys lode; Garths tin lode; Mineral lode). Operated as underground workings, open cut, shafts, adits and shallow pits 1878 to 1950.
0754 Small prospect Sn vein.
0755 Mineral tunnel alluvials Sn placer.
0757 Minor Lode Sn vein.
0758 Hill Crest deposit beryl pegmatite. Operated as shafts from 1890 to 1890. (This may be a wrong identification)
Ore minerals in Gaden's Mine (photo Jewellery Pirate)
There are three principal types of ore bodies in the area: tin (Sn) veins, which consist largely of quartz and cassiterite, polymetallic veins which contain a wide variety of sulphides such as pyrite, chalcopyrite and arsenopyrite as well as cassiterite and wolframite, and pegmatites, which frequently contain fluorite, topaz, tourmaline and beryl as well as some of the ore minerals already mentioned. All types occur in this location.
Where is this mineral collectors’ paradise? You are 60 years late for the easy pickings, but if you are diligent in searching out the locations listed above (not forgetting the alluvial deposits) you are sure to find something of interest.
The area lies between Flagstone and Paradise Creeks. Proceed along the Gulf Road from Emmaville.  A useful reference is Geo-Log 2011 – a publication by the Amateur Geological Society of the Hunter Valley, beginning on page 42 (here). (missing - try searching for it on Google).The whole publication is worth reading, as are the other Geo-Logs in the series.
Dump at Gaden's Mine
The track to Gaden’s branches off to the right just after the Torrington State Conservation Area is reached. This is after you have crossed Flagstone Creek. Naturally the track condition is going to vary according to weather conditions but it’s unlikely to be drivable by 2 WD vehicles. Searching DIGS (if you can find it) will produce many reports on the area which are easily downloaded.

Of special interest are the references to radioactive minerals from some of these mines

and prospects.. During and after World War 11 there was a lot of prospecting for uranium minerals in particular when it was commonly believed that the world would soon be using nuclear energy as its major power source, as well as for making nuclear weapons. (The extensive uranium deposits in the Northern Territory and South Australia had not then been discovered.) The publication “Radioactive Prospects in NSW” (here) dates from this time. It should be noted that monazite, which contains the radioactive metal thorium, is also found in this area.

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Friday, 11 December 2015

THE ASHFORD LIMESTONE CAVES

THE ASHFORD LIMESTONE CAVES
From the Ashford Tourism website
The Ashford limestone caves are located about 20km north-west of the town of Ashford, between Inverell and the Queensland border. What was once a crown reserve (set apart in 1915) is now part of the Kwiambal National Park (pronounced Kiamble), best known for the spectacular MacIntyre Falls, near which is a delightful camping area at Lemon Tree Flat. Picnic and toilet facilities are also provided at the caves.


These caves are not in the same league as the well-known show caves at Jenolan, Wombeyan and Yarrangobilly, in fact there are very few speleothems (decorations) to be found. What you will find is bats, guano (bat droppings) and a sense of adventure as you explore the unknown (to you) cave system. If you would like to read a fascinating account of “An Excursion to the Severn River and the Wallangra Caves” dating from 1892 (here) you will appreciate that some things have not changed, but others have considerably. The most notable change has been the removal of thousands of tonnes of phosphorus-rich guano for use as fertiliser, a process that was underway long before the reserve was established and continued as late as 1967.


There is a lot of information available about the geology, history and biology of Ashford Caves. I have given a list of downloadable resources at the end of the blog.
The caves have been formed in a bed of Lower Carboniferous limestone (probably, though estimates range from Devonian to Permian), which has been considerably deformed and largely converted to marble. It contains marine fossils (mainly crinoid and coral fragments), but remember that this is a National Park (no collecting allowed) and beyond the fences is private property, which limits the collecting possibilities to road reserves outside the Park. As the limestone has been traced for more than 10 km there must be some accessible outcrops, since the road basically follows the strike of the limestone. If you locate specimens of interest, tell us about it by adding a comment below.
There are a few typical karst features, notably the dolines where caves below have collapsed. You
Calcite formations 1999 (my photo)
might also come across solution grooves, widened joints and potholes as you walk around the limestone hill.
Early references note the existence of two main caves. The removal of so much guano has lowered the cave floors considerably and the two caves are now joined, making a through trip possible. There are a few other small caves but none appear to have much potential for new discoveries.
Three species of bat frequent the caves: Miniopteris schreibersii (the eastern bent-wing bat), Rhinophilus megaphyllus (the eastern horseshoe bat) and Eptesicus pumilus. Most of those you will see are bent-wing bats. Do not disturb them by making loud noises or shining lights on them. During the summer breading season, do not enter the main cave at all.
Bats 1999 (my photo)
The guano had accumulated to a depth of several metres in the most favourable places. A typical chemical analysis reveals that it contains 5-10% of phosphorus. Especially during the Second World War, when supplies of phosphate from Nauru and Ocean Island were cut off by the Japanese (both islands were occupied by them) alternative supplies were identified all over Australia. Ashford Caves was one of these.
Some useful references.
The Ashford Tourism site (here); (missing: you will have to search for it)
Guide to NSW Karst and Caves pp 10-11 (here); (missing. Try DIGS website or search Trove)
DIGS website (needed for the listings below) here. (missing - please let us know if you find it)
Annual Reports of the Department of Mines, New South Wales, for the period 1939-1945 (DIGS reference R00001425). This includes cave maps and guano analyses (beginning on page 82).
The Limestone Deposits of New South Wales (DIGS R00050689). An excellent report from 1919 giving information about all the then known limestone deposits.
The Limestone Deposits of NSW (1986) Lishmund, Dawood and Langley (DIGS R00056921). A modern, revised version of the above.
Geological Age of the Ashford Caves Limestone (DIGS R00019198). Report by Raggatt and Booker, 1940.
A Report on a Visit to the Ashford Cave, Northern NSW (DIGS R00023521). 1973 Anonymous.


https://johnsbluemountainsblog.blogspot.com/2013/12/links-to-all-blog-entries-and-relevant.html All Blue Mountains blogs and videos
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Friday, 20 November 2015

SPECIMEN HILL, THE GULF NEAR EMMAVILLE NSW AUSTRALIA

SPECIMEN HILL, THE GULF, NEAR EMMAVILLE 
NSW AUSTRALIA
 
The mine location is marked at top centre (Mindat)
I’m sorry to say that I have never visited this old mining area, which is along the Carpet Snake Creek fire trail, off the Gulf road, north-west of the New England mining town of Emmaville. It is one of many hundreds of mineral deposits in the area, mostly discovered in the period 1875-1900.
Mindat (here) provides the following location information:
Latitude & Longitude (WGS84):
29° 16' 35'' South , 151° 31' 4'' East
Latitude & Longitude (Decimal Degrees):
-29.2763888889 , 151.517777778
Latitude & Longitude (Degrees plus Decimal Minutes):
-29° 16.5833333333', 151° 31.0666666667'
The workings are on the right hand side of the fire trail about 1km from the Gulf road turnoff, which is on the right not far after the ford across Paradise Creek. Be aware that the access road is not likely to be OK for 2 WD vehicles.

Here are some useful references: Geo-Log 2011 page 64 (here). Geo-Log is an e-zine put out by the Hunter Valley Amateur Geological Society and the whole of it is packed with useful information.

The Mindat article also provides a list of reported minerals from this location: Beryl, var Emerald, 'Biotite', Cassiterite, 'Chlorite Group', Epidote, 'Feldspar Group', Fluorite, 'Monazite', Muscovite’ var: Sericite, Pyrite, Quartz, 'Tourmaline', 'Wolframite'. The quote marks imply that that a mineral group rather than a precisely named mineral species is intended. (The blue colour has to do with links in Mindat which I haven't been able to change.)
Quartz crystal tips (Jewellery Pirate)
Also noteworthy is the inclusion in the article of a photograph of an emerald crystal, which is so typical of those found at the Torrington emerald mine (Cow Flat) that I am certain the specimen came from there rather than from Specimen Hill. To my knowledge, no-one has recorded finding emerald or even beryl at this place. I will gladly change this blog if someone can tell me otherwise.

Note that the Grafton metallogenic map (an extract is shown below) locates Sim’s Deposit (EA0336), Farmer’s Deposit 
Enlarged from the Graton Metallogenic map
(EA0338), the Breakfast Creek Deposit (EA0022) and the Breakfast Creek Alluvials (EA0783) in this area. Several of these (like Specimen Hill itself (EA0335)) are lodes, the others are alluvial. This means that if you are visiting the area, seek out these lesser known spots and in particular do some gem sieving in the gullies – topaz and monazite as well as cassiterite and quartz crystals could be waiting for you. Pretty Gully is to the west of Specimen Hill, Breakfast Creek is on the eastern side. Both contain alluvial cassiterite.

The geology of the locality is well described in “The Mineral Deposits of New South Wales” by Markham & Basden (1974), downloadable from DIGS here (doesn't work 2024), reference number R00037944. The quote following is from page 371.
“Two or three kilometres to the west, (ie of the Paradise lodes ed.) on the summit of a high hill, is the Specimen Hill (also known as Mt Garth or Mills) lode (GR 45493722 Grafton 1:250,000). Workings, consisting of cuts, shafts to 20m, and adits, extend for 300m. Thin, tin-bearing veins run in several directions. Some of the vein material is very siliceous, consisting of granitoid quartz (clear, white and brown grains) with scattered vughy inclusions containing tourmaline and minor cassiterite and epidote. Patches rich in chlorite are also present. Drill holes at Specimen Hill (Rasmus 1972 a,b) intersected up to fifteen thin veins, but the cores contained no visible tin. Production is not known.”
 
The earliest reference I can find to mining at this place is in 1910; despite much prospecting work nothing substantial seems to have been discovered then or since. The reference to Rasmus’s report on drilling in 1972 is part of ongoing prospecting from 1971 to at least 1977. From the mineral collecting point of view, I found the comments in a report dated 16.11.77 the most interesting (image opposite). This is the last mention of the site I can find in DIGS.
Candle crystals - Paul Hayes photo
What are you likely to find at Specimen Hill? Quartz crystals for sure, including the fascinating “candle crystals” (which look like they have had wax poured over them); crystal groups; possibly cassiterite crystals and probably schorl tourmaline, epidote and chlorite – if you are lucky, several of these in the one specimen.
Quartz crystal group - Paul Hayes photo
I have no photos of my own of Specimen Hill; I would like to acknowledge those I have copied from  Paul Hayes’ “Wild Frontier Crystals” site (here).(Can't be found)



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Wednesday, 16 September 2015

THE GULF FLUORITE MINE NEAR EMMAVILLE, NEW ENGLAND DISTRICT NSW AUSTRALIA


THE GULF FLUORITE MINE NEAR EMMAVILLE, NEW ENGLAND DISTRICT NSW AUSTRALIA

The Gulf Fluorite specimen 100mmX53mm Clifford Collection
Fluorite (calcium fluoride, Ca F₂), also called fluorspar) is found in many places in New England, but the area north-west of Emmaville, near the margin of the Mole Granite, known as The Gulf appears to be the place where there are the most reported occurrences. Of all of these, only that commonly called The Gulf Fluorite Mine (alternatively known as Shepherdly’s Mine or Shepherdly’s Fluorite Mine) came even close to being an economic source of the mineral.
There are a number of newspaper reports from February 1919 in Trove, near enough to identical and probably copied from a press release.
Most geological information also comes from this time as investigations were made into the economic possibilities of the mine. The remote location and the limited amount of mineral available soon led to its abandonment. However, the variety of minerals to be found there has made it a popular collecting locality over the years, so whenever access is possible (it is private property, so keep away at other times) there are always quite a few people keen to make the trip.
Minerals found at the Gulf Fluorite Mine
Field trips associated with Minerama (Glen Innes) and Gemfest (Emmaville) are the most likely ones that you can go on, so check out their websites for information (Google them and you will soon find them).
I have visited the place only once, in preparation for the 1997 Minerama field trip and the theme booklet on fluorite which appeared that year. You will find a copy of the book in this Blog (February 2024). We had quite a few problems with the book in 1997. Most of the colour plates are unsatisfactory and, to make matters worse, they aren’t all on the pages shown in the table of contents. Not only that, but I lost my copies of the original photos when I had
Heide Klingbeil and John Paix examining a chlorite specimen
computer problems in 2014. My most abiding memory of that reconnaissance is the large number of needle-like pale green beryl crystals scattered on the dumps. Hopefully there are still some left for present-day collectors!
In spite of these defects, the content was good and I have copied the section dealing with The Gulf Fluorite Mine into this blog. Here it is, with a description of the references if you wish to consult them. I have made a few very minor corrections to the original text.

“The only deposit in New England which produced fluorite on anything approaching a commercial scale is that at the Fluorite Mine, otherwise known as Shepherdly's Fluorite Mine. It is on ML
Mine locations at The Gulf (from the Mole Tableland map)
10, 22km northwest of Emmaville, Parish Muir, County Gough; GR 44783735, Inverell 1:250,000.
The mineralization at the Fluorite Mine occurs as small lenticular shoots in "shrinkage" veins in a coarse-grained granite. These were called "pipes and vughs in the granite" by Raggatt.
Reference 28, p 13. “The lode strikes 285⁰ and has an average width of 0.6m.The vein is made up largely of fluorite, sometimes in large masses (up to 0.6m of pure fluorite in places) with abundant quartz, feldspar, chlorite and greisen. Sulfides of arsenic, copper and zinc and a little beryl are the main accessory minerals. This deposit has been worked in the past for wolframite and fluorite. One main shaft was sunk in 1919 following a fluorite-rich ore shoot, 2m in diameter, which pitched steeply to the west. Another shaft 3m deep was sunk on fluorite 24m to the west of the old shaft. A sample of several tonnes of hand-picked ore contained 93.1% CaF₂. The fluorite is commonly extracted in large, bright-green masses, free from impurities. Both the fluorite and wolframite are very pure and the fluorite could be used for enamelling purposes. The remoteness of this deposit and the small reserves of ore make further production unlikely…. Total recorded production is 296 tonnes of which 203 tonnes were produced in 1919.”
Reference 25 p 372. "Fluorite has been won from what may be a pegmatitic vein or shoot in the
Cover photo from the 1997 Minerama book
granite…. It strikes at 105⁰. M, and is 0.6m wide along drives and 2m in diameter in a shoot which pitches steeply westerly..... It is of interest that the prolonged exposure to the atmosphere of fluorite on the dumps has resulted in a loss of colour."
Smith (Reference 29 p 76) also refers to the Fluorite Mine. "There are several localities in which the fluorite is found of the same quality. It is sometimes roughly crystallised, very translucent, and always of a rich green colour, except when associated with the copper ore, when it is less distinct in colour. The locality in which it is found is about three-quarters of a mile west to 3 miles north-west of the Gulf. ... Several inquiries were recently made for pure fluorite for purposes for which inferior material would be unsuitable, and as samples had  been forwarded to Mr. Card (Ed. - the N.S.W. Government Analyst), inquiries were readily satisfied as to quality. This has resulted in the mining of considerable quantity - over 100 tons - and the establishment of the enamelling industry in Sydney."

Front cover specimen with fluorite necklace
According to David (Reference 11 p 111), “Gaden's Lode, the furthest west of the above-mentioned lodes (Ed. - the Gulf Lodes) is situated in portion 33, parish Muir, county Gough. The vein is from 2 to 3 feet wide, and strikes 40⁰ east of north and west of south, dipping about 82⁰ south-easterly. Veinstone chlorite and quartz with vughs filled with purple fluorspar. The walls are not defined, the veinstone merging into a very quartzose ternary granite, becoming less quartzose at a distance from the vein."
Reference 10 p 54. “Davison's Lode. West of Gulf Creek, Parish Muir, County Gough. Strike N.E. Shaft sunk about 20 feet in chloritic quartzose lodestuff containing wolfram, copper pyrites and fluorspar."
Reference 10 p 59. “Hutton's Wolfram Lode. West of Gulf Creek, The Gulf, Parish Muir, County Gough. Strike N. 60⁰h E. Opened for a length of about 4 chains. Fluorspar conspicuous, also chalcopyrite. Occurs in chloritic veinstone with crystalline quartz in vughs and small veins. Width from a thread to 2 feet. The Gulf Stream Lode. (Portion 60, Parish Land’s End, County Gough; GR 450374, Inverell 1:250,000) is a fissure vein up to 2m wide, but averaging 0.6m. It was worked for tin. Like the other lodes in The Gulf district, fluorite and wolframite are both present in the vein, which consists mostly of quartz, chlorite and decomposed felspar. Balmain and Rumsby’s mine is located at GR 44883721, Inverell 1:250,000.”
Reference 25 p 372 states that "Minerals present in the lode include major chalcopyrite with wolframite and pyrite, and minor arsenopyrite, scheelite, galena, beryl, fluorite and tourmaline."
Reference 10 p 66.”Rumsby's Lode, south-west of the Yankee Tin Lodes, The Gulf, Parish Muir, County Gough. ... The pipe measured 10 feet by 8 feet in its strongest part. The veinstone is chloritic and soft. The wolfram occurred in masses of great purity, accompanied by large bunches of rich green fluorspar, and lesser quantities of mispickel and copper pyrites."
Garths Lode (ML 4 in Portion 11, parish Flagstone, County Gough; GR 45833706, Grafton 1:250,000) is a complex and interesting ore deposit. Reference 23 p 15 states that it is "a fissure lode about 1m wide in granite about 50m from the sedimentary contact.  Cassiterite, biotite, chlorite, ferberite, chalcopyrite, arsenopyrite, tourmaline, monazite, topaz, quartz, green and purple fluorite, and torbernite are present. The deposit was worked for tin."
Reference 25 p 371. “Garth's or Gayden's lode consists of the usual quartz-chlorite with cassiterite,
Specimen from The Gulf with fluorite carvings
chalcopyrite, minor green fluorite and rare monazite and torbernite. Strike is 013⁰, dip is near vertical, known length is 200m, and average width is 0.75m. Heisers Lode (ML 68 in Portion 11, Parish Flagstones, County Gough; GR 458370, Grafton 1:250,000) is a greisenous lode adjacent to Garth's Lode. According to Reference 23 it "is developed within siliceous granite at the granite/metasediment contact. Cassiterite, ferberite and pyrite occur in a gangue made up of quartz, chlorite, chrysocolla, stilbite, biotite, magnetite, tourmaline and fluorite, with traces of torbernite. This lode was mainly worked for tin."
10. (1912). The Tungsten Mining Industry in New South Wales. Miner. Resour. geol. Surv. N.S.W.15 102 pp.
11. DAVID T.W.E. (1887). Geology of the Vegetable Creek Tin-Mining Field, New England District New South Wales. Mem. geol. Surv. N.S.W., Geol. 1 169 pp.
25. MARKHAM N.L. and BASDEN H. (Editors) (1974). The Mineral Deposits of New South Wales. Geol. Survey of N.S.W. 682 pp.
28. RAGGATT H.G. (1924). Asbestos, Emery, Fluorspar, Fuller's earth, Graphite, Phosphates, Talc and Soapstone. Bull. geol. Surv. N.S.W. 14.
29. SMITH G. (1919). The Occurrence of pure fluorspar in New South Wales. A. Rep. Dep. Mines N.S.W. for 1918.
There is more recent material in the various metallogenic maps and surveys (Mole Tableland, Inverell and Grafton) which would help you to locate the above mentioned sites and others mines and prospects in the vicinity. These are all downloadable from DIGS, as are the references listed above.
Happy collecting! It would be of benefit to all future readers of this blog if you could add a comment telling of your collecting experiences at this interesting old mining locality.
Mindat record of the Gulf Fluorite Mine here. 
Geological Survey of NSW report on Fluorite (1973) here.

https://johnsbluemountainsblog.blogspot.com/2013/12/links-to-all-blog-entries-and-relevant.html All Blue Mountains blogs and videos
Song Studies. Bible studies based on hymns and songs
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