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Showing posts with label pipe. Show all posts
Showing posts with label pipe. Show all posts

Monday, 11 March 2024

KINGSGATE MINES Part 4

DESCRIPTION AND LOCATION OF THE MAIN PIPES
For much of this information, we are indebted to the geologists of the NSW Geological Survey, in particular to Mr. E.C. Andrews, whose work "The Molybdenum Industry in New South Wales" was published in 1916. To avoid any confusion with names and the numbering system, it needs to be understood that the numbers appearing on the map in Andrews' report are those assigned by Mr. W.H. Yates to pipes under his control in 1915. Numbers appearing as part of names refer to the Portions of Parish Kingsgate and therefore relate to the original mining leases of the 19th Century. Pipes under Sachs' control at that time or under the control of other miners and prospectors were either not numbered at all or assigned letters. The descriptions which follow treat the pipes essentially in order from the north, Portion by Portion.



Portion 24.
1. Known as “Quinn's Find” - a prospect only.

Portion 6. (originally leased by Feeney, Rush and Say in 1879)
2. Dips at 1:2; a branching pipe, an unimportant producer.

3. Prospect only.

4. Small vertical pipe.

Portion 1.
47. The “Swamp Blow”. A prospect north of the present main road in a swampy area.

5. Usually known as the "One and Nine" from its location on the portion boundaries. This pipe has been an important producer of both bismuth and molybdenite and is apparently the site of Quinn's discovery of "sulfur" in 1877. The upper part of the pipe has been mined as an open cut which now lies quite close to the main road. In cross section, the pipe varied in diameter from 1 to 8 metres. It has been mined to a depth of about 85 metres, and consisted essentially of a gangue of well crystallised quartz with rich deposits of bismuth and molybdenite. Vughs lined with crystals of white and black quartz crystals up to 1.2 metres in length were found. Several branches of the main pipe were noted at depth.


6. Prospect only.

Portion 9.
7. The “Water Shaft”, “Tin Shaft” or “Tin Show”. This was the second pipe to be prospected in 1872. Small quantities of cassiterite were found in the quartz. The pipe, which is nearly vertical, has been prospected to a depth of 12 metres.

45. Known as "Jack's at Home". Prospect only.

46. Prospect only.

Portion 100. (Originally in four blocks, leased by Quinn & Ferguson in 1879)
9. “Bill Miller's Hole”. A fairly large but poor pipe prospected to a depth of 10 metres.

40. “Jubilee Pipe”. A surface prospect only.

48. Prospect only.

10. The “Wolfram Pipe”, “Wolfram Blow”, “Old 26” or “Little Tunnel”. This particular pipe was the one originally prospected in 1872. While it contains a little cassiterite in a massive white quartz gangue, the pipe is notable for the quantities of wolframite and arsenopyrite it contains along with the usual bismuth and molybdenite. Both can be readily found on the dumps. Initially mined as an open cut, it was later worked by a tunnel to a depth of 30 metres. The maximum diameter reported was 3.7 metres. Commercial quantities of wolframite were mined here in 1950-52.

31. Prospect only.

37. “Tom Key's Hole” or the “Chimney Shaft”. A fairly small, steeply dipping pipe worked to a depth of over 45 metres.

8. The “Black Shaft” or “26 East”. This large pipe produced substantial quantities of ore in the early days, when it was followed down to a vertical depth of over 40 metres.

11. “Mick's Shaft”. A vertical pipe of moderate dimensions.

12. Prospected at the surface only.

35. The “Granite Shaft”. Instead of the usual quartz, the molybdenite and bismuth were found here in a gangue of granite, in which the felspar was largely sericitised. The pipe, a moderately deep one, dips steeply and branches into two at depth. It has been mined to a depth of at least 40 metres. For the first 30 metres, the ore occurred in the granite itself. One branch continued as granite, the other was a typical quartz pipe.

36. Known as the “25 Northwest No.2 Pipe”. It is small and has been prospected to only a shallow depth.

34. The “Mount Morgan Pipe” is a large pipe (up to 7.6 metres across) located at the highest point on the plateau, on top of a rocky knoll on the left of the access track. It dips quite steeply to a depth of more than 50 metres below the surface. The workings are still fairly accessible but should not be entered.

32. The “25 West”. A surface prospect only.

13. The “25 North”. This pipe has been one of the largest producers of both bismuth and molybdenite at Kingsgate. It has been followed down to over 150 metres from the surface, at first at a fairly shallow angle, then more steeply when it became necessary to sink a vertical shaft to facilitate mining. The pipe branches at several places. The quartz gangue was in places marked by large vughs which were lined by huge quartz crystals. The dumps of this mine yielded quantities of radio quality quartz during World War 11.

14. The “Old 25”. This was another pipe first mined as an open cut and later mined underground. Mined to a depth of 76 metres, the Old 25 was one of the largest pipes on the field. A haulage tunnel was driven into the base of the workings to facilitate access. Most of the workings are still accessible but should not be entered. The mine lies to the right of the access track and its dump also yielded crystals during the war. More recently the dumps have yielded many fine mineral specimens.


38. “25 South No.2”. A fairly shallow prospecting shaft.

33. “25 South”. Similar to its neighbour.

15. “Weidmeyer's Cutting”. A vertical pipe of moderate dimensions mined to a depth of 30 metres.

16. “Martin's Hole”. A small vertical pipe.

Portion 27.
17. Prospect only.

Portion 28.
18. “Schoolhouse Blow”. Prospect only.

19. “Magazine” or “Windlass Shaft”. Prospect only.

21. “28 South”. Prospected on the surface only.

Portion 42.
20. Prospect only.

Portion 49.
22. Prospect only.
Portion 40. (Yates' original lease of 1880)
23. “Forty North”. This was another of the very productive pipes. It was originally abandoned because of its poor showing on the surface, but rich bismuth ore was later discovered in it by the discharge of water from a race eroding the weathered granite. The pipe descends in stages to at least 30 metres below the surface. The quartz gangue was at times either massive or cavernous, containing grey and black crystals. Both bismuth and molybdenite were mined in large amounts.

24. “Forty” adjoins Forty North to the south. The surface rubble of white quartz yielded much bismuth which was followed downwards in an open cut for about 6 metres. In later years the pipe was followed vertically for about 90 metres, continuing to produce quantities of bismuth and lesser quantities of molybdenite. The quartz occurred in massive form and as large white and smoky crystals.

39. Prospect only.

41. “Road Block Pipe”. A small unimportant hole about 10 metres deep.

42. Prospect only.

25. “Forty South”. Another small producer about 20 metres deep.

51. “The Reef Blow” is a pipe with three main branches, initially mined in a gently inclined tunnel which later became vertical. Both bismuth and molybdenite were produced.


Portion 41.
44. A small pipe mined for quartz in 1942.

26. “Jim Marshall's Hole”. A surface prospect only.

27. Prospect only.

28. Known as the “Arsenic Blow”, “Arsenic Shaft” or “Hagen's Tribute”. This is another of the pipes known from the early days of the field. Like many of the pipes, it was first mined as an open cut but subsequently underground as the dip of the pipe changed from vertical to nearly horizontal and vertical again as the pipe was followed down. The pipe was approximately 3 metres in diameter and was traced downwards for about 60 metres. The gangue was, as usual, quartz - sometimes massive and frequently cavernous. Some of the vughs encountered were more than 3 metres long, lined with large quartz crystals. In 1942 the old shaft was dewatered and the mine worked again specifically for quartz crystal. The Arsenic Shaft appears to have been the main producer of crystal at Kingsgate.

43. “Christie's Blow”. A prospect only.

ML 45 and Adjoining Leases.
“Monkey Shaft”. Described as more of a vein than a pipe, it was worked to a depth of about 13 metres. At depth the vein gave way to a true quartz pipe. This deposit was among several in this corner of the field tested for crystal in 1942.

“The Wet Shaft”, “Water Cut” or “Wet Cut”. This pipe was mined to a depth of about 60 metres, producing good yields of both bismuth and molybdenite. The quartz gangue was noticeably cavernous and the dumps were turned over for crystal during the war.

The “Old 45” or “Sachs' Pipe”. This pipe is the most famous of all those at Kingsgate because of the exceptional masses of molybdenite extracted from it. It probably produced more mineral than any other pipe on the field. It was first worked for bismuth but was then abandoned because of the high molybdenite content of the ore which made it difficult for the miners to produce a pure bismuth concentrate. In 1902 the mine was reopened by Mr. Valentine Sachs, who soon discovered a large vugh more than 15 metres across. This extraordinary cavity was lined with massive quartz and molybdenite crystals. One piece of solid molybdenite removed was said to have weighed about 1 tonne. After producing many tonnes of ore, Sachs evidently lost the course of the pipe and therefore sold the mine. The new owners subsequently discovered that the pipe had constricted to only 50 cm in diameter. They followed the pipe downwards, but no further bonanzas of ore were located. The total length of the workings approaches 100 metres, most of which is still accessible.
“Goodwin's Pipe” was mined to a depth of about 60 metres at an angle of about 45o. Good yields of bismuth and molybdenite were obtained. Because access was from a cutting just above creek level, the workings are now completely flooded. Calcite cementing pieces of quartz pipe material was a feature of this pipe.
Portion 44.
29. “The Hard Blow”. A small pipe mined to only a shallow depth.

49. Prospect only.

30. “Sachs' Folly”. Prospected on the surface only.

50. “Nield's Blow”. Prospect only.

ML 90 (formerly “Sachs' Prospecting Area”.

F. This pipe, also known as “Potter's Claim”, yielded fairly large amounts of ore.

G. Known as the “Reef Blow”. (Not to be confused with Pipe 51 also of that name.) This is another of those pipes which appeared more like a vein in places. It produced good yields of molybdenite.

H. “The Giant Blow” is well known for the very large doubly terminated quartz crystals found in the gangue. These were first located right at the surface. The pipe produced quantities of bismuth and molybdenite from an open cut which was then followed down into underground workings. These are still accessible.

I. No details available.

J. No details available.

ML 55 (formerly “Pauline Speckhardt's Lease”
A. A small pipe containing both bismuth and molybdenite in minor quantities.

B. This fairly small pipe produced many tonnes of rich ore containing both metals.

C. This pipe, followed down for more than 30 metres, produced bismuth in fair amounts.

D. No details available.

E. No details available.

Mines South of Yarrow River.
From Kingsgate, the boundary between the Permian metasediments and the granite has been traced southwards for many kilometres. Ore bearing pipes have been found in two areas across the Yarrow River not far from the Kingsgate pipes and obviously related to them.

Portion 19, Parish Yarrow.
The “Dodger Claim” (“Maurer's Claim”) includes 4 pipes near the granite boundary.
1. Yielded good quantities of both bismuth and molybdenite. The pipe is relatively large by Kingsgate standards.

2. A smaller pipe with smaller quantities of molybdenite.

3. Another pipe of moderate size followed down for at least 20 metres. Good quantities of both bismuth and molybdenite were mined along with large amounts of well crystallised quartz, generally smoky.

4. Similar to the previous pipe.

Portions 20-23.

More pipes have been prospected in this area, a little north of the Pretty Valley Road.

Saturday, 9 March 2024

KINGSGATE MINES Part 3

THE GEOLOGY OF KINGSGATE

The casual visitor may overlook the intimate relationship between the ore bearing pipes and the granite/metamorphics contact, but the miners were well aware that the ore bodies were always found within the granite and never more than a few hundred metres from its margin. That this is more than a co-incidence was borne out during mining when it was often found that the pipes dipped into the earth more or less parallel to the contact.

It will be necessary to examine briefly the geological structure of the district to understand the origin of the mineral deposits. The rocks throughout New England reveal a complex history of marine and nonmarine sedimentation, explosive volcanic activity and widespread intrusion of granitic magma. This is consistent with what is found today along growing continental margins, where marine sediments are subducted beneath thicker continental crust by plate movements. Such a situation occurs today in Japan, which probably resembles the New England of the late Palaeozoic era. At Kingsgate, metamorphosed sediments of probable Permian age have been intruded by late Permian/early Triassic granite. Mineralisation is confined to 70 or more roughly cylindrical ore bodies within the granite, at a short distance from its intrusive contact.

Molybdenum mineralisation in New England is mostly located in a NE/SW trending zone including the deposits at Wunglebung, Deepwater, Glen Eden, Kingsgate and Booralong. At each place the mineralisation is near an intrusive granite margin, sometimes in pipe formations (as at Kingsgate and Deepwater) and sometimes associated with aplite and pegmatite bodies within the granite (as at Booralong). Similar relationships have been observed in North Queensland deposits. It would appear that volatile components of the magma, containing quartz, sulfur, bismuth and molybdenum in solution, have crystallised within the mostly solidified granite at a late stage of the cooling of the intrusion.

The most prominent of the igneous rocks at Kingsgate is a coarse, mottled grey adamellite, rich in quartz and orthoclase, nonporphyritic and with no apparent structure. It differs noticeably from the tin bearing granites seen, for example, at Torrington. The common dark minerals within the granite are biotite and hornblende. However, this rock does not appear to be the actual host rock for the deposits, which is more likely to a very acid granite usually not seen in outcrop but generally reduced to a thick gravelly soil. Several other granitic bodies also outcrop in the area. The former sedimentary rocks intruded by the granite may be seen in road cuttings below the mines and along the Yarrow River. They are essentially altered siltstone of presumed Permian age. No fossils are known from these rocks at Kingsgate, but Permian marine fossils have been found in similar rocks further south.

There has been considerable speculation as to the reasons why the Kingsgate mineralisation occurs in the way it does. The best that can be said is that the pipes are separate intrusions into the main plutonic mass, whose location has been controlled by the pressure and temperature conditions prevailing at the time. The pipes are very irregular in shape and structure and frequently change direction, dip and diameter as they are followed downwards. Some are characterised by branches, others by their variation in diameter from a few centimetres to many metres across. In some the minerals completely fill the pipe, in others there are open spaces lined with huge quartz crystals. All are of the same essential character, being composed in part of granite in which the felspar has been altered to sericite, in part of quartz and in part of veins and segregations of ore minerals.

Sach's Pipe (the Old 45) has been studied in some detail. More information on individual pipes is to be found in the next chapter.


Song Studies. Bible studies based on hymns and songs
Shoalhaven District Geology.

Saturday, 9 May 2015

THE RUBY HILL GARNET DEPOSIT NEAR BINGARA, NEW ENGLAND NSW AUSTRALIA

THE RUBY HILL GARNET DEPOSIT NEAR BINGARA, NEW ENGLAND NSW AUSTRALIA
Google Earth photo - the signpost coming from the north
I’ve passed by this place several times without going in. As there are many references to it as a fossicking area, I suppose it must be open to the public, though whether this is public or private land I’m unable to say. It is well signposted, more visibly so when travelling south from Bingara, being on the right hand side of the road linking Bingara to Barraba (commonly called the Fossickers Way). The most precise distance from Bingara I’ve read is 18.6km, though from what point in the town this was measured is not stated. There are no rubies there – they proved to be garnets – but there have been several dubious claims of diamonds being found there. More of this later.
The earliest reference to the place appears to be DA Porter, “Notes on Some Minerals and Mineral Locations in the Northern Districts of NSW”, published in the Journal of the Royal Society of NSW in 1894. I read this many years ago and there is no certainty that Porter is referring to the present day Ruby Hill. The next reference is by JM Curran, in the same Journal in 1896. JF Lovering quotes Curran as saying that a red, pyrope-rich garnet was found in a coarsely-crystallising basic rock within the basalt at Ruby Hill. The easiest reference to read from the early days is in “The Mineral Resources of NSW”, by EF Pittman, 1901. Search Trove.
Photo from Pittman, 1901
Pittman wrote as follows: “A small hill, about eighty feet in height, which is intersected by several basalt dykes, was pegged out some years ago by a miner named Butt, who was attracted by some red crystals in the basalt. Under the impression that these crystals were rubies, Butt drove a tunnel, forty feet in length, in one of the hard basalt dykes, and only desisted on being informed that the red stones were garnets and of no value.” Pittman went on to tell of the search for diamonds on the same hill. He gives the date 1889 for the formation of a diamond prospecting syndicate. The upshot of this was that “Ten diamonds, weighing in the aggregate four and one-eighth carats, were obtained from it. The diamonds were remarkable in that they each had a distinct depression or pitting on one of the faces.”
The first edition of “Gemstones”, Mineral Industry series 18, page 66, (1960) (DIGS reference R00050829) throws doubt on the validity of this discovery; however it also states that “in 1922 ER Dickens treated alluvial material in the vicinity of Ruby Hill, and it is reported that some hundreds of small diamonds were obtained but were not sold”. I wonder what became of them? There are other Ruby Hills in NSW so perhaps these diamonds came from elsewhere. The second edition (1980, DIGS reference R00050830) mentions only the earlier find.

Map from Pittman, 1901
What emerges from these readings is that the garnets were found both in the breccia, which makes up much of the hill, and in the dykes which intrude it. They are apparently derived from fragments of eclogite found in the breccia (along with many other types of rock, which is typical of brecciated volcanic pipes) and in the later basalt, which they could have entered from the breccia when it was intruded by the basaltic magma. They might also have been carried up from a considerable depth from the same source rock as that penetrated by the breccia.
Lovering addressed the nature of the eclogite fragments in an article in the Journal of the Royal Society of NSW in 1964 (Volume 97, pages 73-79). He stated “Eclogites occurring as inclusions in igneous pipes are particularly important in that they may well represent direct samples of the upper mantle caught up in the magma of the pipe during its passage to the earth’s surface”. He prefers to call the inclusions “garnet granulite” and adds that individual xenocrysts of garnet are also found in the breccia and dykes, no doubt derived from the breakdown of the granulite.

Because of the (apparently) superficial resemblance of the occurrence to South African diamond bearing kimberlite pipes, there has been quite a lot of interest in this locality as a potential source of diamonds.  One such report, written by GL Rolfe for Anaconda Australia Inc. in 1979 (DIGS reference R00015604), concluded that the rocks there were unlikely to be diamantiferous. Commenting on the garnets, the report states “The most common xenocryst in both the breccia and basalt is garnet. The garnets are generally orange pink in colour, size varies from 1 to 5mm. Reaction of the garnet with the magma during ascent to the surface has resulted in kelyphitic rims one to two mm wide. The keliphytic rims consist of clay mineral and zeolites. The rims are wider in the basalt than the breccia, indicating a longer period of disequilibrium between the garnet and magma”.

Reports from fossickers of outings to Ruby Hill are few. Some say they found little or nothing, others that there were numerous small garnets in the soil. Obviously, the soil derived from the dykes is going to be the most productive, so these places need to be identified from the map, rather than by digging at random. It seems that nearly all the gems will be found in a small sized mesh sieve, a coarser sieve being used to remove larger pieces of rock etc. There will probably be no water on site, so dry sieving to concentrate the gems followed by a dip in water you will need to take with you is the most likely approach. There may be water in nearby Hall’s Creek, but this will almost certainly be on private property.

Another useful reference:  A thread from Prospecting Australia’s website (here). There are some interesting photographs in this thread, but as there is no mention of sapphire being found at Ruby Hill in any other reference, the bluish stones may have come from somewhere else. Some object for scale (such as a coin) in the photos would have helped.




Sunday, 25 August 2013

PRETTY VALLEY QUARTZ

PRETTY VALLEY QUARTZ



Quartz crystals turn up in the wash at Pretty Valley all the time. Many of them are hardly waterworn; the occasional piece is. The majority of the schorl tourmaline and topaz is hardly worn either, and together these represent a suite of minerals which has a different origin from the sapphire, zircon and black spinel.

We can speculate all we like about the origin of the second group of minerals, which have no doubt come from a basalt source somewhere not far distant. The origin of the first group is probably the Kingsgate-like pipes which occur on the hill to the north-west. It is possible that the topaz and tourmaline have another source as they are not typically found with quartz at Kingsgate.

The reference from which the map is derived is titled “Crystal Report No.14 Kingsgate Crystal Field (Part 1)”. The DIGS reference is GS1943/013. It is part of a group of reports relating to the search for quality quartz crystals during World War II. If there is a Part 2, I haven’t found it yet.

From the map it would be reasonable to assume that there are other, undiscovered quartz pipes upstream from the fossicking location since the pipes shown are over the hill in the drainage area of a tributary of Bladey Grass Creek. This stream comes in on the western side some distance downstream from the fossicking location and it is likely that it too will be carrying quartz crystals. It’s not likely that the sapphire group of gemstones will be found in that creek, but you never know until it has been checked out.

As has been reported in an earlier Blog entry, there is a little gold in Bladey Grass Creek and several times I have been told of pieces of a green gemmy mineral, probably tourmaline, being found there. If anyone turns up something unusual there, let us know by way of a comment here. I need to remind readers that this is private property and that trespassers (poachers or thieves) are certainly not welcome. 

You can experience gem hunting around Glen Innes through my You Tube site until you pay the area a visit. Click here . Several videos deal with Pretty Valley. For related Blog entries on Pretty Valley, use the search box at the top of the page.



 
Zircon, topaz and quartz from Pretty Valley