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Sunday, 28 September 2014

THE OTTERY MINE, TENT HILL NEAR EMMAVILLE NSW AUSTRALIA



The site in December 1967
The Ottery Mine is one of the few places in NSW where the public can go and get a good idea of what went on at a mine in “the good old days”. Usually, such sites are out of bounds, being on current mining leases or private land or considered too dangerous to allow people in. The Ottery is different – a lot of money has been spent to make the old mine site accessible and provide good information so you can see for yourself how it all came together.
The mine is close to the Tent Hill-Torrington road just a few km from the old tin mining town of Emmaville, itself about 40km from Glen Innes. For more information on how to get there and what there is to see, I recommend the following websites: Aussietowns – Emmaville (here), the Northern NSW site (here) and Aussie Sapphire’s Blog (here).
The site in May 1991
Before I move on to more technical stuff, here are few personal observations which might
enhance your


visit. I first saw this place in December 1967. The main features haven’t changed greatly since then – the chimney, the condensing chambers, the damaged environment (though this has been improved a lot by the mine site rehabilitation that has gone on since then.) In 1988 I collected specimens of pyrite and arsenopyrite there. You can still smell the sulphurous odour around the site. I observed (on the right near the car park) that there were a number of decaying wooden barrels which still contained a whitish substance. Maybe they are still there and perhaps it is refined arsenic oxide (as I first thought). More likely it is cement, which was delivered in barrels before the double paper bags of more recent years.
May 1991
On several occasions since then, I have been underground in the old workings (a potentially very dangerous thing to do), though most openings were blocked off even then. It was a real eye opener to catch a glimpse of the conditions in which the old time miners worked and to see the mineral veins in their natural condition in places in the rock walls.
As you will soon discover when you start reading about the Ottery, there were two main stages in the history of the mine. The tin stage began during the mining boom at Vegetable Creek (now called Emmaville) which commenced in 1872. Prospectors scoured the district, one of whom (Alexander Ottery) discovered the outcrop of the cassiterite-bearing veins sometime between 1875 and 1881. The mine was opened up in 1882 and the Glen Smelting Works was established to extract metallic tin. The site of the smelters is at the junction of the Emmaville-Deepwater and Torrington roads (Tent Hill).
From The Mineral Industry of NSW (EF Pittman 1901)
Eventually mining tin became unprofitable and the site passed into the hands of the firm William Cooper and Nephews (Australia), who then mined the arsenopyrite ore bodies to produce arsenic oxide which was widely used in the manufacture of sheep dip (1920’s on). This is the time when the surviving condensation chambers and chimney were constructed. There has been a lot of investigation of the site in more recent times and on several occasions when passing by on the way to Torrington I’ve observed drilling in progress on the hill. No doubt the price of tin is the key to any future mining there.
From The Tin-Mining Industry in NSW (JE Carne1911)
You could never call the geology of a site like this “simple”, but basically there are at least 5 quartz veins associated with fissures in a body of granite which intrudes claystone and tuff. This granite is probably related to the Mole granite to the north around Torrington. Arsenopyrite (FeAsS) and cassiterite (SnO₂) were the main ore minerals extracted, but pyrrhotite (Fes) and pyrite (FeS₂) are also present. As is common with such ore bodies, many other minerals have been identified in the ore, but are unlikely to be found as hand specimens.
To gain a better understanding of this place, and to see how it fitted in to the wider mining field, there are many good references you can download. Here are just a few.
A compendium of documents assembled by the Geological Survey of NSW may be found in DIGS (reference number R00045777). Doing a search in DIGS using the location “Tent Hill” and keyword “Ottery” will turn up much more. Of particular interest in the compendium is a document written by Harry Julius, whose father was the mine manager in the arsenic mining days.
The Minerama book title Cassiterite (1984) may be downloaded from here. See the part dealing with Emmaville in particular.
The Tin-Mining Industry in NSW 1911 by JE Carne (DIGS reference R00050677) was written near the end of the tin mining stage and has a good section on the Ottery Mine.
My You Tube gemstone playlist may be found here. I have three other playlists - the Blue Mountains, Glen Innes and New Zealand.
The Ottery Mine in 1922. From Grafton/Maclean mine data information

2 comments:

  1. Very Interesting John,

    I actually have many original photo's from the Ottery & Tent Hill area, and am a descendant of the Mine Manager you mention above.

    ReplyDelete
  2. The Emmaville Mining Museum would be glad to receive copies of any photos. Thanks for your comment.

    ReplyDelete