Sunday, December 30, 2007

Xmas day trip

My friend Ian and myself left Wanaka mid afternoon on Xmas day for a bit of an expedition though some remoter parts of Central Otago. In the Nevis valley we encountered heavy rain compromising the 24 fords we had to cross, so we pushed on for longer than we'd intended before making our merry tea, to reach the summit at 1100 meters, that leads to a steep descent into Southland.

We had 30 mins. of sun to set up the truck off the road before it started snowing:

Next morning at 8 am we found ourselves dealing with a couple of inches of new snow:

We sledged the truck back onto the road without the need for chains, Ian mt. biked down and we were off for a coffee at our favourite tea rooms in Athol. We descended back into summer, and it looked pretty odd in the heavy Xmas traffic to have much white stuff melting and flying off the vehicle.

We headed to Queenstown then up to Skippers [Ian again riding] for a cuppa, then back out again in the evening when there is less traffic [it's a single lane road with legendary drop-offs, but is really sweet to drive if there is no on-coming traffic]. Last time I was in there at night with Dougal I had to shift a dead goat that had fallen on the road just before we got there. It was very Monty Python and also very smelly: that pungent goat oder, and I'd forgotten about it, before assisting it on it's descent.

The restored Skippers school house:

We ended up in the Arrow river for our last night, and while I'm talking of Monty Python, when we woke up in the morning there was a ute parked in the river:

Ian rang the number on the door thinking it may have been stolen and abandoned, but no, it was the owner's son who'd got it stuck.

And so ended 3 memorable days!

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Friday, December 28, 2007

What is a stamper battery?

Shirley commented on my last post asking what a stamper battery is. I must admit to getting a bit carried away here, but the question prompted some thought and I have a project coming up that has to have an explanation written, so here is the first draft:

A stamper battery [a row of rock crushing stampers] represents one of many techniques to separate gold from earth and rock. The ratio of gold to dirt/rock is what determines the financial viability of a gold mining operation. Machinery is inevitably employed and has a capital cost as well as a very high maintenance cost: water is usually involved too and steel machinery is not best lubricated by water especially as it has rock particles in suspension in a gold mining operation [I'll leave it to the reader's imagination to ponder the downstream effects on water and river quality!].

There are many areas or land in my homeland of Central Otago where what is called the peneplain is exposed by weathering, maybe aided by glaciers having stripped away substantial debris earlier, and also faulting crinkling the surface of the earth thus exposing edges where weathering can occur faster. Anyway you don't have to rush off to the link below - just to know that rocks in keeping with a high percentage of gold are on the surface or can be mined/transported easily to a battery.

These rocks will typically be much heavier than our greywacke and shists, and they've once been part of layers of sediment cooked with pressure under extreme weight and silica has been forced all about. Quartz is also evident, along with "petrified wood".

Stampers have to be constructed out of material tougher than silica impregnated rocks and crush same, then water is used to transport the crushings through a complicated refining process that leads to a water, gold and rock crushings mix [slurry].

Water was often also brought to the battery to power it, via races constructed with great effort out of creeks and around hill sides slowly loosing height to the site of the battery. The levels were calculated by using old gin bottles almost full of water [hence the phrase "spirit levels" perhaps].

When at the battery the water flowed onto a wheel thus suppling motion to a shaft on which a number of cams [all offset to ensure balance] would lift and then drop [stamp] very heavy cylinders of steel onto the rocks. The noise is awesome [some enthusiasts have restored one on the West Coast and I've been fortunate to see it running briefly]

This photo shows the curved cams that raise and drop the shafts that have the huge weights at the bottom:

The last photo below shows the wheels on the left that turn the shaft. At the level of Camille's waist you can see the weights [stampers], and the photo is taken looking towards the exit side of the battery - in other words where it's taken from would have had quite sophisticated sluices with water washing the crushings along them, first over steel with large holes/gratings so rocks could be stopped while the fines dropped through, eventually to be caught on carpet in more chutes [water still used], and eventually separated out by the use of mercury and heat, and made into ingots

For me two factors in these operations astound me: how did they get the components on-site? And how did they live [or not live] in the winters!? Keep in mind that it is springtime when water is most abundant - this must surely mean working hard and long hours to have the material ready. Especially in some situations where, the water being temporarily frozen would aid the mining!

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Tuesday, December 25, 2007

Merry Xmas


Christmas holiday stage one is complete - we've been fishing at Poolburn [no luck there despite Dougal getting three nibbles]. We had a friend of John and Julie's with us too - another photographer, Camille from France, so we got a lot of nice shots to make up for the lack of fish.

We got pounded by westerly winds after a night up high, so adjourned east, then north for lunch in Naesby, then a visit to the Blue Lakes, before coming home to Wanaka via Thompson's Gorge.

On the way home we found an old stamper battery I knew of, had been restored...

So.. have a good day, and don't over eat. I'm now off to the Skippers for a couple of days with an old friend
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Sunday, December 16, 2007

Wanaka's changing landscape


It's common now to see a crane on the skyline in Wanaka - up until a few days ago there were two of them, but today when I went out to record same one had gone. The above one is working on the new back packers building just sth. east of the super market.

There was 5 minutes of stunning sunset in the week past, and I happened to be down by the lake so I got playful with that one.

Today was Dougal's birthday. Fifteen wonderful years! We had strawberries and ice cream for afternoon tea.

New offices? behind the old THC hotel complex - Wanaka Art Center on the right...

This shot from Mt Iron shows Wanaka Puzzling World at the bottom adding colour to this shot of the sewage ponds - note the new development just the right and slightly behind same...

Dougal was in Chch last week on school camp and bought some clothes...

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Saturday, December 8, 2007

More pictures from the mini holiday in Otago

Just been socialising this weekend [work related barbeque] after a hard week's work. Here are a few more pictures taken on my last follies:

Shirley asked about Moas up creeks so here we have what the sign post in my last post pointed to 31Kms away - what I believe is the old Moa Creek hotel...

Dawn at Poolburn...

Rocks used as posts...

Coffee stops in Ranfurly - someone else with wheels joined the throngs of Rail Trail bikers...

Disused farm building near Patearoa...

Lastly on Sat. I downloaded the Mac blog editing application MarsEdit. With the trial version it quickly became evident that this is the tool for me - not only in terms of the speed with which I can do this blog, but how it can speed up posting to multiple. I did however have a technical hitch uploading pictures, but an email to support had it nailed. The service was impressive [thanks Daniel in Boston]

It looks like our stunning weather is coming to an end today - I'm going to miss the searing dry heat, but the coolness should make life easier.

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Sunday, December 2, 2007

A mini holiday in Otago

More pictures than words this week, which was a mini holiday: a couple of days in the hills over Lake Hawea way, and then a multi day trip to Dunedin over the Old Dunstan Road.

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