10 February, 2011

A crater remains

Sometimes there are things that would be easy not to notice.  And it's so difficult to get a photo that shows what actually there is.  But here Doggie is standing on the edge of a crater, or depression in the ground that is over 600mm deep and about 6 meters in diameter.  We have two of them.  An neighbour tells me that explosives were used to take soundings leaving this crater and others.  Listening and analysing the echos is like taking a radar view of the ground layers beneath.
Overgrown crater.  With the ever present Doggie.
The theory has been that the river used to flow beneath here.  Nowadays there is perhaps 50 to 100  meters of gravel over the original bed, forming the flat field we know.   Find that original riverbed and you will find the same amounts of gold found that were found in the present riverbed.  Maybe 20 million dollars under our 5 hectare field.  There has been a constant interest for 150 years now.
It's had to tell how long ago this crater was formed.
When the Bell Kilgour mine was floated as a commercial enterprise in the early 1930s this field formed part of our New Zealand's most expensive land purchase ever.  They paid massive amounts for an area of land of about one hundred acres - (old measurement.)  (that's forty hectares of which we now own two)

See the post that relates to that.
Seismic exploration would have been part of that development.

Another time seismic explosive survey might have formed the crater was in the 1980s.   I have yet to investigate the history of two shafts sunk about 200 meters on either side of this crater.  These were steel lined efforts about 50 meters deep and had all the benefits of expensive modern machinery.  Both must have failed to find the original riverbed obviously as there was no further work.

But I also have another story of a shaft in 1942 which produced quite a lot of gold.  Although it was only a four man operation.  Not sure where that was.  Maybe within a few hundred meters. 

Seismic testing must have been quite a fuss.  The crater today is a quiet mystery lying amongst the peaceful long grass.

This final photo shows a government sponsored seismic test just north of here at Bendigo in 1934, which was part of a series, maybe including our own crater.
Bendigo.  1934.  How to disturb lots of rabbits.


  1. Dear Kerry

    This is a bit of a coincidence: I helped with seismic work in Central Otago in the late '80s.

    Not looking for gold, but to establish the structure or profile if you like, of faults detected in gravity surveys.

    To get the shock waves into the ground it's best if the explosives are buried deeply. However our most exciting ones were detonated underwater as each cubic metre of water weighs about a ton, and on these ones the idea was to produce small earthquake, while measuring stations were set up at a few sites in Central Otago, and even Dunedin. However none were detected that far away.

    The information gathered I believe passed to the Clyde Dam builders/owners, and established benchmarks which can be referenced should there be a large earthquake event.

    The scientists I worked with were of the opinion the Kawarau river once flowed elsewhere and as you mentioned, if it's gorge could be found, thus too, much gold might be found also.

    The dam project employed quite a famous geologist and if I recall his name was Royden Thomson, and if you could contact him I'm sure he'd be, as always, a treasure trove of information. It's quite possible he lives in Cromwell.



  2. Sounds like a fun job that. What fun. I should add you to my list of rabbit botherers.
    Royden Thomson sounds familiar. But do we really want to find that former gorge? What would that do to my plantings?

  3. I was thinking that he'd probably know the history of your craters. I've never met him, but I understand he's got a great grasp of the history of the area.



  4. Near where I come from in Tipperary we had a very industrial coal mining in the late 18C and early 19C. Today you will still see fields pocked like your one.
    Here every so often a farmer will lose a cow to one of these things after the shoring of a shaft or tunnel collapses and the entire infill vanishes like sugar from a bag.
    Did you see this

  5. Vince: Yes Bell Kilgour is right here and the report reinforces the history as I know it. It would seem the operation was created to mine gullible investors as much as gold. Nothing new under the sun is there.

  6. On the other hand, the city of Johannesburg was built ON the goldmines, which are filling with water now the mines are abandoned, and are just months from overflowing. The acid runoff is already causing hippos to go blind. Glad for you, your gold mines are interesting history, rather than active.

    Thanks for following my blog. My father was from New Zealand.

  7. What a fascinating landscape. For some reason it makes me think of the work of Bernard Lassus, who equates depth in a landscape with the passage time. He did an extraordinary plan for Villette in Paris (sadly unrealized) that was a public park somehow contained in something akin to a well. I hesitate to recommend such an approach! - but it may be worth looking at some of his designs. Good luck with your garden - and thanks for your kind words and comments on my blog.

  8. Thanks landscapelover. Your comment about landscape "in a well" rings through. One of the concepts we clearly labeled in the house design process was "we are in the bottom of a bowl and all the views are up." and we used that in simple but significant ways. eg the tops of the windows are set high - because you do need to look upwards.
    You will get that impression clearly by looking at the Post " Mountain Ranges".

  9. Anonymous15 July, 2011


    If your property is in the proximity of the Bell-Kilgour claim near Scotland Point, then you are on the site of my grandfather Bill Murray's 145ft Aotearoa Shaft & Mine that was on the property in 1940. In the 1980s, another steel lined shaft was put down by Jeff Connelly (prior to the filling of Lake Dunstan). I have plenty of photo's and plans, and glad to provide copies. Please feel free to get in contact (

    Regards Scott


I would love to hear from you on any of these posts. This blog is not daily news and I will respond to comments even on backdated posts.