Wild Dog Adventure Riding

General => About South Africa... => Topic started by: LeonDude on January 27, 2013, 05:28:22 pm

Title: Caving anybody? Check this out!
Post by: LeonDude on January 27, 2013, 05:28:22 pm
Itís been a while since Iíve had time to do any kind of report, but on 19 January we re - visited a sinkhole that is so amazing that I just have to tell you about it.
This sinkhole formed about 15 years ago to the south of Joburg, and only one person had ever been lowered down it. Back then, the farmer awoke one night from a thundering sound like an explosion. Upon investigating the next morning, they found that the corn field had a gaping hole in it. Things were a bit more relaxed back then, regarding safety measures, and they tied the farmerís son into a harness and lowered him down the hole. The son saw nothing at the bottom, and he was pulled out again, all wide eyed and scared.
So fifteen years go past and after visiting the hole one day the caving club decide they have to go down there. What they find is nothing short of amazing. I didnít go down, but Cave Girl did, and these are her photographs.
There is a cave. It seems that when the sinkhole had first fallen in the cave had been plugged up, but now it has opened up and the team went in. They discovered a new cave, and followed it for 400 meters. That is a huge amount of cave. After 400 meters they came to a very steep and long drop which they could not pass.
Next month, they will be going back with more equipment to map and explore the cave, so maybe then Iíll bring you some more info.
For now, here are a few pics.

Here is the first glimpse of the hole. It doesnít look like much, and is about 18 meters across.
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/19JanCaving/DSCF4136_zps2a7f37cc.jpg)

Uh, how deep did you say this hole was? At first we didnít know, as the electronic equipment wouldnít give us a reading.
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/19JanCaving/DSCF4148_zps276f455e.jpg)

Can you see the caver on the end of the rope? Poor Gerrie. He was the first one to go down, and it turned out the rope was too short. So Gerrie had to climb back up the rope. Now look, you do a climb like that only once a day, so Gerrie will have to wait until we go back to have his chance to explore the cave.  In this photo he is still six meters from the bottom of the cave.
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/19JanCaving/DSCF4149_zps16fe6162.jpg)

This is the rig they used. They parked a vehicle on each side of the hole and then John, an ex merchant mariner, strung a rig across for the cavers to descend and ascend from.
You guys can have it, Iím not hanging 50 meters above the ground. Yep, the hole is fifty meters deep, measured by the length of rope it took to reach the bottom of the sinkhole.
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/19JanCaving/DSCF4168_zps4b5b572f.jpg)

This picture is taken from inside the cave, looking out into the sinkhole. The floor of the cave heads down at about 35 degrees.
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/19JanCaving/DSCF4185_zps63b23a63.jpg)

Over the years a lot of stuff had made its way down there, mostly wire and old tyres.
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/19JanCaving/DSCF4196_zps832d718b.jpg)

I find the next two photos the most amazing, as it shows the bottom up view of the sinkhole, with a caver on-rope. They use the SRT method of getting out of there, meaning you climb out by yourself, on your own steam.
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/19JanCaving/DSCF4226_zpsc5a4112e.jpg)


(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/19JanCaving/DSCF4222_zps3fdd301e.jpg)

I wish I could convince myself to hang in the air 50 meters above ground, then I could go down there and give you a personal account, but my palms go clammy just thinking about it.
Next month, Iíll try to find time to update this for you! .


Title: Re: Caving anybody? Check this out!
Post by: Fuzzy Muzzy on January 27, 2013, 05:33:18 pm
Pretty freaking cool

i would love to go down but am not convinced I could pull myself back up.  :imaposer:
Title: Re: Caving anybody? Check this out!
Post by: laurika on January 27, 2013, 10:11:21 pm
Cave girl, u are one brave bokkie! I am amazed by you! Nice pics!
Title: Re: Caving anybody? Check this out!
Post by: Wildcoast on January 28, 2013, 07:18:13 am
The dude standing on the edge is also very brave  :o
Title: Re: Caving anybody? Check this out!
Post by: Cave Girl on January 28, 2013, 11:34:00 am
Safety in these situations are priorety so the guy on the edge was in a harness linked to a safety line  :) so was not going anywhere unexpected  :thumleft:
Title: Re: Caving anybody? Check this out!
Post by: Gat Slag on January 28, 2013, 11:44:11 am
Cool, cannot wait for the next set of pics...  :sip:
Title: Re: Caving anybody? Check this out!
Post by: Kerritz on January 28, 2013, 11:44:49 am

I wish I could convince myself to hang in the air 50 meters above ground, then I could go down there and give you a personal account, but my palms go clammy just thinking about it.


Hmmmmm....interresant...maar ek share jou sentiments Leon...twee kanse wat ek daar in donner.....Cave Girl het baie meer moed as ek.
Title: Re: Caving anybody? Check this out!
Post by: Hagar on January 29, 2013, 06:53:45 am
Please posts some pictures of the cave.  Strange that the farmer did not fence it off.  Cattle/drunks/bikes/ tractors may fall into it.
Title: Re: Caving anybody? Check this out!
Post by: Ratt on January 29, 2013, 07:33:09 am
Sweet! Wa is die gat? Sal wat gee om da te in
Title: Re: Caving anybody? Check this out!
Post by: LeonDude on January 29, 2013, 07:43:32 am
Please posts some pictures of the cave.  Strange that the farmer did not fence it off.  Cattle/drunks/bikes/ tractors may fall into it.
It used to be fenced off, but the fence is now mostly a lot of rusted barbed wire lying around. There is still a berm around the hole, so you have to ride over the berm before you can fall into the hole. But yeah, pretty scary.
Title: Re: Caving anybody? Check this out!
Post by: subie on January 29, 2013, 07:48:19 am
Ja! Gooi nog. Baie interresant :thumleft:
Title: Re: Caving anybody? Check this out!
Post by: LeonDude on January 29, 2013, 07:54:40 am
Sweet! Wa is die gat? Sal wat gee om da te in
Ratt, if you want to try this sort of thing, I seriously suggest you contact CG and join the caving club. It's cheap, and they will give you all the training you need, plus you will get to see other caves too.
This is not a beginners cave however, (at least according to me!). So you might have to get a bit of experience before they let you go down.

As for more photies, these are the best ones I've got. Next month they are going back, hope to get you more photos then.
Title: Re: Caving anybody? Check this out!
Post by: arrowfeather on January 29, 2013, 07:55:53 am
very nice!
Title: Re: Caving anybody? Check this out!
Post by: Ratt on January 29, 2013, 10:02:52 am
Sweet! Wa is die gat? Sal wat gee om da te in
Ratt, if you want to try this sort of thing, I seriously suggest you contact CG and join the caving club. It's cheap, and they will give you all the training you need, plus you will get to see other caves too.
This is not a beginners cave however, (at least according to me!). So you might have to get a bit of experience before they let you go down.

As for more photies, these are the best ones I've got. Next month they are going back, hope to get you more photos then.


The club is up there in GP if Im not mistaken, Im in knysna, so its gonna be extremely expensive for me to join and be there for events/meets/training days. I would if I could though  :thumleft:
Title: Re: Caving anybody? Check this out!
Post by: LeonDude on January 29, 2013, 10:12:37 am
There are caving clubs all over SA, so if you can get experience down there with a club, I'm sure you could arrange with CG to get the guys to take you out to this cave.  :thumleft:
The big thing is to get the experience, this cave is not for beginners.
Title: Re: Caving anybody? Check this out!
Post by: Heimer on January 29, 2013, 10:39:03 am
SUb. EK wil nog sien  :thumleft:
Title: Re: Caving anybody? Check this out!
Post by: W1P30UT on January 29, 2013, 12:30:04 pm
Thats it!!!

I'm coming with next time :)
Title: Re: Caving anybody? Check this out!
Post by: White Rhino on January 29, 2013, 12:33:56 pm
Sub(merged) :laughing4:
Title: Re: Caving anybody? Check this out!
Post by: Kelevra on January 29, 2013, 12:58:04 pm
Pretty freaking cool

i would love to go down but am not convinced I could pull myself back up.  :imaposer:

Easy, loosen rope from one bakkie, start the opposite bakkie, engage first, drop clutch and bob's your uncle.
Title: Re: Caving anybody? Check this out!
Post by: Pietcoke on January 29, 2013, 01:21:25 pm
 :sip:
Title: Re: Caving anybody? Check this out!
Post by: Cave Girl on January 29, 2013, 01:35:57 pm
Actually we have done a "deep pit" rescue at another cave 86m deep  - a little more complicated than untying ropes  :) but yes with a few pulleys and extra rope, more than doable  :) But all the fun is in the cardio workout  :thumleft:
Title: Re: Caving anybody? Check this out!
Post by: LeonDude on February 19, 2013, 03:41:40 pm
As promised, the cavers have been back at the big sinkhole, and once again it was a big day for all.

Iím just going to hijack my own report for a moment here. Seeing as I do not do caves, I walked up the hill behind the cave, and at the top found the most amazing ruins. As far as I know, they are from Shaka Zulu, whoís people drove out everything and anything that lived here. If there are historians aboard, please feel free to give your opinion. (Or correct me if Iím wrong)
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/100_3875_zps48a4f1cc.jpg)

(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/100_3882_zps43448422.jpg)

(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/100_3888_zps3c6b71e4.jpg)

(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/100_3892_zps48c3dc35.jpg)


Ok so back to the caving, this time there were seven cavers that went down, and one experienced caver and myself that would stay outside and wait for them. The caving pics are yet again all from Cave Girl.
Remember Gerry, who last time climbed down only to find that the rope was too short? Well this time he made sure he got down, here he is!
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190071_zps5f98738d.jpg)

Last time some people asked me what the square object in the cave was, and I didnít know. Well we now know itís a danger sign, which somebody obviously tossed into the cave. (Outside the sinkhole there is no obvious sign of danger other than some very old, rusted and almost non Ė existent barbed wire, and a very low earth berm).
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190150_zps0671ebdd.jpg)

The cave mouth leading off from the sinkhole. Note the yellow tape hanging on the side to the left of the picture. That is my measuring tape, and itís 50 meters long. Didnít quite make it to the bottom.
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190153_zpsd71411f1.jpg)

A bit of bat guano
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190176_zps00aa0472.jpg)

This is one of the few formations, itís a little pipe that is forming off the roof of the cave.
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190177_zps822af33c.jpg)

Looking back at the cave entrance
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190188_zpsa29fda21.jpg)

The next two is a black substance, identified as Manganese by our tame geologist Pedro.
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190210_zpscf2492d1.jpg)

(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190206_zps72fa7927.jpg)

The next five pictures are what CG describes as fluffy white stuff growing on the rocks. Some kind of crystal.
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190230_zpsbeb254a9.jpg)

(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190229_zps327cba7b.jpg)

(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190248_zps720bdd0c.jpg)

(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190250_zps322d5253.jpg)

(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190263_zpsc5e777d7.jpg)

Then there are these very exquisite small white crystals.

(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190273_zpsd2788ff3.jpg)

(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190280_zpsee46ccb0.jpg)

(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190275_zpsd4eb07bb.jpg)

This shows one of the walls of the cave.
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190347_zpsa4e28e22.jpg)

Now Iím in a bit of trouble, because I was told the names of the next two formations, but forgot them. Come on DB9 or Roxens, help me out!
I do know the first one was made when the rock was shattered by the Fredeford meteorite event, and the cracks were filled immediatly with molten stone.
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190352_zps140bfe3f.jpg)

Iím not sure about this one, but itís so neat it almost looks man-made.
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190361_zps4693c4cf.jpg)

This is the hole that stopped the cavers on their first expedition down. This time they rigged a ladder across.
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190380_zpsce411fbc.jpg)

This is Irene, having a rest. Yes, a lot of woman do caving.
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190381_zpsff5bd728.jpg)

And lastly, but most importantly, a photo of our own Cave Girl, trying to see into the middle of the earth.
(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190382_zps0a76a847.jpg)

By six oíclock that night the experienced caver waiting outside with me was well worried, and promised that if the group was not out by eight, he was going to call in a rescue team. As CG had told me they would not be out before well past nightfall I felt there was no reason for worry, and sure enough the group came out at just past seven.
This time we had rigged a pulley system to get the cavers out, so I could not take any pictures because I was hauling on a rope, sorry.
Anyways, it turns out they had gone 530 meters into the cave, and then they hit a sheer wall. There was another hole leading off from the wall, but it was too high for them to reach, so they will have to go back with a bolting kit.
For those of you who donít know, a cave of 530 meters long is big, very, very big.


Title: Re: Caving anybody? Check this out!
Post by: Oupa Foe-rie on February 19, 2013, 03:58:31 pm
Very interesting and thanks for sharing ................  :thumleft:
Title: Re: Caving anybody? Check this out!
Post by: Brandt on February 19, 2013, 04:01:23 pm
Very interesting and thanks for sharing ................  :thumleft:
+1000 It feels if we discover the new cave with you guys. Very interesting...
Title: Re: Caving anybody? Check this out!
Post by: Kerritz on February 19, 2013, 05:37:50 pm
Very interesting and thanks for sharing ................  :thumleft:
+1000 It feels if we discover the new cave with you guys. Very interesting...

I concur.....maar ek ry eerder weer BMW voor ek in daai gat afklim........net 'n grappie ok...'n fricken grappie.  :biggrin:
Title: Re: Caving anybody? Check this out!
Post by: Cave Girl on February 19, 2013, 06:46:17 pm
Some info from me  :)

Main chamber including the actual sink hole - 50m x 150m at widest points - total lenght of cave surveyed - 700m - highest point taken by me in main passage 25m deepest point 235.7m

I didn't actually go near "Bat passage 1" but Gerrie did and said there were aprox 500-600 bats in the passage, flew around for a bit and disappeared into the passage.

Main chamber has a few alcoves and 3 passages - 1 surveyed 530m and goes but at ~15m above ground so we will need to go back with a bolting kit. one passage we were unable to get more than 3-4m into due to a massive 30m drop right at the start (Bat passage 1) . and 1 passage goes up quite steeply for ~ 6m and ends.
Not many bats flying round in the main chamber - or if they were they were high up and we didn't see them. One small low chamber 8m x 5m has evidence of a small group of bats - fresh guano (Photo)... and no bats in there.
Main passage itself had 3 "sink holes" along it - the passage carried on but 15m in the air so we could not get into it with the equipment we had. The whole way along the passage you could hear bats in the roof so my guess is there are a few thousand bats in the cave.
We only got out after dark - so missed any "emergence" if there was one - Leon was on top but was so busy with hauling us out the cave did not have time to pay much attention to the sky around him - but did notice quite a few bats coming up through the sink hole -  I was lying on the floor looking up while the guys were being hauled up, and there were not "masses" of bats as I had expected there would be, but there seemed to be constant activity for at least 30min.
We had a few bats come check out what we were doing lying around at the bottom - visual and my experience says they were horseshoe where as the "masses" were by virtue of the noise in the cave, long fingered.

My very uneducated guess is there is a 2nd entrance to the cave - somewhere along the passage we could not get into because based on the noise inside the cave there just didn't seem to be enough bat activity in the sink hole - mind you we were pretty distracted. Will defiantly like to be able to watch the entrance at sunset to get a better feel for the number of bats in the cave.

Photo correction : White fluffy stuff is calcite - arogonite crystals (SP) and as Pedro explained formed after the hole was opened - me on the ladder - was taking a rest as I had just climbed up a 8m rope ladder and it seemed like a good place to take a breather - and look into the 4/5m hole I was climbing over  >:D
Title: Re: Caving anybody? Check this out!
Post by: Mikie on February 19, 2013, 06:49:46 pm
How awesome Caves have always fascinated me.
I would love to go down there.
As long as there are no tight spots I think I would be fine.
I remember in the Cango caves there is the devils chimney, going up there really did freak me out a bit, the tight places,,,,
Title: Re: Caving anybody? Check this out!
Post by: Mikie on February 19, 2013, 06:51:53 pm
I am actually surprised you didnt find any Skeletons down there, perfect umping ground for bodies if you ask me  :)
Title: Re: Caving anybody? Check this out!
Post by: LeonDude on February 19, 2013, 07:31:02 pm
Thanks Cave Girl.
Once John has drawn the cave, maybe we can put a picture of the survey on here?
Title: Re: Caving anybody? Check this out!
Post by: Inprogress on February 19, 2013, 08:24:54 pm
Awesome! My first though when I saw the picture from below upwards....movie set  ;D
Title: Re: Caving anybody? Check this out!
Post by: Toors on February 20, 2013, 02:17:33 pm
any water for the cave divers among us??
Title: Re: Caving anybody? Check this out!
Post by: LeonDude on February 20, 2013, 03:18:38 pm
Not so far, and I don't expect them to find any either because of the amount of mining activity in the area.
Title: Re: Caving anybody? Check this out!
Post by: Toors on February 20, 2013, 03:24:04 pm
Not so far, and I don't expect them to find any either because of the amount of mining activity in the area.


aah well, could only hope  ;)
Title: Re: Caving anybody? Check this out!
Post by: SlŠinte Mhaith on February 20, 2013, 03:33:57 pm
Fascinating
Title: Re: Caving anybody? Check this out!
Post by: Rodlau on February 24, 2013, 07:00:37 pm
Great photos and very interesting.  But caving not for me.  I really admire all the cavers.  Looking forward to more
Title: Re: Caving anybody? Check this out!
Post by: White Rhino on February 25, 2013, 12:43:37 pm
Awesome, yet freaky ... down in the bowels of mother earth .... is this a new find?
Title: Re: Caving anybody? Check this out!
Post by: LeonDude on February 25, 2013, 04:50:59 pm
Awesome, yet freaky ... down in the bowels of mother earth .... is this a new find?
Yes, brand new!
Title: Re: Caving anybody? Check this out!
Post by: LeonDude on February 26, 2013, 04:01:20 pm
Ah, I think I got this one

(http://i272.photobucket.com/albums/jj190/leondekock/tours/2013/Caving%2016%20Feb%202013/PB190352_zps140bfe3f.jpg)

It is called Pseudotachylite. Pseudo because you usually find this stuff in volcanoes, and this was found at a meteor impact site.
I still have conflicting reports on where the black stuff that fills the cracks come from, according to The Story of Earth and Life, it is the rock itself that got melted and flowed into the cracks.
According to my tame Professor it was some other rock or something that melted and got injected there.
Title: Re: Caving anybody? Check this out!
Post by: DeepBass9 on February 26, 2013, 05:16:31 pm
The fluffy spiky crystals are aragonite which is a form of calcite. : http://en.wikipedia.org/wiki/Aragonite

The pic above looks like a fine dusting of aragonite on weathered dolomite. The red is likely an iron oxide, and the darker minerals will be manganese oxide in all likelyhood.

These are dissolution cavities where the slightly acidic ground water in contact with the atmosphere, dissolves the soluble dolomite. The water ends up saturated with dissolved minerals and these can re precipitate out again to form the crystals.
Title: Re: Caving anybody? Check this out!
Post by: roxenz on February 27, 2013, 03:40:28 pm
Ah, I think I got this one

It is called Pseudotachylite.

It is quite possible that the dark lines on the photograph are pseudotachylite, and yes, in and around the Vredefort Dome area there are many occurences of this rock type.  It is a severely tectonised rock, similar to melting the rock, but not at high temperatures,  basically the rock was liquified due to extreme dynamic shock (high pressure as opposed to high temperature).  Obvious cause was the Vredefort impact, which was a rather spectacular event. Concentric "ripples" in the surrounding earth can be observed on satellite images more than 1000km away from the impact area.  Let's just say that if you were anywhere on the current land area of South Africa you probably would not have survived the fire works...

I cannot make out what the white rock is, probably dolomite or quartzite - both are brittle and would crack that way.

There are similar veins of pseudotachylite visible in the quartzites of most of the gold mines along the west Witwatersrand.  It is generally speculated that they are related to the Vredefort event as well.
Title: Re: Caving anybody? Check this out!
Post by: roxenz on February 27, 2013, 03:58:27 pm
Not so far, and I don't expect them to find any either because of the amount of mining activity in the area.


The mines have to dewater the general area in which they operate, to prevent the mines from flooding.  Most of the surrounding water is stored in the dolomites.  The mines on the West Rand have to pump this water from one compartment to another, because Rand Water Board needs the water for greater Jozi.  A "compartment" is a block of porous dolomite that is "sealed off" by relatively impervious dolerite dykes.  When a snot-nosed geo I had to map these things so that the mines and Rand Water could settle who was stealing whose water...

As the rocks surrounding the mines are dewatered, the water level goes down and these caves (which were filled with water) become dry.  Without the water pressure to help support the caves, they start to collapse.  Sometimes the collapsing area forms a chimney that continues to collapse until it reaches the surface - bingo! sinkhole.

That hilly area near Westonaria (near the old "North Shaft" of Western Areas Gold Mine) has a few sinkholes in it, where the softer Karoo sediments have aided the collapsing roof of caves.  There was one that the mine tried to fill with waste rock, but IIRC they gave up.  In the Waterpan Village of the mine, a small sinkhole opened up in a street and swallowed part of a house (no one hurt or killed).

There is also a very large fault running north-south which cuts a small tar road in that area.  It displaces the road vertically by a few centimetres.  What makes this noteworthy is that this fault has been mapped with seismic surveys and it cuts through both the Karoo rocks and Wits rocks, but with diferent amounts of displacement.  Basically what that means is that this fault was already there when the Karoo rocks were deposited some 300 million years ago, and it is still active.  The Earth is a many splendoured thing...
Title: Re: Caving anybody? Check this out!
Post by: LeonDude on February 27, 2013, 04:09:32 pm
Cool, thanks!  :thumleft:
Title: Re: Caving anybody? Check this out!
Post by: Cave Girl on March 06, 2013, 05:48:30 am
So we going back this weekend to try finish off the cave survey if anyone is keen to join let me know. Climbing and rope work experience is necessary!  :)
Title: Re: Caving anybody? Check this out!
Post by: White Rhino on March 06, 2013, 06:01:13 am
Not so far, and I don't expect them to find any either because of the amount of mining activity in the area.


The mines have to dewater the general area in which they operate, to prevent the mines from flooding.  Most of the surrounding water is stored in the dolomites.  The mines on the West Rand have to pump this water from one compartment to another, because Rand Water Board needs the water for greater Jozi.  A "compartment" is a block of porous dolomite that is "sealed off" by relatively impervious dolerite dykes.  When a snot-nosed geo I had to map these things so that the mines and Rand Water could settle who was stealing whose water...

As the rocks surrounding the mines are dewatered, the water level goes down and these caves (which were filled with water) become dry.  Without the water pressure to help support the caves, they start to collapse.  Sometimes the collapsing area forms a chimney that continues to collapse until it reaches the surface - bingo! sinkhole.

That hilly area near Westonaria (near the old "North Shaft" of Western Areas Gold Mine) has a few sinkholes in it, where the softer Karoo sediments have aided the collapsing roof of caves.  There was one that the mine tried to fill with waste rock, but IIRC they gave up.  In the Waterpan Village of the mine, a small sinkhole opened up in a street and swallowed part of a house (no one hurt or killed).

There is also a very large fault running north-south which cuts a small tar road in that area.  It displaces the road vertically by a few centimetres.  What makes this noteworthy is that this fault has been mapped with seismic surveys and it cuts through both the Karoo rocks and Wits rocks, but with diferent amounts of displacement.  Basically what that means is that this fault was already there when the Karoo rocks were deposited some 300 million years ago, and it is still active.  The Earth is a many splendoured thing...
Interesting .... are you suggesting that the "cave" connects to a mine shaft?
Title: Re: Caving anybody? Check this out!
Post by: Cave Girl on March 06, 2013, 09:47:31 am
Probably not  :( but there were 2 passages we could not get into without extra equipment

Title: Re: Caving anybody? Check this out!
Post by: H2O on March 06, 2013, 10:53:50 am
Itís been a while since Iíve had time to do any kind of report, but on 19 January we re - visited a sinkhole that is so amazing that I just have to tell you about it.
This sinkhole formed about 15 years ago to the south of Joburg, and only one person had ever been lowered down it. Back then, the farmer awoke one night from a thundering sound like an explosion. Upon investigating the next morning, they found that the corn field had a gaping hole in it.

As dit JOU land was, sou jy nog die balls gehad het om hier trekker te ry?  Klink of die boer net die stuk toegespan het & nog rustig rondom die gat boer!
Title: Re: Caving anybody? Check this out!
Post by: LeonDude on March 06, 2013, 12:12:44 pm
H2O, that is part of the reason why he allows us on his land, he would like to know what's going on down there.
Title: Re: Caving anybody? Check this out!
Post by: Renier on March 06, 2013, 12:59:48 pm
very cool! looking forward to the rest!
Title: Re: Caving anybody? Check this out!
Post by: Cave Girl on March 11, 2013, 04:49:30 pm
Just a quick update. We went back and spent the weekend at the cave - I didn't go down on Saturday as we needed a caver above ground and none else was around - I also wanted to try capture some photo's of the bats - alas the bats came out to late for my camera to get any real pic's - managed to capture one of the bats and confirmed it was a  Natal bent wing / Schreibers' long-fingered bat,  (Miniopterus schreibersii)
The guys pushed "bat passage" which took most the day - then headed back to the main passage to bolt the wall - having to carry quite a bit of equipment it was slow going. They only got out the cave after 7pm with LD doing a super human task of hauling the first person out almost single handed although I like to think I helped a bit. Sitting round the camp fire in the evening we were updated on the events - Gerrie found 2 really stunning formations and didn't have a camera so no photo's  :( he then had to leave early on Sunday so could not take us back to the "spot" to take photo's and I didn't find them on Sunday  :'(
We were also informed that the cave is actually on mine land and not private land. Officially it is SA's deepest dry cave recorded - so a really great find!
Sunday I went down but spent most the day rechecking the survey as there were a few ? that needed corrections. Came up early. The rest of the guys went through to the back and managed to put in 5 bolts - still about 3 or 4 short to reach the passage - so lots more work  :)
I am sure LD will post about his Geology lesson he was able to get out of Pedro  :thumleft:
Title: Re: Caving anybody? Check this out!
Post by: LeonDude on March 12, 2013, 05:55:28 pm
Actually, this weekend was more work than play for the cavers. One team was busy mapping the cave while another team was bolting the wall that leads up to the passage that they still havenít been able to get to. According to the team doing the bolting itís slow going because the wall is very soft.
As for the geology lesson, Iím not sure what I can tell you without boring the pants of most people, so Iíll just tell you about a new type of rock Iíve learned this weekend called Fubarolite. That is rock that has been Fucked Up Beyond All Recognition Ė olite. It is amazing what the Vredeford event did to some of the rocks in that area.
We did investigate some of the other holes and in one of the holes we could clearly see two cave entrances leading off. While we were there a small owl noticed us and promptly flew into one of the caves. I will let you guys know if we ever get a chance to explore that cave.
Some piccies to follow.
Title: Re: Caving anybody? Check this out!
Post by: LeonDude on March 12, 2013, 06:07:02 pm
Ok, here is the pics. The first 3 shows the hole with the caves I mentioned. These are brand new caves, never explored before.
This hole is not as deep as the one we are busy at, it's only about 20 meters deep. Ok, that is still lots of scary.
The last photo is of a crack that has opened up in a field. The goelogist agreed that this is probably going to become a sinkhole in the near future. I hope I'm not anywhere near when it does. But walking around there, you know that there are scary holes just waiting to open up beneath you. Just so you know how deep that crack is - Gerrie is more than 2 meters tall, he is a giant.
You tread carefully.  :biggrin:
Title: Re: Caving anybody? Check this out!
Post by: Cave Girl on March 14, 2013, 05:30:26 pm
They are going back on Saturday to go check out the other sink holes and possible caves and I can't go  :'(
Title: Re: Caving anybody? Check this out!
Post by: cloudgazer on March 14, 2013, 05:42:47 pm
wow - interesting thread.
Title: Re: Caving anybody? Check this out!
Post by: EssBee on April 02, 2013, 10:40:24 am
Very interesting! Thanks all!  :biggrin:
Title: Re: Caving anybody? Check this out!
Post by: krazy-eyes on April 02, 2013, 12:13:06 pm
They are going back on Saturday to go check out the other sink holes and possible caves and I can't go  :'(

yus! i want to go!
Title: Re: Caving anybody? Check this out!
Post by: Cave Girl on April 02, 2013, 02:32:03 pm
The caving club is offering a SRT training day on April 13th with a trip to the cave on the 14th April - Cost for no-non caving club members is R70.00 and includes a meal - if you are interested payment needs to be made by Monday next week (15th) - PM me for bank details etc if you interested.
Sharron
Title: Re: Caving anybody? Check this out!
Post by: THROTTLE JOCKEY on April 17, 2014, 03:08:03 pm
 :sip:
Title: Re: Caving anybody? Check this out!
Post by: plonker on December 01, 2014, 05:25:56 pm
Hi CG have there been any more developments at his sink hole/cave of recent times.
Title: Re: Caving anybody? Check this out!
Post by: OomD on December 01, 2014, 06:00:46 pm
Found this thread now, wow impressive. Yeah, any updates? And, isn't caving also called spelunking?
Title: Re: Caving anybody? Check this out!
Post by: LeonDude on December 01, 2014, 06:51:51 pm
Yes, Caving is called spelunking, and yes, the cave has been explored further, but I will leave it to Cave Girl to give us an update.
Title: Re: Caving anybody? Check this out!
Post by: OomD on December 01, 2014, 08:06:49 pm
Yes, Caving is called spelunking, and yes, the cave has been explored further, but I will leave it to Cave Girl to give us an update.

:thumleft:
Title: Re: Caving anybody? Check this out!
Post by: plonker on December 02, 2014, 09:34:32 am
Leon Dude please send her a pm and shake her up a bit as now we are all waiting :thumleft:
Title: Re: Caving anybody? Check this out!
Post by: LeonDude on December 02, 2014, 09:56:02 am
Leon Dude please send her a pm and shake her up a bit as now we are all waiting :thumleft:
Have done, but she is very busy at the moment. I'm sure she'll update ASAP.
Title: Re: Caving anybody? Check this out!
Post by: Cave Girl on December 05, 2014, 09:46:20 pm
There is a trip on the 14th December to survey a passage near the  entrance if anyone is keen.... They have still not found the end of the main passage ....
More info on sec-caving.co.za  :o
Title: Re: Caving anybody? Check this out!
Post by: LeonDude on May 08, 2015, 06:03:53 pm
MAJOR BUMP!
Watch Carte Blanche on Sunday evening to see their scoop on this cave.
Title: Re: Caving anybody? Check this out!
Post by: OomD on May 08, 2015, 09:22:17 pm
MAJOR BUMP!
Watch Carte Blanche on Sunday evening to see their scoop on this cave.

I saw the Carte Blanche inset being advertised, and was wondering if it's the same cave. I'll be watching with interest! So, have they found the end of it yet?
Title: Re: Caving anybody? Check this out!
Post by: roxenz on May 11, 2015, 06:59:18 am
Watched the Carte Blanche program.  The size of those chambers are huge!  Indeed it must have been mind-boggling for the first cavers who went in there.  Must have taken some courage!

The way they presented the geology, it came across that the cave was formed because of (and hence contemporaneous with) the Vredefort meteorite impact, which happened about 2 billion years ago.  Although the rocks and structures they described (cataclasite, etc.) are generally interpreted to be due to the Vredefort event, I cannot imagine that the actual cave is that old.  Looking at the footage of the conditions of the walls (little weathering and little crystal growth) and the blocks of rock lying on the floor only covered by a relatively thin covering of "dirt", I'd say this cave formed relatively recently (which of course can still mean millions of years in geological timescales).  Just thinking what a cave would have had to endure and survive over the last 2 billion years makes the chances of it doing so infinitesimally small.  I suspect that the Carte Blanche presenter might have misunderstood the geologists in the sense that some of the geologic reasons why the cave developed (at a much later stage) was imbedded in the rocks by the much older Vredefort smash-up.

Regardless of the origin, it seems a fairly unique phenomenon, so congrats to Cave Girl and her cohorts for finding & exploring it!
Title: Re: Caving anybody? Check this out!
Post by: Master Beerkie on May 11, 2015, 07:29:49 am
Small HJ  ;D
but the fact that Cave Girl found a lost Leon, is also a fairly unique phenomenon  :peepwall:
Title: Re: Caving anybody? Check this out!
Post by: LeonDude on May 11, 2015, 07:46:29 am
Small HJ  ;D
but the fact that Cave Girl found a lost Leon, is also a fairly unique phenomenon  :peepwall:

But I am a bit younger.  :biggrin:
Title: Re: Caving anybody? Check this out!
Post by: Tom van Brits on May 11, 2015, 08:11:46 am
Very interesting, but clostefobia will get the better of me down there. I'll take to the sky any day but to crawl and walk in confined spaces....no can do
Title: Re: Caving anybody? Check this out!
Post by: BFG on May 11, 2015, 09:36:54 am
Was interesting to watch the Carte Blanche bit last night.
Must be awesome exploring down there.