One of the impressive open pits at Mogolokwena Platinum Mine. Picture taken by Jackie Gauntlett.
Today’s Monday Geology Picture and description are courtesy of my husband Jackie Gauntlett, who is sharing another picture from his recent field trip as part of his masters degree in Exploration Geology at Rhodes University.
From Jackie:
Mogolokwena Platinum Mine is the largest platinum mine in the world and is situated on the Northern Limb of the Bushveld Complex in South Africa. This image shows one of four open pits currently being mined by Anglo Platinum on this mine. South Africa holds around 90% of the world’s platinum reserves, and it is envisioned that the Mogolokwena pits could one day extend almost 100 km in uninterrupted length. At the moment, Mogolokwena Mine has a life of mine of 130 years, a number that climbs by decades after every drilling program. At this rate the exploration team had better stop working so quickly as they’re likely to drill themselves out of a job! This mine truly represents a world class platinum deposit.
Figure 1. Pillow lavas. Picture taken by Jackie Gauntlett.
The Barberton Mountainland in north-eastern South Africa is underlain by the some of the oldest and best preserved rocks in the world – the Barberton Greenstone Belt. The rocks of this unique area allow geologists to peer into the world of 3.5 billion years ago. The variety of rocks making up this ancient belt provide some of the earliest evidence for deep bodies of water (pillow lavas – Figure 1), running water and fluvial systems (conglomerate beds and cross-bedding (Figures 2 and 3)), tidal systems (symmetrical ripples, Figure 4) and…our ancestors. The oldest form of life was discovered here, a bacterial micro fossil Archaeospheroides barbertonis and has been identified as being 3.2 billion years old (Figure 5).
Figure 2. Conglomerate. Picture taken by Jackie Gauntlett.Figure 3. Cross-bedding. Picture taken by Jackie Gauntlett.Figure 4. Ripple marks. Picture taken by Jackie Gauntlett.Figure 5. Archean fossils! Picture taken by Jackie Gauntlett.
The Barberton Makhonjwa Geotrail is an amazing initiative, and I urge anyone passing through to spend a day absorbing this unique and spectacular part of South Africa. Check out a description of the trail here.
So, I have been quite negligent recently and missed both last week’s and this week’s Monday Geology Picture. My apologies for that! Life has been very busy with things such as writing a paper and preparing for upcoming fieldwork. To make up for missing the Monday Geology Picture the last two weeks, my husband Jackie is going to share two sets of pictures (one today, one tomorrow) from his recent mining / exploration geology field trip in South Africa.
Without further ado, here’s the first guest post from my husband Jackie Gauntlett:
Chromitite seams in the Bushveld Igneous Complex, exposed at Dwars Rivier. Picture taken by Jackie Gauntlett.Informational sign for the Dwars River Heritage Site in the Bushveld Igneous Complex. Picture taken by Jackie Gauntlett.
The Bushveld Igneous Complex in northern South Africa is an amazing, yet somewhat enigmatic, geological phenomenon. At around 8 km thick, this layered igneous intrusion is the largest in the world by an order of magnitude. Its features also allow geologists a look into the inner workings of large magma chambers. In the image above we see layers of chromitite (a rock made up of ~40% chromite) within an anorthosite package. Conventional thinking from other similar igneous bodies would suggest that these layers were laid down inside a magma chamber one on top of the other during fractional crystallisation. However, outcrops like the one at Dwarsrivier show bifurcating seams which often rejoin and anorthosite xenoliths (rip-up clasts maybe?), alluding to a horizontal intrusion mechanism within a hot chamber. Interestingly, even though bifurcating seams are common, the total chromitite thickness remains constant and individual seams can be traced – across 200 km!
First of all, I want to apologize to my readers that blogging here on Georneys has been somewhat light over the past several weeks. There are a couple of reasons why.
The first reason is that my work as a geologist for a marine gold exploration company has been very busy. Work has been going very well, but as a new industry geologist I’ve been working hard to learn as much as possible and keep up with the work load. However, I’m really enjoying my job and feel extremely grateful to have found a good place for me to do what I love– geology.
The second reason is that a few weeks ago I was home alone in Cape Town, South Africa when robbers brazenly broke into the flat. I was not physically harmed, but I lost my laptop and was quite shaken by the experience. So, I’ve been resting and recovering. I had trouble sleeping for awhile, but I am slowly but surely returning to normal. My husband and I are in the process of installing some additional security– an unfortunate necessity here in South Africa. We’ve also bought extra hard drives and have signed up for on-line back-up (hard drive back-ups don’t help when the thieves steal hard drives, too!). I had a full computer back-up (carefully hidden away!) that was a couple of months old, but I did lose some vacation and geology pictures and a few other things. Everyone, please remember to back up your computers often! It’s heartbreaking to lose things when your laptop is stolen or when it crashes.
Second of all, I want to give you a preview of something to come here on Georneys: pictures and some guest posts by my husband Jackie, who is currently pursuing his masters degree in Exploration Geology at Rhodes University in Grahamstown, South Africa. Jackie is working on his degree part-time over 2-3 years. There are two field trips associated with the degree, and Jackie is currently on the first field trip. He’s been visiting some amazing geological places throughout South Africa and has been taking plenty of pictures.
Below are a few pictures from Jackie’s field trip. Captions are courtesy of Jackie. These pictures are just from a BlackBerry phone– when my husband returns in a week or so, he’ll download the pictures from the proper camera. I can’t wait to see those!
The Bushveld Complex: UG1 chromitite seams in anorthosite. A geological wonder!Mgolokwena open-pit platinum mine.Molokwane North open pit (at Mgolokwena).
Old mining picture in the Gold Reef City museum. Looks like hard work!
This week I’m sharing the last pictures from my September 2012 visit to Gold Reef City, Gold Reef City, a gold mining themed amusement park in Johannesburg, South Africa. The amusement park is built on the site of an old gold mine, and these pictures provide some insight into what life was like on the mine in days gone by. There is a museum with some pictures and information on what life was like for the miners– it wasn’t always great, by any means. There are also some historical buildings that were used by the mine supervisors and their families. These buildings are filled with historical artifacts. The museum and historical houses weren’t particularly crowded– I guess the rides are much more attractive than the history, which is a shame.
Another picture in the museum.A recreation of some of the mineworkers' quarters. Doesn't look very comfortable!My husband Jackie in front of one of the old houses that belonged to the mine managers / bosses.A sign in front of one of the historical houses.Another sign in front of another historical house.Inside one of the houses.Another view of the room. This bed looks much more comfortable than where the mineworkers slept!A dining room table. I really like Willow Ware plates such as the ones on the table.An old classroom.
I hope you’ve enjoyed all the pictures from Gold Reef City. If you ever find yourself in Johannesburg, I definitely recommend a visit to the park.
I have a few more pictures to share with you from my September 2012 visit to Gold Reef City, a gold mining themed amusement park in Johannesburg, South Africa. Check out some of my previous “Monday Geology Picture” posts for some more pictures from the park.
This week I’m sharing some pictures of trains. One of the things that I like about Gold Reef City is that there are trains (or train-like things? I’m not sure all of these pictures show true trains) throughout the park. The trains fit well with the park’s mining theme– I imagine that there were many trains among the mines of Johannesburg in the past. If anyone is a train buff and knows anything about these trains, please feel free to leave a comment below.
Another view of the little orange train.I think this maybe isn't a train? Anyone know what it is?A train... and a peacock! There are peacocks wandering throughout the park. They're lovely. Also, that's a rollercoaster in the background.My husband Jackie posing next to one of the trains.Another little train? Or train-like thing?Another train with peacocks.
I still have a few more pictures to share from Gold Reef City. Over the next couple of weeks, I want to share some pictures from the historical exhibits that will give some insight into what life was like for mine bosses and their workers during early Johannesburg mining days. Life wasn’t too great for many of the workers, but you’ll learn more about that next week. It’s a fascinating history.
The first ride that we went on was some sort of crazy rollercoaster where they lift you up and then drop you very fast. It’s one of the scariest rides in the park, apparently. I wasn’t too impressed with my husband as I thought we were just going on a normal rollercoaster. After I recovered from the scary ride, we did go on a couple of the easier rollercoasters and also a couple of fun water rides.There are all sorts of fun amusement park rides, and many of them have gold mining themes. There is also a wonderful Ferris Wheel. From the top, you can see large mine tailings that remind you of Johannesburg’s extensive gold mining history.
The scary ride that drops you suddenly. They have made this ride look like an old mine shaft.Thunder Mountain! Hang on... isn't that also at Disney?On the Thunder Mountain log ride at Gold Reef City.A steep part of the log ride.Another water ride. I like this one. You go down rapids in a giant spinning boat.One of the rollercoasters!A view of the Ferris Wheel.Some main tailings (in the distance) viewed from the top of the Ferris Wheel.More mine tailings (distance) viewed from the top of the Ferris Wheel.Downtown Johannesburg viewed from the top of the Ferris Wheel.
After passing through the mining-themed entrance, going on an underground mine tour, and watching a gold pouring demonstration at Gold Reef City (a gold mining themed amusement park in Johannesburg, South Africa), my husband and I decided to try the “Gold Panning” activity. I must admit, we were somewhat disappointed in this activity, which involved “panning” for some shiny metal (but not gold– it was very different in texture, density, etc.) in a fake stream filled with some quartz sand. My husband and I both work for a gold exploration company, so we have experience panning for real gold in the field. We found the Gold Reef City “Gold Panning” experience to be less-than-satisfying. But we took a picture of me “panning” anyway.
Stay tuned… there will be more pictures from Gold Reef City next week!
Here are some pictures of real gold panning in Alaska:
My husband Jackie panning for gold on the beach in Nome, Alaska, Summer 2012.Me, posing with a bag of heavy mineral concentrate (and gold!) on the Nome beach. That's an old gold mining dredge in the background. Nome, Alaska, Summer 2012.A gold pan with garnet-rich sand and little flakes of gold. Nome, Alaska, Summer 2012.
Gold pouring demonstration? Sounds highly interesting! Those "This demonstration is not performed with real gold" signs were everywhere. I guess it would be very tempting to steal the gold otherwise!
After entering through the impressive entrance and going on the underground mine tour, my husband and I went to the gold pouring demonstration at Gold Reef City, a theme park in Johannesburg, South Africa that is situated on the site of an old gold mine. We visited the theme park back in September 2012.
The gold pouring demonstration doesn’t use real gold but is nevertheless impressive! Also, there is a real gold brick (I think– possibly it’s a fake brick) displayed on a table at the end of the demonstration. My husband tells me that in the old days they used to say that whoever could pick up the gold brick with just two fingers could take it home with them. I don’t think anyone was ever successful!
The gold price in September 2012. This sign is updated daily, I believe. The gold price has dropped significantly since last September.Another reminder.Demonstration #1.Demonstration #2.Demonstration #3.Demonstration #4.Hot hot hot!Hot and glowing.A real gold brick. I think. Possibly this is a fake brick.
That’s all for now. I’ll share some more pictures from Gold Reef City next week.
My husband Jackie and I during the underground mine tour.
For a few weeks, I’m sharing some pictures from a visit to Gold Reef City, a gold mining themed amusement park in Johannesburg, South Africa, back in September 2012. Last week I shared some pictures of the mining-themed entrance. This week I am sharing some pictures from the underground mine tour. The park is located on the site of an old gold mine. Now that water is no longer being pumped out of the mine in large quantities, most of the mine has flooded. However, the upper part of the mine is still accessible, and you can arrange to go on an underground tour with a guide. I highly recommend the tour. It’s fascinating to see the mine, and the guide that we had was extremely knowledgeable. My husband and I were the only people signed up for the early morning tour, so our guide spent extra time with us and even pointed out a few things that weren’t on the regular tour. Since my husband and I are in the gold mining industry ourselves, we certainly had plenty of questions. Our guide said that she appreciated our enthusiasm and said that, sadly, many of the schoolchildren who go on the tour are not very interested– they are much more interested in the rides and entertainment up top!
Without further ado, here are several pictures from the underground mine tour:
Early extent of the mine, 1916-1920. Mine goes to 975 meters depth.The mine just before its closure in 1977. Mine goes to 3,200 meters depth. The elevator down the mineshaft.We were quite excited to be headed down the mineshaft.Mining equipment. The walls are painted white to increase the effect of illumination.This box was used to store dynamite. It has a sloping top to prevent miners from accidentally putting lanterns on top of it. Another dynamite box.There is an underground pub behind this door. You can rent it out for functions. Fun!Old mining posters.
I blogged about the above mining posters previously.
Mining supports and a chute.Jackie checking out one of the old chutes.A simple device for counting.A collapsed part of the mining shaft.A rock drill.Rocks!Mining shaft with creepy mannequin man.Mine shaft supports.Closer view of the mine shaft surfaceInformational sign about the mine. We went to the red depth-- the mine used to go quite a bit deeper!Another view of the rockfaceOld informational sign.Another chute. That's travertine (carbonate rock) forming on the bottom.Another old informational mine sign. I have not idea what a "Tchisa Stick" is. Does anyone know?More signs.Even more signs.Headed back to the elevator.
Hope you enjoyed these pictures. Next week I’ll share some more pictures from Gold Reef City– from the gold brick pouring demonstration!
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