StreetNames

Something that I have idly been pondering for a few weeks now has to do with the renaming of streets. Durban, the most populous city in KwaZulu-Natal has renamed a lot of them in the last decade or so. Since I mentioned it obliquely on Twitter (1, 2) earlier, I thought I would write it up here. Durban has probably gone further than most large South African cities with regards to renaming roads and streets. (Certainly I have heard more about it there, but that might be proximity). Many of these are uncontroversial, where a road described what it did and now commemorates someone. * “Ruth First Highway” is a better name than “Northern Freeway”. * Old Fort Road ran in front of the Old Fort and is now KE Masinga Road. Others have changed who was commemorated, which can raise hackles: * Jan Smuts Highway was renamed to King Cetswayo Highway. * Stanley Copley Drive is now RD Naidu Drive Still others have links to other places, usually the places the people who built the area are from: * Blair Atholl Road is now Rodger Sishi Road * Kensingston Drive has become Adelaide Tambo Drive (The full list is available on […]

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AfricaArray Field School – Day 19 – Final Presentations and Celebrations

To finish off the field school, everyone gave a presentation. The geophysics groups gave one on a particular scientific question, while the geochem people talked about what they had been up to. These were generally pretty cool, especially the geochem. This was mostly because I had no real idea what they had been up to, and it was good to hear. They have done some fairly original (preliminary) studies which sound well worthwhile, and certainly add something to the knowledge of the Molopo Farms Complex (which seems to be related to the Bushveld Complex). For the rest, because I was involved in gathering at least some of the data, there were no big surprises. The magnetic data was pretty interesting though, and might lead to some revision being required for the geological map of the area, which is always nice to know. After the presentations, we headed over to the geosciences building and had a late lunch/farewell celebration. We all got certificates of attendance, which was nice. They did get “Bentley” wrong though, which makes me wonder if “Bently” a common name? We also got some t-shirts, sponsored by MeerCat and Red Dog: After that, we headed to Musa’s (Dr […]

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AfricaArray Field School – Day 18 – MeerCAT Ladies and (even more) processing

This morning we had a very interesting talk from two consulting geophysicists, who formed a company named MeerCAT. (I can not find a website for some reason, but will try and add it if I come across it. The closest I have is a (LinkedIn profile)[https://za.linkedin.com/pub/lindsay-linzer-nee-andersen/6/b60/b79].) Something slightly unusual about this consulting company is that both the people running it (and who make up the whole staff, in fact) are women: Lindsay Linzer and Jeanne Trickett. The talk mostly focused on how they had arrived where they had, through the CSIR and other institutions before striking out on their own. There was also some discussion on what geophysicists can expect if they work as part of a multi-disciplinary team. The question and answer session was really good. There was some good advice regarding how consultants in South Africa are working, as well as talk about what gaps exist. Notably, (and this came up a couple times during the field school as well) the various engineering fields could really benefit from knowing more about what geophysics can offer them. Some of this comes from the mining industry (sinking shafts, seismic information on rock mechanics). This would mostly be for civil and […]

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AfricaArray Field School – Day 16-17 – GPR, UNESCO and processing

Day 16 – GPR, or mowing the pavement. This morning was an interesting overview of the uses and limitations of ground-penetrating radar (GPR), which looks like a really useful tool. This was given by (Red Dog Scientific Services)[http://reddoggeo.com/]. I can think of a couple times it would have been useful for the geotech work I was doing at Ground Africa. What I found interesting was that you can very effectively use the same processing methods as one uses for seismic data, despite the nature of the waves being very different (seismic vs electromagnetic). The ability to detect buried objects fairly easily is immensely valuable though. After the presentation, we went back to our old haunt on the library lawns to test it. Unfortunately, they were watering the lawns, and had been quite enthusiastic about doing so, which meant that we had limited areas to play with. (The lawns were water-logged, and GPR struggles to see through water.) In any case, we took turns to use it on the paved path (which looked a bit strange, given that the machine looks like a lawnmower), and got some cool results for pretty minimal effort: We could see the engineered fill under the […]

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AfricaArray Field School – Day 14-15 – Game viewing and back to reality

Day 14 – Pilanesberg Today was an opportunity for the tourists to see somewhere new, including some animals, with a visit to the Pilanesberg Game Reserve. Since I have done a fair amount of game-viewing, I decided to give it a miss. Instead I met some old friends, and had a generally lovely day (including some gorgeous winter weather: clear blue sky, warm in the sun, slightly chilly wind). Apparently there was an elephant sighting, along with some rhino and giraffe. Overall, I think I made a good call to relax with old friends instead. Day 15 Today we started work again. This is mostly further processing and interpreting of the field data. We also had a really interesting talk about the geology and formation of the Vredefort Dome by Roger, the head of school here at Wits. He has spent pretty much all of his career working on it, so it was really nice to get some of this information from the horse’s mouth, so to say. The scale involved is actually pretty scary: a 300km wide crater forming in less than 10 minutes. Geologists do not usually even think about things on such a timescale; a million years […]

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AfricaArray Field School – The Field pt 2

Part two of the field component of the field school. Again, this is a collection of pre-written posts. AfricaArray Field School – Day 10 We had a bit of a rest day today, in order to collect samples to determine their physical properties. For some reason, each group needed ten samples of each lithology, of which there are five (according to Sue: granite, quartzite, dolerite, basalt and a granophyre). I saw some of the other groups, who had a couple of other types instead. Notably, what at least one group was calling dolerite, we are calling basalt (because you can see the flow structures, so it is probably not intrusive…). In order to measure density, we have to get an average weight in air and water of each sample, so each group has about 500 readings to make. Which is going to occupy the evenings, between regular processing. Other stuff that happened today was some basic stuff related to the vehicles: how to hitch a trailer, how to change a tyre, that sort of thing. I believe that there was some amusement about this, given what people previously knew about cars. Anyway, at least one tyre was changed, and hopefully […]

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AfricaArray Field School – The Field pt1

So connectivity for me was particularly poor out in the Dome, but I did write what happened, so here is the day-by-day, as I typed it up in the field. This is a long entry, so I will probably break it up into two. I will not put any photos in, because most of the time I had my head down, but the photos that I took are up on Facebook as usual. AfricaArray Field School – Day 6 Today we finally headed off into the field proper. This entailed checking out of our rooms in Barnato Hall (and the ladies out of David Webster) and proceeding to hurry up and wait for a while. Mostly this was because of the sheer amount of equipment that we will be needing. We managed to fill up three bakkies and their trailers, but most of us had a really comfortable ride, only half-filling a 60-seater bus. The bus was picking up the third year geology students, actually from the same place as we were going, which was quite convenient, all told. The farm is pretty good, with plenty of showers, and lots of room. Despite the room, the list said to bring […]

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AfricaArray Field School – Day 5 – Requests for bids

This morning we started off with a discussion about the work happening here are Wits (and across the continent) regarding broadband seismology. This is really the “Array” part of the AfricaArray Field School. There are 50-odd permanent seismic stations across sub-Saharan Africa, which are used to investigate the structure of the earth. These things are pretty impressive: able to detect nanometre movements over a couple of minutes. This needs some serious processing, which is something that Wits is developing/has developed the capacity for, at their new Seismic Research Centre. Some of these seismometers are going to be placed on temporary deployment, for between 18 and 24 months, somewhere on the western limb of the Bushveld Complex. We then used the rest of the day to complete our request for bids, before giving a short presentation about how we would do each, and what it would cost. Sue and Ray asked us questions, about various aspects of the design of the survey and so on. I quite enjoyed this, although I was surprised at the variation in cost from group to group. I suspect some people will be losing money on these. The group I was with won, which means we […]

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AfricaArray Field School – Day 4

I got a bit caught up in other things last night, so this is a day late. In any case, on with it! The day started with “Safety” Sue’s lecture about, well, safety. Most of the stuff is common sense, and a lot of it is relevant to how industry tends to do things. Things like seatbelts, not using cellphones while driving, being aware of ticks, watching for heatstroke, not licking the electrodes of the resistivity system while it is operating, that sort of thing. OK, she did not actually say the last point, but I am pretty sure it is still good advice. We also went over some of the admin for the field school, in terms of water and food arrangements. This was followed by a lecture about the rocks of the Witwatersrand Basin by one of the students here at Wits, TJ. He kept to a fairly high-level overview, in order to highlight the different rocks that can be found, as well as some information on the mineralisation in the basin, the most notable of which is obviously gold. He also brought along some rocks from it for us to have a look at. Following this, we […]

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AfricaArray Field School – Day 3

Today started with a short lecture about the petrology and geochemistry of the Bushveld Complex. I was a bit out of my depth, since the last time I used a petrographic microscope in anger was in about 2010. Luckily the bit of prac tutoring that I did last year helped me at least remember what plagioclase and pyroxenite looked like. There are some seriously cool rocks in the BC, and it is absolutely massive. One million cubic kilometres of mafic magma, between seven and nine kilometres thick. And the age dates suggest that it emplaced and cooled within a million years or so. I mean, that is a lot of magma, in a very short space of time. This made me wonder why it never made to surface, like other large igneous provinces, such as the Deccan and Siberian Traps. Answers on a postcard (or a journal article cover), please. As a side-note, the Wits Petrology Lab is seriously cool. I think it only opened last year, and it looks like a great place to teach and learn petrology: great microscopes, an easy way for the lecturer to show specific examples of thin sections. I was slightly jealous, I will […]

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