Showing posts with label geoscience. Show all posts
Showing posts with label geoscience. Show all posts

Wednesday, November 11, 2015

Overview of the Field School 2015

Here is an Amazing summary of this year's field school, a MUST READ:

By: Leslee Salzmann



A ROUND TRIP OF THE COUNTRY

Few people can attest to having circumnavigated South Africa. Whilst this opportunity is usually restricted to mad-hatter-adventurists biking their way around the country and decrepit retirees with a caravan and a few years of free time to kill, this year’s field school saw a bunch of Council for Geoscience interns doing just that! (Okay we missed out Limpopo and the Free State if you must know).

Field mapping school is a Council initiative intended at metamorphosing young and inexperienced additions to the company into gung-ho, GI Joe geologists. It affords new interns the opportunity to witness first-hand the country’s main stratigraphic units (Supergroups) and geography, but more importantly, to gain practical experience in mapping and field work. To this end we spent a week driving to various points of geological fascination, received tuition in imperative skillsets such as remote sensing and GIS, spent ten days in the Richtersveld (Northern Cape) learning the hard way how mapping is done, after which we headed home. But not without passing a number of the country’s largest mines (iron and base metals, limestone, dimension stone, ‘granite’, brick clay and pegmatites included) and being harassed by two emus in Upington. Innumerable drool-worthy geological sites were seen along the way and all of us have been left with memories, stories for the grandkids and perhaps the need for a little psychological counselling and a pedicure.


BREAK IT DOWN

To kick off field mapping school thirteen interns and five soon-to-be-tortured supervisors (Taufeeq, Nick, Neo, Tshimane (aka Doc) and Conrad) met up in Pretoria and made our way slowly and steadily in a clockwise manner around the country. We drove through from Gauteng to the Barberton Greentsone Belt and GeoTrail in Mpumalanga, witnessing some of the oldest rocks in the country.




We passed by coal-bearing deltaic deposits of the Ecca Group as we traversed KwaZulu-Natal – which I’ll have you know were the only redeeming quality of the Karoo Supergroup exposures along the entire eastern coastline! Stopping at Hole in the Wall in the Eastern Cape was a guilty indulgence which we could not pass up. Jennifer –a member of our clan– had never before seen the ocean and this was a milestone experience for her, enough so that she had nightmares of the sea that night (Lets call them dreams rather. Vivid dreams). Shin-high dunking was the most we were going to get out of her despite best efforts.



Thereafter we stopped in East London and Knysna, having entered into the disfigured Cape Fold Belt lithologies.  Onwards we drove into the Western Cape passing through the quaint and idyllic dorpies of Oudtshoorn, Montagu and Worcester. Luckily for us it was still light as we traversed through Bain’s Kloof Pass, one of the ‘most picturesque passes in the Cape’, constructed by the labour of convicts in 1853 and home to insane folding nog al!. In good old Cape Town we received a regal Peninsula tour (geologically oriented I swear). The fish and chips from Kalk Bay were nothing more than a necessary pit stop) and thereafter we made our way up to the north-western limits of the Northern Cape (or as we like to say: the back-ass­ end of nowhere), where we were to carry out the bulk of our fieldtrip season doing what we all came for: mapping and perhaps a little dollop of trial and tribulation.




RICHTERSVELD IMMERSION

The field mapping school this year felt like a passage of fire to the majority of those who attended. This is despite the fact that we were never subjected to the harsh realities of camping in the near-desertlike Richtersveld for a fortnight as previous years have been known to do. Instead we found ourselves rather comfortably accommodated in the house of one of a local “Tannie” and immersed in a cultural experience. We stayed amongst the very isolated and quaint Nama settlement of Eksteenfontein, at the very northern reaches of the Northern Cape, and by the end of the trip were venturing forth with all manner of basterdised Afrikaans in an attempt to communicate with our hosts (most likely to request more vetkoek for breakfast).



Our task for the two weeks was to map and collect structural data for a portion of the Port Nolloth Zone within the Pan-African aged Gariep Belt. This elongate, north-south and coast-parallel striking zone was deposited/intruded during the rifting and separation of the Kalahari Craton of southern Africa from the Rio Del Plata Craton of South America beginning around 771±6 Ma. This rifting led to the formation and infilling of the Adamastor Ocean, but was overprinted with a distinct compressive thrusting regime when these cratons later reunited to form Gondwana (~575 to 545 Ma). It is precisely this later tectonic and metamorphic overprint which confounds and stymies any but the most fervent of structural mappers, and certainly challenged and humbled us as interns as we attempted to conquer our designated map sheets. Rather than allowing us an easy ride, our field school leaders decided to challenge us with an area subjected to extension, transpression, thrusting, back-thrusting, distortion due to intrusions, overturning, metamorphic overprinting and the like. We like to think that we rose to the challenge. They humoured us and allowed us to think that.

Surprisingly, the Richtersveld had other hurdles to throw at us apart from unbearable heat. One day was so miserably windy that it saw me catching my precious notebook by the corner of a single page as it flapped madly in the wind at a 90° angle and threatened to fly away faster than ever I could run to catch it. Losing your notebook in the field would be akin to losing your 3-year old toddler at the beach on New Years. Generally frowned upon and, depending on how much work was in that notebook (or how much you wanted to keep said toddler), unforgiveable.


One choice day saw us heading out in 14°C, rainy and (yes, you guessed it) windy conditions. Some of us hoped for a split second that we would be allowed to stay cuddled up in bed with our fluffy socks, but alas this was not the case. Our slave drivers had us out traipsing through the elements, as per every other day, regardless. Thus there dawned on us the harsh realities of a career spent outdoors, and thus we developed a new level of respect for those in our company who do this on a near-continuous basis- oftentimes in conditions worse than this. A case in point is the ‘Namibian team’ who have been known to work without even a permanent nightly camp but rather by moving camp each night and carrying all provisions (including up to 12L of water) on their backs. Work is carried out across deathly-cold winter nights and fiery summer days alike.


Other hitches encountered in the field were snakes, thorns, ticks and perhaps most hazardous of all: squishy succulents. Beware these unassuming specimens: one false step will have you sliding downhill and falling on your butt in the most painful fashion. Another lethal adversary: dolomite which can shred the most hardened of boots and will most certainly leave you with a bum-flap if you are unwise enough to sit down in a moment of weakness. It had me feeling rather unprofessional as I walked around each day with my panties exposed. The dolomite, together with the searing heat of midday, had a way of eating away at one’s boots and I can boast at having used three tubes of superglue on my shoes in order to see them through the entire fieldtrip. Now that’s hardcore!

Some last highlights for the trip were:

1)    Passing through the UNESCO World Heritage Site in the Richtersveld Ai Ais National Park where we saw a field of literally hundreds of cairns, which had been stacked by passers-by since who knows when as well as some SAN etchings reportedly “1000s of years old”!

2)  The incident with the tick which found a household of girls squealing and ended with the tick’s prolonged and agonised death on the hotplate of the stove.

3)   Trying to get a good look at a snake the size of a ruler which had slithered under a bush, which elicited the fearful warning from one of the girls (who shall remain anonymous. We’ve got you covered): “You’re making it angry! You’re going to make it angry!”

4)   Swimming in the Orange River- a stone’s throw away from the Namibian border

5)  The slaughtering of a sheep. Yes we actually entered into an auction for a sheep to braai. What can we say, the Eksteenfontein lifestyle was charming.



Friday, August 7, 2015

A Historical Aspect of Geoscience

A brief history/thinking of Geoscience: Part 1 - By Gaathier Mahed


Recently at a major German Research facility a talk relating to the micro-, meso- and macro- scales of research in Earth Science was delivered. It was interesting to note how we, as geoscientists, are integrating multiple tools in order to better understand the world around us and thus in turn improve society as a whole. Possible future projects were also outlined and these delved into the unknown. The real personal question which arose is: Where did all of this thinking originate?

In order to properly understand geoscience one has to delve into the past and see where the thinking originates from, how it has developed and consequently what has molded our thinking. It is critical to note that great geoscientists of the past were not necessarily geoscientists by classification and looked at problems from a holistic viewpoint. These great minds were keen observers, thinkers and in many cases philosophers and mathematicians with an interest in the world around them.

The Pyramids at Giza, in Egypt, are a prime example of the applied geosciences. The stones were sourced from another location, due to the fact that the designers knew of the ability of the material to withstand the elements. Furthermore the exact design, orientation and location of these ancient wonders allows one to believe that applied geological science was in existence some 3000 years before Christ, but nobody had the nomenclature in order to classify it. When standing in the presence of these structures, armed with this knowledge, one can only stare in awe and only imagine how, when and where the idea for these magnificent structures came about. Everything about these three large pyramids is amazing. This leads you to question whether the deeper understanding of the magnificent history of science could guide our future applications.


The Great Pyramids of Giza, Egypt (https://upload.wikimedia.org/wikipedia/commons/ a/af/All_Gizah_Pyramids.jpg)


When one looks into the annals of history we find that as early as 300 BC in Ancient Greece Theophrastus, who was a student of Aristotle and Plato, was examining concepts relating to geological science. He was a philosopher and deep in thought about processes on the earth. His ideas were guided by those of Aristotle who made critical observations of the slow rate of geological change. Furthermore his teacher also hypothesised what happens to water below the subsurface. It is interesting to note that the basis for earth science as we know it was deep thought observation and critical analysis.

Approximately 1300 years later Ibn Sina commented on the work of Aristotle and further delved into these surface processes, mountain formation, sources of water, formation of minerals and the origin of earthquakes. Thereafter Shen Kou, who was also a naturalist, proposed the modern theories of Geomorphology. This Chinese scientist, who dabbled in many fields, observed surface processes and the erosion of mountains as well as the consequent deposition of materials in the ocean. From a better understanding of these processes we have learnt to understand the formation of offshore mineral resources and thus extract them.

The initial applied use of geological science related to the extraction of resources, as previously mentioned. This can be seen from the oldest gold mine in the world in Georgia, which supposedly dates back to the third millennium B.C. This application in turn affected where we situate our dwellings, the materials used to construct these dwellings, as well as the relationship/impact we had with/on the immediate (surrounding) environment. It is a known fact that settlements were located along rivers in order to minimise the amount of time spent on collecting water. This life source also caused destruction when flooding occurred, yet we persisted to reside on the floodplain.


Panning for Gold (http://www.old-picture.com/american-adventure/pictures/panning-Miner.jpg)


More recently and closer to home, due to the groundwater resources supplying the majority of the country’s freshwater, Henry Darcy became the father of hydrogeology in 1856. He examined flow in saturated porous media in the water supply of Dijon, France and then announced a law named after him.

Thus heralded an era of French Mathematics, particularly applied to the earth sciences,  which we have never seen before. Charles Matheron, Benoit Mandelbrot and Pierre Gy all looked at problems related to understanding the earth. Thus it is clearly evident that a rich history of geoscience has lead to the point whereby we are at the cutting edge of great discoveries and intergration of knowledge. The future is so bright I have to wear shades!