Free State Geological Adventures in Pursuit of the Mundane

I have to avoid the temptation to discount the familiar.  I have lived with geology for 30 years of my life and it is part of my reality.  However I remember being enthralled by the new knowledge I had acquired when I first began this adventure as a student – suddenly the rocks on the patio took on a new significance, and I began to look at every outcrop I came across to try to determine the rock type and formation, and I venture that there is a new generation out there who would be very interested in the landforms and geology of what I sometimes relegate to the mundane. 

And so, without further ado, let us begin our adventures.

In search of new horizons and some space after a hectic year, I headed the truck in the direction of the Cape without thought of an ultimate destination.  However, averse to the trials of the Eastern Cape roads I opted for the grand sweep of the Free State and the vast landscapes of the Karoo.  Which if course forces one to drive the road up van Reenen’s Pass,  delivering one onto the high plateau which makes up the great African hinterland.  There is the usual mix up with trucks and motorists as everyone jockeys their way up the great escarpment, but while I dice with trucks I always find myself reflecting on the geology during the long climb to nearly 2000 m.  For those in the know, this escarpment is a result of Gondwana disintegration , formed in the order of 120 million years ago during one of the major ructions in Earth history.  So as we climb to the summit, consider that not only are we like mere ants in the vastness of the landscape, but also mere triflings in the immense passage of time.   

Let us take a closer look at the geology.  We are driving across sediments of the Karoo Supergroup, a vast pile of rocks that preserve nearly 200 million years of Earth history, ranging from rocks of glacial origin at the base to desert conditions  at the top of the pile.  Van Reenen’s Pass of course is near the top of this vast accumulation of sediments and those lofty peaks, so often wreathed in mist, are of Clarens Formation sandstones – which are the remnants of a fossilised desert of Saharan proportions. 

 Sandstones of the Clarens Formation

Dinosaur footprints and dinosaur bones are to be found preserved in the Clarens Formation.  Capping all of this are basaltic lavas which form the high Drakensberg.  Imagine an outpouring of lava on a continental scale – a veritable flood of incandescent, all consuming, molten rock flowing across an ancient desert floor, enveloping life, plants and water in its fiery embrace.   

 Dinosaur footprints in the Clarens Formation

Perhaps the best place to view some of this geology is the Golden Gate National Park, which was exactly on my way.  In fact I chose to make it so, for I am never one to pass up on an opportunity to take the road less travelled.  Golden Gate is indeed a gem not only in terms of its scenery but also its geology and accessibility thereof.  In many ways the geology is relatively simple, but there are some wonderful examples not only of the Drakensberg basalts and Clarens Formation sandstones, but the underlying Elliot Formation.  The Elliot rocks are remnants of ancient floodplain deposits and seasonally-flooded pans.  More than this, there are spectacular examples of dolerite dykes which can be traced for kilometres across country and which were the feeder pipes for the overlying basalts.  One of these is well signposted on the roadside.  Then there are faults to be seen in the road cuttings, and for those with some time on their hands the contact between the basaltic lavas and the underlying Clarens Formation sandstones is a must see – the very point where red hot lava met the shifting sands of an ancient desert. 

So now you know – the yellowish sandstones with their black staining which you see on the climb up van Reenen’s Pass are the remnants of an ancient desert, and the dark, resistant capping the first exhalations of lava as Earth went into convulsions as Gondwana began to pull apart.  Those basalts covered nearly the whole of southern Africa and extended into other Gondwana continents which is pretty awesome to say the least.

The Inaugural Blog

This blog has been a long time in its gestation, but there comes a time when there are no more excuses available.  An article a week will provide fifty two in a year, which in any bodies book is a massive amount of topical information.  So what is the aim of this blog?  In short, to provide students, scholars and teachers with a geographical resource that is fun, exciting, adventurous, entertaining and lastly educational.  Please note that the educational  part of this is stuck on the end on purpose, for in my opinion, if they subject matter doesn’t satisfy all of the first criteria, then we as teachers are doomed to failure.  For too long this subject, along with many others taught in schools, is couched in the dull language of the text book and the classroom, and I put it to us all, how can a subject that deals with our planet home and how it functions be anything but boring.  Watching waves breaking on a beach or a full moon rising are beautiful things and to be able to understand the mechanisms of our planet adds to this beauty.  The Afrikaans word for geography - aardryskunde, literally translates as the art/ knowledge/ lore/science of Earth’s riches is a fantastic summation of what the subject is about.

The amazingly rugged scenery of the Richtersveld National Park

I can remember those geography lessons back in our school days – most of them were tedious humdrum, learning about the Vaal Hartz irrigation scheme, or obscure terminology like yardangs, cuestas or geostrophic winds.  Fortunately I was fascinated spite of our teachers unstinting efforts to destroy any interest or excitement around the subject and so I persevered, got myself a good matric geography mark, and have now been a practicing geologist for over 25 years.  So there is hope for some of us yet.

I have to say I was fascinated by all of those fluvial and coastal processes, as well as much of the climatology which we studied.  I had a fantasy back then of sailing single handed around the world and learning about ocean currents called the West Wind Drift, or the Gulf Stream just fired up my imagination.  It was only in the last couple of years that I found a second hand copy of a wonderful book called Principles of Physical Geography by Arthur Holmes, and therein one can find our matric geomorphology curriculum.  Never mind the fact that those wonderfully named Paternoster Lakes, Drumlins and Hanging Valleys are only to be seen in recently glaciated terrains and mostly confined to the northern hemisphere.  Similarly for drowned coastlines and tombolas.  We were even taught about tectogenes as a mechanism for mountain building a decade after plate tectonics had consigned that theory to the rubbish dump of history.  We were indeed living in the age of enlightenment, with troops in the townships, disconnected teachers in the classrooms, and our future president languishing in a prison cell.  But that is another subject. 

Now if our erstwhile geography teachers had but stepped out of the front door they would have found a myriad of local examples to illustrate those dull textbooks and notes they were so in love with.  Our school was but ten minutes’ walk from the sea and was known for producing surfers and truants during the Gunston 500, which was the precursor of the Mr Price Pro surfing competition.  Surfers knew about waves, the rest of us read about them in text books.  Under our feet were ancient dune sands deposited there by winds that blew 100 000 years ago but we never went outside to dig in those red sands.  Cold fronts would roll through with wonderful regularity, mostly on the weekends it would seem, with all of the associated frontal weather patterns but we never went outside to see the mares tails and the changing weather patterns.  We could at least have installed a Stevenson Screen to measure rainfall, temperature, windspeed, barometric pressure and solar radiation.  It was much easier to keep the kids nose in their text books.  Around the greater Durban area are beautiful outcrops of sandstone, shale, dune sands, glacial deposits, coal reserves, faults, dolerite intrusions and granite domes all just begging to be visited.  You’ve guessed it, we  kept our noses stuck in our text books.  If we had only known about these things we would have demanded that our teachers take us to see them.  We did get to the top of Table Mountain in the Valley of a Thousand Hills in our Grade 10 year, and full marks to our junior geography teacher for organising that trip.  I remember being blown away by the stunning scenery and seeing the glacial striations which date back nigh on 300 million years.   

Striated Glacial Pavement outside Pietermaritzburg, KZN

I think I have made my point.  Perhaps one of the issues facing the teachers back then, and possibly even now, is that they couldn’t tell a sandstone from a mudstone, a granite from a basalt, and part of the aim of this blog/website is to provide teaching collections of rocks, Google Earth locations of some of our amazing geological and geomorphological features, photographs, movies and other on line resources.  But our first aim is to bring this subject alive, so we will go on adventures to different localities to see our wonderful and beautiful landscapes and try to explain them in a geographical way.  I am not going to be so hide-bound as to say, today we are going to learn about contours, or knickpoints, or cold fronts, but rather to observe the world and introduce topics as they arise on our travels.

• At this stage some of our proposed adventures include trips to:Sani Pass to look at one of the largest outpourings of basaltic lavas on Earth
• Golden Gate National Park to see beautifully exposed geological formations, faults, dykes, mass wastage, dinosaur footprints, dinosaur bones and magnificent scenery
• Wanderings through Lesotho to look at basalts, superimposed drainage, the dams at Katse and Mohale, Gondwana Erosion Surfaces, the Semonkong Falls and mountain scenery
• Thompsons Bay, KwaZulu Natal, is a geological gem, with sandstones, faults, coal seams and dolerite intrusions all within 500 m of one of the most fantastic tidal pools on Earth.  Anyone for a swim?
• Valley of 1000 Hills to take in the 1.1 billion year old granites and granite gneisses exposed in the valley floors, all capped by the Ordovician-Silurian age Natal Group Sandstone.
• Greater Durban, Cape Town and Johannesburg taking in the varied and amazing geology that underlies these three cities
• Blyde Rivier and the Eastern Escarpment
• Oudsthoorn to Prince Albert via the Swartberg Pass to take in mountain scenery, folded rocks and talk about rain shadows and the Little and Great Karoo.

The painted cliffs of Golden Gate National Park

 That I guess is enough to whet your appetites for the time being.  I have thousands of other ideas which we can discuss  further down the line, and of course are open to requests from you too, so I am looking forward to the ride. And while you are ruminating on my ramblings consider installing a weather station at school or in your backyard and get recording those temperatures, rainfall figures and barometric pressures.

Go here for some Pinterest images of geology and geography from around the world.  I am always adding to these so check back regularly for updates.