Visualising the ancient Karoo

I’m fascinated by dry places that were once at the bottom of oceans. The Karoo is such a place, at least for a period of its ancient history it was under water. During that time rocks formed when sediments sunk to the bottom of oceans and lakes. The sediments were transported from higher ground by glaciers and rivers into the Karoo basin.

Conceptual map of the rock formations, towns, and fossils of the ancient Karoo.

But the ancient Karoo wasn’t always under water. Towards the end of a 90 million year rock forming period, the Karoo became drier, until it resembled today’s Namib desert. Then, at about 190 million years ago, lava flows covered the entire Karoo putting an end to the rock formation period. The Drakensberg mountains being the striking remnant from that event, but the characteristic Karoo Koppies are also a consequence of the upwelling lava (sills) that infiltrated older sedimentary rocks (shales) on its way to the surface. The Karoo today is the result of a 190 million year erosion process that started after the lava flows.

I like to think of the Karoo as a book, the rocks are its pages, to read the story of the Karoo you need to know what to look at, and understand what it means. But the story becomes complicated quite soon.

How to represent the story of the ancient Karoo in a simple infographic? The result of my first attempt is a conceptual map plotting rocks, fossils, and towns. I visualised the Karoo basin as a saucer consisting of 5 layers. The oldest layers are at the bottom, and crop out on the surface at the edge of the saucer. Moving towards the centre the rocks become progressively younger. This is a distortion of the actual geography, but I find it a useful model to understand the order of events, and physical structure of the Karoo.

Interesting facts cropped up during my research that I’d like to explore further: the end of a glacial period led to the formation of the Dwyka Group, and evidence of a mass extinction at the end of the Permian is visible in the rocks of the Beaufort Group.

More to explore, and more to follow.

It’s Not Rocket Science

I helped the author Di Kamp transform her manuscript It’s Not Rocket Science into an ebook. But then she also wanted a printed copy. The design was never intended for print, but the result is looking good considering I designed for RGB and not CMYK.

I received a copy by post, it travelled all the way from Worcester in the UK to Cape Town, it’s a little rough for wear around the edges after the journey.

For the first time, instead of making the illustrations myself, I sourced them from The Noun Project, and I’m very happy with the result. The illustration shown here is by Garrett Knoll.

A beautiful design

Since reading Philip Hoare’s The Sea Inside I look at oystercatchers differently. He writes that the Eurasian oystercatcher:

…eats mostly mussels and cockles teased from the shore, using its greatest asset: a bone strengthened bill, part hammer, part chisel, able to prise open the biggest bivalves. Delicately coloured carrot-red to toucan-yellow – it might be made of porcelain – it a surprisingly sensitive probe. At its tip are specialised Herbst corposcules that allow the bird to sense its prey by touch as well as sight; an oystercatcher can forage as well by night as by day. Perpetually prospecting the beach, it stabs and pecks or ‘sows’ and ‘ploughs’, altering it methods to suit its prey.

what stayed with me is this:

It can even change the shape of its bill – the fastest-growing of any bird – morphing from blunt mussel-blade to fine worm-teaser in a matter of days.

Walking on the beach after a storm I picked up the body of an African oystercatcher that didn’t make it. Getting to see an oystercatcher up close is rare – and special – considering its wildness, holding it in my hands feels wrong somehow. They live on the edge always looking towards the sea – quick to fly when they sense people’s attention on them. They are not concerned with our world.

Recalling Philip Hoare’s words I studied the bill closely. It appears deceptively delicate, but considering that it is designed to withstand foraging abrasive mussel beds, the efficiency of its design is complete, allowing nature room to indulge in pure beauty.

More on African oystercatchers

According to the The IUCN Red List of Threatened Species there are an estimated 6000 African oystercatchers on earth.

The scientific name is Haematopus moquini. It means blood-foot (Haema: blood, topus: feet), named by Alfred Moquin-Tandon. Moquini’s blood-foot.

They are monogamous and can live for up to 35 years. Pairs have been observed to remain together for 18 years.

Afrikaans name: Swarttobie.