An introduction to Caves of Botswana

"The lime caves and gulleys of Botswana may yet provide evidence of the earliest humans to match discoveries in Olduvai, Omo or Gauteng. We also begin to see how people have adapted to different climates. Just a few thousand years ago the Okavango and Makgadikgadi formed one vast lake before they dried up into marshes and pans."

-From Ditswa Mmung by Neil Parsons

Reports of previous expeditions

Gcwihaba Caverns(Drotsky's Caves)

Certainly one of the wildest and remotest of all tourist destinations in Botswana is the Gcwihaba Caves. These beautiful caves are situated 50km south east of Aha Hills and are set in the same undulating Kalahari dunes. There are two unspectacular low ridges of sand-covered rock at the entrance to the caves, but an enchanting spectacular curtain of stalactites is the first of many wonders inside this fascinating formation.

AHA HILLS

Isolation, peace, Kalahari sunsets and glorious birds are not the only compelling features at the Aha Hills. They have an additional appeal because they are one of the few places left in Southern Africa which have not been extensively explored and documented. They are enigmatic and the question that most visitors ask is,’ What are the chances of finding caves, similar to Drotsky’s Cave, here at Aha Hills?’ After all, the geography of the areas is the same. Thus far no caves have been found, but two large sink holes have come to light. The holes, about 15 kilometres apart, measure approximately 55 and 35 metres deep respectively.

Wadoum cave, Kalahari .

Stalagmite with micro rimpools

Wadoum cave, Kalahari.

Hook type helictite developed on stalactite

Lobatse Caves

In south eastern Botswana 76 kilometres south of Gaborone. There are two known caves in this area. These caves occur within the chemical sediments of the Transvaal Supergroup which comprise dolomite that is interbedded with chert.

They occur in the same lithology as the South African caves which have important hominid fossils. Both Lobatse and South African caves probably experienced the same climatic and ecological conditions that led to their formation and deposition since they are in the same geological formations and geographical regions.

Koanaka Cave

Still in Ngamiland area, this cave has one entrance with wonderful deposits rich with fossiliferous breccia. The presence of stalactites, stalagmites and fossiliferous breccia makes the cave one of the great natural heritages of Botswana. It has several chambers. Research is still being conducted to establish the palaentological, paleoecological and palaeoclimatic conditions that this natural heritage has for Botswana.

Figure 2-6. Two fans of aragonite (on right and left) that join to produce interfingering crystals in the middle. Note how clearly individual needles of aragonite can be resolved in this image. Preliminary dating suggests that the age of this aragonite is in low hundreds of years.
   Image is a mosaic of two photomicrographs that were taken in cross -polarized light; field of view is 2.2 mm wide. Bone Cave, Botswana; Sample BC 97-14; thin section BC 97-14-2. Sample collected by Dr. George A. Brook.

Caving in Botswana

This was to be our final day of exploration. Myself and Ron Ritter had spent the last few days completing the exploration, surveying and photography of Bone Cave, a cave stuffed full of three million year old fossils, located in the second of the Koanaka Hills in Botswana's empty north west corner. Tim Longden, the man I suppose Oxford's sterile tones would dub as our Home Agent, had flown out to join us the previous day, and so avoided a rather perilous two day drive through the bush.

We arose at first light and by an hour after sunrise we had packed and were roll-starting the land rover in readiness for the day's journey. Our target was the third of the Koanaka Hills, some twelve kilometres to our south west, and almost on the Namibian border. We had viewed the hill from the air, confirming that it was indeed a dolomite outcrop, protruding like an island from the desert surface, and not just another sand dune. Its surface appeared badly broken up, with a lot of loose rock, and its size, only 200m long and 30m high, didn't inspire enthusiasm. However, its sheer location was enough for us, being one of the earth's most remote and unvisited corners; before us only the earliest map makers and the geological survey had disturbed this sparsely occupied bushman territory. Also this was the last place we had left to investigate, once we'd searched this hill thoroughly our project would be complete.

We arrived at the hill before the sun climbed uncomfortably high, and located a slope on which to stop the land rover. As we broke into a packet of peanuts Tim summoned me over to where he was sitting. He passed me a small stone flake, wanting confirmation that it was what he thought it to be, a stone age tool. It appeared to be, but as I tried to explain that as one cuckoo doesn't make a spring..., he placed two more in my hand. Obviously we had a site, but probably only thousands and not millions of years old. Nonetheless, this discovery vindicated our journey, guaranteeing the hill a right to protection as a national monument, and strengthening our case for gazetting an extensive protected area in the region. More immediately, it was mind-boggling to have such tangible evidence that thousands of years ago people were sitting here, resting and probably snacking in almost exactly the same manner us. Minutes later, the sound of "CAVE..CAVE..CAVE..CAVE..CAAAAAVVVE !", our official cave discovery call, resounded over the whole of the hill. Before me was the top of a dark hole that I had investigated to a depth of eight metres and the top of a large drop. This call resounded twice more in the next half hour as we continued checking the hill thoroughly; cave discovery wasn't meant to be this simple. We only made notes of the entrances we could get into easily, holes that might involve squeezing or digging would be investigated later only if need arose.

After an early lunch, we picked the largest entrance, donned our caving gear (hard-hat, lamps, shorts and T-shirt), and started our descent. We clambered down into a large entrance chamber, lit by several fissures back to the surface. In the corner of this chamber a dark hole beckoned, we climbed over a few rocks, and paused for eyes to adjust to the darkness. We were standing at the top of a long slope, our lights feebly lighting only our immediate surroundings, the only wall we could see was the one behind us, daylight diffusely filtering through the hole in it. "Wow" was all Tim could say as we carefully picked our way down the slope, Ron and I were equally gob smacked by the place even if not so expressive. Our way was blocked several times by short drops, each time we found an alternative route on. To our left was the top of a large breakdown pile, black gaps gaping down between the room sized boulders, to our right was a long steep drop.

Eventually our way was blocked by an eight metre drop in front of us; we seemed to be perched overlooking an arcade like passageway, 10m wide and 20m high, extending away to our right. The passage continued to the left in a much diminished form, but was accessible after a short boulder climb. The passage closed down after only thirty metres, but as it seemed that our days work was done, I noticed a promising crack in the far wall. Stooping through, I was greeted by darkness again. "Come and have a look over here" I called back; our heartbeats raced once again as it became clear that this was a parallel gallery to the previous, and obviously an equal to it in size. The two galleries merged with several others to form an impressively large chamber, over twenty metres high, and forty in diameter. Each of the galleries led off, some for as much as fifty metres, but each seemed to close down into banks of sand, bat guano or stal. There were a few nice pools of cave pearls, but these seemed trivial when compared to the !Wa Doum cave, but other than the boulder pile, it seemed we'd worked this cave out. Sitting down on a breakdown pile in one corner of the main chamber, chewing on some biltong, we reflected on our dilemma. The cave was impressive, of that there was no doubt. There was more to do in this cave than we could give time for now, the survey would take a day, then there were a few leads to look at, and photography. On the other hand there wasn't really enough to justify the time and cost of another trip out here, even if in our hearts we knew that wouldn't stop us. Getting up, I took a snooped right into the corner. Between the rocks I could see space, not the solid rock I was expecting. I called out "I think I've got something" as I dropped myself between the rocks. I found myself looking along another of the caves galleries, instinct told me that this one went somewhere. A couple of minutes later we were gathered around a most amazing find, Botswana's largest known underground lake. Actually it was a stal dam holding back about fifty litres, filled by the rains that had percolated through the forty metres of rock above, but still it was unexpected.

Two minutes later we found ourselves standing in another large chamber, again the merging point of several galleries. More gasps of awe, as we took in the scene. The chamber wasn't quite as large as the previous, but it appeared to have more passageways leading off it. The colour of the rock was particularly clear here, all the clean surfaces were a dark battleship blue. We started another systematic exploration, but found this wasn't so easy here. We found ourselves entering a large maze of passageways, and resorted to cairning our route. An hour here left us none the wiser as to the maze's layout, we hadn't even investigated the higher levels we could see up into in a number of places.

This was how we had to leave the "Blue Cave" that day; time and light was against us as we drove back to our camp that evening, but spirits were high. We had found over a kilometre and a half of cave that day, this was taken up to two when we returned a week later to complete our explorations, making it Botswana's largest cave. After two months of hard work in the field, this third cave was the icing on the cake for us. It may not have been the most spectacular, nor the most historically significant; we're quite sure that there are much larger caves waiting to be discovered; but to us the adventure of this caves discovery makes it quite unforgettable.
Paul Mann