| GEOLOGY | At South Africa’s most recently appointed UNESCO World Heritage site, the earliest evidence of life on Earth is revealed in rock. Hlengiwe Magagula unlocks some of the geological treasures. NIVERSITY U ECK / JENA ECK / JENA B HEU H RISTOP CH Above, left to right: The Makhonjwa Mountains preserve pre-history in rock; visitors can see geologi- cal formations up close; a beautiful protea that occurs in these mountains. of ages IC B / BATO H TON-FYNC L Following the R40 between Barberton EY LANE, HAMI and the Swazi border, the Geotrail puts L the focus on unique geological features. LES 18 DISCOVER HERITAGE ISSUE 1 2018 ISSUE 1 2018 DISCOVER HERITAGE 19 | GEOLOGY | Barberton-Makhonjwa “This is globally unique, it’s the only place GeotraIL you can see these with the naked eye.” Geosites and view points NIVERSITY U A L U ECK / JENA ECK / JENA G B A G A HEU M H IWE G RISTOP EN L CH H Some of the geological features date back 340 million years and show what could be the earliest form of life known, a type of bacteria. t takes a couple of heart-thumping The winding R40 is a road I have travelled hours to climb to the summit of often, but the recent World Heritage accolade Emlembe, but it’s worth it. As you made me slow down and explore. Conveni- recover, you can sit in eSwatini (for- ently, this route from Barberton to the Swazi merly Swaziland) with your feet in border creates cuttings which expose features South Africa and admire the view that span the full period. The Barberton over the Barberton Makhonjwa Makhonjwa Geotrail was created in 2014 and Mountains – the most recently acclaimed it’s punctuated by lay-bys with displays telling The Barberton Makhonjwa Mountains World Heritage site stretches from Mountainlands IWorld Heritage site under the banner and the mind-bending geological story. Nature Reserve, located northeast of protection of UNESCO, the United Nations Earlier in the day I was lucky to be in Barberton, to just outside Badplaas, some Educational, Scientific and Cultural Organi- the company of Tony Ferrar, who, along with 70 km to the southwest. The Geotrail is the sation. This area has long been popular with geology professor Chris Heubeck, has liter- easiest way to see the range of geological geology geeks and its new status promises to ally written the book on the Geotrail (Barber- treasures protected by the site. put this little-visited corner of Mpumalanga ton-Makhonjwa Geotrail: Geosites and View on the tourist map. Points, Hamilton-Fynch for the Barberton This is my land; my ancestors tended cat- Tourism and Biodiversity Corridor or BA- tle on these slopes. Until recently, though, TOBIC). Tony was a member of the team, I’d no idea it was deserving of the ultimate led by BATOBIC and supported by funding accolade from the United Nations body from the National Department of Tourism, charged with protecting world heritage. who lobbied for World Heritage status. Their That’s because most of the treasures are work finally bore fruit at the World Heritage unseen, hidden below ground. I don’t mean Committee meeting in Bahrain in July 2018. minerals for mining. Yes, there was a brief Tony is primarily an ecologist and told me gold rush in the 1880s that created Barber- why this area is not just for geo-geeks. The ton, the town, and asbestos was, until re- rocks show evidence of what could be the cently, extracted at the Swazi border town of earliest form of life known. As the Earth Bulembu, which is where my climb started. slowly cooled and its crust solidified, chemi- The main reason these mountains received cal processes created the first life: primitive the much-coveted nod from UNESCO is forms of bacteria. At Site 5 (Dycedale Syn- IC that they embrace some of the oldest and cline) on the Geotrail, 8.2 kilometres from B best-preserved geological features on our Barberton, Tony showed me microfossil pat- / BATO H planet. To see anything comparable, I’d need terns, dark laminations in sandstone, that are to travel to Australia or Greenland. But the believed to be these bacteria. “This is glob- TON-FYNC L Makhonjwa Mountains, geologically known ally unique,” said Tony. “It’s the only place in as the Barberton Greenstone Belt, are much the world you can see these with the naked These rocks formed in the Archaean period beginning EY LANE, HAMI more accessible and diverse, allowing scien- eye.” (Even today, some bacteria are known L tists to study an unmatched 340 million to form biological mats called stromatolites LES some 3.5 billion years ago, when the Earth seethed with years of continuous geological activity. in shallow coastal waters.) > volcanic flows, and no life existed. 20 DISCOVER HERITAGE ISSUE 1 2018 ISSUE 1 2018 DISCOVER HERITAGE 21 | TOURISM | Timeline Consider this: if the Earth was, say, 24 hours old, we humans appeared at just 77 seconds before midnight. IC B That’s a mere 0.004% of the Earth’s history, and a lot / BATO H happened before our debut. TON-FYNC L 4.6 billion EY LANE, HAMI L years ago: LES the origin of the Earth Professor Christoph Heubeck explaining the origin and significance of banded iron formation. 3.8 billion years ago: first life arises The antiquity of these mountains is diffi- officially full, I took in the panorama of cult to take in. Three hundred and forty mil- grassy Highveld ridges, steep valleys shelter- 3.5–3.2 billion years ago: lion years give me the same vertigo as looking ing native forest and pine plantations. I had formation of the Barberton into the night sky and trying to comprehend a new appreciation for the epic cycle of life Supergroup the universe. These rocks were formed in the represented in these ancient mountains. The Archaean period (see box below) when the minerals are essential for plants, feeding 1.1 billion years ago: Earth seethed with volcanic flows and no life the moist grasslands that are naturally fire- first sexually reproducing existed. (By comparison, the Himalayas are dependent and have very high biodiversity. organisms develop youngsters at 80 million years old.) And the plants and animals sustain us, too, Each stop on the trail had a story to tell. One of course. 475 million years ago: first serves as an outdoor museum with a repre- But for how much longer? If we don’t land plants appear sentative display of rock types. At another, Tony protect our natural heritage, and the whole splashed water on the surface of the most an- planet, we face extinction. As Tony said, “It 225 million years ago: the cient rock type to highlight tiny round features makes me wonder whether in a million years dinosaurs evolve that he described as “volcanic hailstones”. to come, there will be any evidence of hu- 150 million years ago: first Reclining on my montane grass tuft, brain man existence in the geological record.” Above: A geologist’s pick, a type of hammer used to birds take flight split rocks, indicates scale in the photograph. Below: 130 million years ago: first Rock formation decoded Bands of iron-rich chert and haematite represent flowering plants evolve If you thought the Barberton Supergroup was an entry for Idols, you’ll be better informed the ‘rusting’ of the Earth, after a visit to this new World Heritage site. The Barberton Supergroup refers to the region of when oxygen bonded with 65 million years ago: ancient rocks now protected in the Barberton Makhonjwa Mountains. Here are some terms dissoved iron to settle on dinosaurs and ammonites that you will get to know: the seabed. become extinct • Archaean period. Some 4 billion to 2.5 billion years ago and the time of the first rock formations, and first evidence of single-celled life on Earth, fossilised bacteria. (Prior to the Archaean was a 14 million years ago: the period known as the Hadean.) first great apes appear • Barberton Supergroup. This is also known as the Barberton Greenstone Belt and comprises three 2.5 million years ago: the age-separated sub-groups: Onverwacht (oldest, mostly volcanic); Fig Tree (sediments and volcanic); genus Homo evolves and Moodies (youngest, sandy sediments). • Black chert. A hard, fine-grained sediment composed of crystallised silica. 1.8 million years ago: • Pillow lava. Rock formations resulting from the extrusion of lava under water. Homo gautengensis, the • Stromatolites. Microbial mats formed in shallow water by cyanobacteria. earliest-known South African • Subduction. The process where a tectonic plate moves under another. hominin, walks the Earth • Transvaal sediments (the Highveld). These buried the volcanic rocks for 2.5 billion years – protecting from both erosion and subduction. In geological terms, they are now eroding fast. This NIVERSITY U 43 000 covering was eroded off only during the breaking up of Gondwanaland, 180 million years ago. • Volcanic lapilli. Little ash-balls that fell from the air during volcanic eruptions. years ago: ECK / JENA ECK / JENA B • Volcanic rock. The Barberton Greenstone Belt strata were deposited horizontally in volcanic flows HEU Earliest evidence of humans H and later squeezed and folded by horizontal pressure from rising granite plutons (rocky outcrops). mining (in Ngwenya, Most strata are now nearly vertical. After folding, the whole mountain range was buried by RISTOP CH Swaziland) sedimentary layers. www.bbc.co.uk/nature/history_of_the_earth 22 DISCOVER HERITAGE ISSUE 1 2018 | TOURISM | SA’s World Heritage Sites The Geotrail offers magnificent views of The Barberton Makhonjwa Mountains World Heritage site is the mountainscape while interpretation the first in Mpumalanga, and the second geological site in boards shed light on the geological features South Africa after the Vredefort Dome.