Barberton and surrounds is a well trodden stomping ground for research geologists from all over the world.  They have been coming here for years to study evidence of the formation of the Earth’s first oceans and continents and some of the oldest know life forms. But there is new excitement about these mind-blowing, high-tech discoveries as they will soon become easily accessible to the man on the street through a user-friendly, roadside geological trail.

The Bulembu Road, stretching from Barberton to the Bulembu/Josefsdal border post with Swaziland, snakes for 45 kilometres through some of the most magnificent mountain scenery in Mpumalanga. When the road was reconstructed and tarred in 2009, many new rock faces were exposed displaying visually, spectacular geological features. 

Prof. Christoph Heubeck from the Geology Department, Freie Universität, Berlin, recently accompanied local scientists and members of Barberton Community Tourism (BCT) on a scoping trip along the road. He wrote his doctoral thesis on the ancient rocks along the length of the road 20 years ago.

According to Tony Ferrar, ecologist and member of the team working on the World Heritage Site, the purpose of this trip was to describe the most interesting and accessible geological features. Preserved in these rocks are, among many unique features, evidence of shallow, hot sea beds, the oldest tidal records on sandy shorelines, and the very earliest single-celled life forms.

When the first 10 kilometres was tarred in the 1980’s, a cutting into Saddleback mountain exposed soft white sandstone which today reads like a scientific time-capsule. In some detail Heubeck explained: “One of the wonders of the BGB is that the rocks are beautifully preserved. Here we can calculate moon phases on the beaches and tidal flats of 3.2 billion years ago. Visitors will be able to see evidence of the daily switching flows of tidal environments, and rapid, one-directional flows of rivers.  There are also still water sites where no movement disturbed the deposition of ancient sediments,” he said.

He further said that the early Earth turned much faster than today and the moon was much closer too. The moon’s gravitational pull resulted in much higher tides, shorter day lengths and lunar months half as long as those of today. The continents were probably flatter, the sea shallower and the coastal plains much more extensive with turbulent, high energy seashores. Nowadays tidal flats are only a few kilometers wide. When these rocks were laid down they probably extended for tens- to possibly hundreds of kilometers.

At that time there were no terrestrial plants, let alone animals, and the atmosphere contained various noxious gasses but no oxygen or carbon dioxide.
However, visible signs of early life are penciled as scratchy lines across the dove-grey sandstone. Heubeck calls it ”crinkly laminations” which are clearly visible in the road-side cutting, fossilized biomats of single-celled microorganisms.  Back then, it helped stabilize the sediments on a shallow, hot ocean floor. These biomats were possibly the only form of life for hundreds of millions of years, slowly, inexorably producing oxygen and carbon dioxide until more complex multicellular forms of life could evolve. And here they are just waiting to have their story told to every passing traveler.

“This geo-trail will open up a  new way in which we understand the very earliest part of Earth’s history and we are proud to have this is on our doorstep and entrusted to our care,” Ferrar said

The trail is one of the new visitor developments funded through the Barberton Chamber of Business’s Tourism and Biodiversity Corridor Programme. This programme also aims to support the Barberton-Makhonjwa Mountainland World Heritage Site which is currently in the planning stages.

“There is more information about the early Earth in these hills than anywhere else on Earth. I can think of no more deserving site for a geological World Heritage Site and wish you success in preparing the required Nomination Dossier for UNESCO,” Heubeck said.

Dave Mourant, chairperson of BCT said that this can only enhance what the area can offer to visitors. “We feel it is unique to be able to offer such a variety of attractions and will be marketing this with all our effort. Our thanks go to Prof Heubeck for his invaluable assistance on this trip and to other geologists who have worked to uncover these fascinating rocks and the facts about the early Earth“.

Dave Mourant, Prof. Christoph Heubeck and Tony Ferrar studying a map indicating the geological features on the Bulembu Road