A lot of people ask how was Victoria Falls formed – this incredible waterfall was formed over thousands of years. How? The surge of millions of tonnes of water eroding rock has created its current appearance and position on the Zambezi River.
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The waterfall that is the major tourist attraction in Southern Africa, seen by thousands of sightseers every year, did not always look like it does today. The story of how Victoria Falls was formed over the ages and how it has evolved is a fascinating tale.
The waterfall has taken thousands of years and millions of tonnes of water to reach its current appearance and position on the Zambezi River. It is truly an ancient phenomenon that still creates awe in everyone who sees it.
The question “how was Victoria Falls formed?” is answered right here – read on for a full explanation.
In the Jurassic period of Earth’s evolution, volcanic activity in the region deposited thick basalt molten rock that then solidified. This was the start of the geology of Victoria Falls.
This bed of basalt is approximately 305 meters thick and the Zambezi River flows over this volcanic rock for 209 kilometers. This flat basalt sheet extends as a flat plateau for hundreds of kilometers in every direction surrounding the falls.
The Zambezi river widens considerably before reaching the waterfall. A characteristic of the river’s course is the many little islands dotted throughout its journey. These islands increase in number as the river nears the waterfall and are even found right at the waterfall’s edge.
A gorge is a narrow valley with steep sides, generally with a stream or river running through the bottom of it.
Gorges are formed by the intervention of several geological occurrences.
The most common gorge creator is erosion by water – exactly the method of creation of the Victoria Falls.
A gorge is the result of a change of rock type, generally a softer rock, at the site of a waterfall. The pressure of the falling water erodes the softer rock creating a deep scour in the earth. This erosion creates rockfalls that cut back into the earth eventually forming a deep chasm with steep sides – a gorge.
Now let’s find out how was Victoria Falls formed
During the solidification process of the basalt molten rock, large cracks in the hard basalt developed. These cracks were subsequently filled with a softer sandstone rock over time.
It is commonly surmised that movement in the earth in an earlier geological period changed the rivers’ original course from running south-east to a more solid easterly direction. This newly diverted river then winds its way over the hard basalt and the many cracks filled with softer sandstone.
With the Zambezi River finding its way from its source to the ocean on its new course, the erosive power of the currents did a lot of work on the river.
The seasonal water flow eroded the soft sandstone from the cracks or basalt fissures. This removal of the soft earth from a large deep crack formed the first of many wide waterfalls that were still to come.
This repetition of this process created the zigzag gorges that originally were seven previous waterfalls.
Bear in mind that the erosion of the sandstone was a very slow process, taking hundreds or thousands of years in some cases, to form a waterfall.
The Victoria Falls formation we see today took place over a period of approximately 100 000 years.
There have been seven different waterfalls as the Zambezi River carved itself a path through the basalt rock of the plateau. This constant water erosion succeeded in pushing the current waterfall upstream by 8 kilometers from the original falls – creating a series of deep gorges.
This type of geology is a remarkable natural phenomenon. At Victoria Falls it can be seen in the zigzag formation of the gorges below the waterfall, which cover a distance of 150 kilometers downstream.
Looking at the sizes of these fissures it is safe to say that there has been a wider waterfall than the present one we see today. That is quite an amazing thought – that there has been a bigger waterfall than the one we see today.
The water torrent that gushes through these deep fissures creating rapids is considered to be one of the most exciting in the world, boasting some Class 5 rapids.
Today, we make use of the incredible depth and width of the gorge with high-wire and adrenaline activities for the thrill-seekers. These include the Victoria Falls gorge swing, Victoria Falls bungee jump, and zip line.
These gorges are also a haven for raptors who relish the wind eddies and vertical 125 meter high cliffs. These cliffs are breeding grounds for four species of endangered birds. The Taita Falcon, Black Eagle, Peregrine Falcon, Augur Buzzard, and the Black Stork appreciate these conditions too.
After leaving these narrow gorges, the river naturally widens out and slows down to its gentle meander through the African plains to Lake Kariba 200 kilometers downstream.
Finding out how was Victoria Falls formed is fascinating and it is a real work in progress too
Collectively these gorges are commonly referred to as the Batoka Gorge, but officially each gorge is numbered in order starting from the youngest, which is the current waterfall, known as the First Gorge. Each of these gorges represents a past site of a waterfall.
The Devils Cataract Falls on the far left edge of the falls is believed to be the start of the next fissure being eroded by the pounding of ceaseless water. This will cut diagonally behind the existing waterfall, meaning the current falls will become another gorge for the Zambezi River to thunder through.
This new development will demonstrate in real-time the geology of how was Victoria Falls created. Over the next hundred years, the ever-progressing erosion of rock from water flow will showcase the development of the gorges through time.
But whatever happens, the mighty river will continue to flow over the edge of a chasm and create an incredible sight for us to see for many, many years to come.
Victoria Falls was created when cracks in the hard basalt rock that makes up the plateau filled up with softer sandstone over the ages. With the shifting of plates in ancient times, the Zambezi River found its way over this plateau towards the sea. The currents and flows eroded the softer sandstone out of the cracks creating the waterfall.
The Zambezi River flows over the Victoria Falls. The river has its origins in Zambia and meanders down to the Indian Ocean with its delta in Mozambique.
The area of Victoria Falls has been occupied for over 3 million years. There is plenty of archaeological evidence to support this. That means that the Zambezi river would also have been present during this time period. However, the waterfalls have developed over the last 2 000 years.
There have been several names for the falls over time - these names depended on the tribes that were living there at the time. The Batoka called the falls "Shungu na mutitima". The Matabele named it "aManz’ aThunqayo" and the name we use today comes from the Batswana and Makololo tribes which is "Mosi-o-Tunya". All these name variations basically mean the same thing - “the smoke that thunders”.
Victoria Falls is approximately double the height of Niagara. This is not what makes the waterfall noteworthy, it is classified as the river with the largest sheet of falling water - not because it is the highest or widest waterfall in the world. It is classified as the largest, based on its width of 1,708 meters (5,604 ft) and height of 108 meters (354 ft) combined.