Tessa’s pool is found at the end of a series of cascades on the Hadange River in the grounds of Outward Bound Zimbabwe.
It is a 30 metre high waterfall with a 25 meter circumference pool at the bottom. Complete with palm trees and a romantic rocky beach.
A great place to finish your hike. Well worth a visit even if you aren’t hiking.
Apart from this lovely place, there are plenty of activities including accomodation at OBZ up the hill. It is a great hub for your hiking and Mountain biking activities. There are also camping facilities here.
The Chimanimani Mountains and Tessa’s Pool: The Chimanimani Mountains straddling the elevated border between Zimbabwe and Mozambique hold a unique position within the geological history of the two countries. Zimbabwe itself might be thought of as a geological entity in that most of its surface area comprises an ancient stable block of granites and associated greenstone belts, which is referred to as the Zimbabwe Craton.
Surrounded by weaker zones of highly deformed and metamorphosed rock, the Craton has acted as a continental nucleus. The rocks making up the Craton have ages ranging between 3.8 and 2.6 billion years, reflecting its own tumultuous history of upheaval, intrusion, vulcanicity, consolidation, fracturing and stability. Some 1.1 billion years ago a period of stability allowed for the erosion of highlands and the deposition of sediments in intracratonic basins.
This process is reflected in the Chimanimani District in the accumulation and preservation of sediments of the Umkondo Group marginal to the eastern extent of the Zimbabwe Block. This almost flat-lying sequence of calcareous, quartzitic and shaly sediments is intruded by thick sheets of dolerite, and is appreciated as the impressive scarp overlooking the Save Valley to the west. The sequence continues up the Umvumvumvu and Biriwiri valleys to Skyline, or through Cashel to Tank Neck from which two points one appreciates the vista of the Chimanimani Mountains that create the eastern border of Zimbabwe in this location.
The Chimanimani Mountain chain, which towers above the Haroni Valley, is a contrasting, north-trending rampart of resistant sugary quartzites and mica schist overlying a floor of granitoid gneiss. Originally thought to be older than the Umkondo sediments, the expression was referred to as the Frontier Series. Geological mapping has shown that the metamorphosed Frontier sediments are similar in age and that they form a basal section to the Umkondo Group. However, due to deformation and uplift within the Mozambique Metamorphic Belt to the east, the eastern sediments were themselves deformed, metamorphosed and were caused to slide westwards onto and into the bastion of the Zimbabwe Craton with its overlying sediments. This collision with resistance took place more-or-less along the south-flowing line of the Haroni River causing the ferruginous (iron containing) shales and quartzites to be uplifted to incline at about 45 degrees to the west where they form the backbone of what is referred to as the First Range.
It has been this thrusting along a basal flat-lying plane that has caused exposure of a narrow conglomerate horizon that is host to the ancient alluvial diamond deposit discovered adjacent to the Haroni River on Charleswood Estate. The movement of hydrothermal fluids along the same dislocation may also have been the source of gold that is now found in superficial concentrations above dolerites across Tarka Forest. Continued pressure from the zone of upheaval in the east caused the Frontier quartzites to be thrust progressively against the resistant block where they rode over themselves and were over folded into slices in which movement was preferential within zones of soft micaceous schist.
This mountain-building process resulted in the topographic uplift what we now appreciate as the Second and Third ranges of the Chimanimani Mountains in Zimbabwe, where the basal thrust on a gneiss floor is seen looking east into Mozambique from Skeleton Pass and is again exposed in the west passing through the Outward Bound School and extending south towards the lower Haroni Valley. Google Earth imagery clearly differentiates between the rugged quartzite slices and more subdued, grass-covered schist plains that characterize the intervening Bundi Valley, whilst the ‘Aerodrome’ is the core of an overthrust (flat-lying) recumbent fold.
Google Earth images also show clearly the imposition across all of these rocks of a series of east-north-east trending linear fractures, the most prominent being the Zunguni Fault, which passes through Skeleton Pass, crosses the head of the Bundi Valley to control the Hadange gap and stream down to the Haroni River below Outward Bound, and thence continues through Charleswood farm and across the saddle in which Chimanimani Village nestles. This is a major fault line having a relationship to the lines of weakness through the Limpopo Mobile Belt to the south. A splay from this fault follows the Haroni River just north of the Outward Bound entrance gate, passes through Tessa’s Pool and continues up the cleft towards Peza (Ben Nevis) peak behind the School. The result is the displacement of blocks of quartzite, a feature that is also clear on the Google image.
The consequence of the uplift described is erosion, and the sculpting of the face of the Chimanimani massif as we know it today. This is primarily through the action of rainfall and runoff that provide the means for the work of rivers. Locally the high border peaks of Peza and Binga form a watershed that passes across the saddle of Skeleton Pass. Watercourses take the line of least resistance, the soft schists in the case of the Bundi, and the ENE fracture trends in the case of the Hadange and upper Haroni rivers. The massive U-shape of the Hadange Gap with bounding cliffs of the ‘Sphinx’ is immediately apparent on approaching Outward Bound. However, in situ rock exposure is lacking in the valley itself, extending through the Outward Bound School and into the Haroni River where it crosses the wetland area downstream of Tessa’s Pool. On closer examination large and chaotically placed boulders of quartzite are bound together in a matrix of rubble and clayey soil. This is the product of a massive landslide that has fallen out of the Hadange Gap, probably triggered by earthquake activity.
The gnarled quartzite is intact behind the School, and provides the faces that allow for rock climbing, abseiling and mountain rescue practice. It is this quartzite face that the waterfall at Tessa’s Pool defines. It is the point of resistance that the Haroni River has met in its quest to erode down to a base level, seen in the subdued gradients downstream of the Pool. From the photograph of the Pool and fall, it would appear that the right or north bank of the river carries the soft fracture zone of the Zunguni fault splay, whilst the waterfall itself is directed over the less fractured quartzite. The river upstream tumbles over a series of falls, rapids and through intervening pools as it continues to erode down to its base level.
Acknowledgements:Geological information kindly supplied by Tim Broderick of Harare. Photography courtesy of Lucy Broderick of Harare
TASKS FOR LOGGING A FIND
1) What type of rock is behind the waterfall?
2) How high is the waterfall?
3) What is the diameter of Tessa's Pool?
4) Who was Tessa?
Please answer via my geocaching profile and I'll authenticate your visit.