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Logging Tasks:
1) How many fenced off potholes can be found on Cove Rock?
2) What is the main rock formation of Cove Rock?
3) What is the geological word for a landform deposition that connects an island to the mainland, like a spit or bar?
4) What cements a fossil dune?
5) Optional - take a picture of yourself and GPS with Cove Rock in the picture or at any point of interest at this rock and post it with your log.
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A variety of seabirds live and breed there, including the endangered African black oystercatcher (Haematopus moquini). The rock provides ample whale-watching opportunities during whale season, and is an ideal fishing platform.
To get there
There are several ways to get to Cove Rock. Park at Hickman’s River (S33 04.182 E027 50.379) and take a 2.3km easy walk or park at Winterstrand (S33 05.633 E02747.665) and walk 3.3km eastwards to Cove Rock. Otherwise, there is the old route to get down to Rockcliff-on-sea (turnoff at S33 03.850 E027 49.012), which is the shortest distance to Cove Rock of 1.3km.
History
It is the historical significance of Cove Rock that draws both local and general visitors. It was previously known as Gompo Rock. Some of the earliest documented mentions of Cove Rock go back to 1687, when the Stavenisse was wrecked here and its sailors were rescued by the crew of the Centaur.
Cove Rock has also played an important role in Xhosa tradition, being regarded as a place of spiritual importance. Paternal ancestral spirits are said to reside in the water, and it is believed that ill people can be healed by visiting the cove. It was here at Cove Rock that the famous Xhosa prophet Makhanda (also known as Nxele) was going to call the ancestors from the sea to help the Xhosa nation drive away the white colonialists. But, according to Makhanda, the ancestors would only rise once he had jumped over a wide crack in the rock slab – a feat that was humanly impossible. Many people assembled on the beach on the day he was supposed to raise the ancestors to watch him jump, but Makhanda just sat staring at the gap. Late that afternoon the people started getting impatient, and demanded that he make the leap, but Makhanda continued to just sit there, deep into the night, without saying a word.
Geology
From Cape Padrone (just west of Cannon Rocks) north-eastwards the coastline is straighter with a narrower continental shelf. Because of the geological configuration, rocks run out to sea as reefs as far as Begha Mouth, whereas further north-eastwards the rock strata are almost level. All along this shoreline bi-directional parabolic dunes often forming wide dune fields are common. The sand of these dunes reverses frequently as the direction of the major winds is parallel up and down the coast.
Throughout the Eastern Cape coast, sandy beaches with occasional rocky outcrops predominate. Cove Rock is one such attractive promontory headland of aeolinite or dune rock. Other examples of promontories can be found at Woody Cape, Kwaaihoek, Kenton-on-Sea, Three Sisters and Nahoon Point. Lesser patches are found along beaches as far north as Cintsa and drowned ridges form reefs at sea. The greatest extent of aeolianite occurs onshore of the wide continental shelf in the south from which more sand was derived.
The gross outline of the present Eastern Cape coast was formed at the time of the break-up of Gondwanaland (an extensive southern super continent composed of Africa, South America, India, Australia and Antarctica) which occurred towards the end of the Karoo period in Jurassic time, caused faulting, uplift and volcanic outpourings and resulted in intrusion of dykes and sills of dolerite.
Much later, Pleistocene Northern Hemisphere glaciations caused sea level fluctuations, which affected the Eastern Cape coast. During the glacial low sea levels, calcareous sands blew onshore and were deposited against any uneven ground. These dunes have been hardened by lime cementation to form aeolianite ridges that exhibit marked cross bedding confirming their dune origin.
SOME POINTS OF INTEREST AT COVE ROCK:
Low tide platform/rock shelf: Against cliffs or solid rock water acts hydraulically. The weight of the waves pounds the rock but the water, as it hits the rock, also compresses any air in cracks and joints. This air expands again as the wave retreats. The expansion-compression effects works exactly as a compression drill and widens weaknesses in the rocks. A rocky coast under wave attack develops cliffs with notches of maximum erosion at the base. These notches may become caves or even arches. When the top of an arch falls, the pinnacle is known as a stack. Wave action is concentrated at mid-tide level between high and low water. In this area, 2 m tidal range is the norm. The cliffs are cut back leaving a rock shelf or wave platform (beloved of fishermen). As this platform becomes wider, it protects the cliff from further direct wave erosion. Pools in the wave platform may be drilled by pebbles wedged in cracks and swirled to and fro. The potholes form exactly as those in the rocky beds of rivers.
Potholes: Chemical erosion also takes place especially on Beaufort Group sandstone and aeolianite. Above wave level, chemical salt spray erosion creates a rough surface of miniature peaks and hollows especially on lime cemented rocks whereas where wave action predominate, the rocks are smoothed and pools are widened by solution and in this case the resultant through holes that can be seen here.
Shells: Cove Rock is intimately linked to the human history of East London, and middens, containing limpet and mussel shells and sherds of pottery, indicate that it has been occupied in early times. The dune deposits are underlain by shallow marine, beach and estuarine deposits of the Alexandria Formation that abound in shelly gravels. These fossil seashells indicate a Miocene age (10 Ma) for the oldest dune cordon. Just west of the potholes one can find these seashells, high above the current sea level mark.
Fossil Coastal Dune: Cove rock is a fossil dune cemented by calcium carbonate, which forms dune rock in which large cross-beds formed by slip faces are well preserved. Cross-beds indicate that the winds that formed this dune blew from the south-west and east.
The Southern and Eastern Cape coast has been the site of many cycles of dune activity related to changing sea levels. There are fossil dunes and dunefields at altitudes of up to 340m above present sea levels (eg. Gerickes Point) and down to 108m below present sea level. In some places, dunes relating to several cycles of formation are piled up on each other. Fossil dunes are probably Pliocene in age (between two and five million years).
A tombolo: Tombolos are ridges of unconsolidated sediments (sand or gravel) that join an island to the mainland. They form as a result of longshore drift, which transports sediment along a beach but deposits it in the lee of an island. A tombolo joins Cove Rock to the mainland.
Acknowledgements:
A Field Guide to The Eastern Cape Coast - RA Lubke, GW Gess & MN Bruton
www.shorelinesa.co.za
Geomorphology of the Eastern Cape, South Africa by Colin A. Lewis