Roraima

The meaning of Roraima in Pemon Indians language means ‘Mother of all Waters’. Sometimes it is referred as ‘Sacred Mountain’. Tepuy means mountain. Table mountains  in the south of Venezuela are the oldest rocks on the earth. Roraima was already ancient when the two continents of South America and Africa were linked as a part of the continent Gondwana. So the age of Roraima is like 1.8 billion years. Final shape of Roraima appeared from the ancient continent of Gondwana, wchich began  to break up in the late jurrasic 150 milions years ago as the Altlantic Ocean divided the South America and  Africa were heavily compressed and cemented  together by silica reached a thickness of several  thousands metres – the quartzite and sandstone rocks known today as the Roraima Formation. The frequent occurrence of ripple marks on freshly exposed surfaces indicates that sedimentation of the sandstone took place  in shallow seas or lakes.  The complex lack of fossil spores or macro fossils indicate a PreCambrian origin for these rock strata, before life appeared on planet Earth. When freshly exposed the sandstone is whitish to reddish in colour, but weathered rocks are dark due to the blue-green algae or cyanobacteria that are able to survive on the porous surface. The inner forces that set the two continents apart helped to define the future shapes of the tepuys. Warping of the continental  plate created fissures and fractures on the surface of the Roraima Formation. This resulted in a erosion pattern, by weathering, which was accompanied by other tectonic forces within the earth, further uplifting and separating  the large isolated blocks tepuy that we see today. The plants on the summit of Roraima cling precariously to life in crevices and deep clefts on the eroded rock surface or wherever the little soil  that exists can escape being washed away by heavy rain. In exposed areas, tight little cushions of endemic plants huddle together. Some plants had to discover a way to supplement their diet by trapping and digesting small insects, most had to evolve strategies for combating water loss and to anchor themselves effectively  on an inadequate substrate. Animals must survive in an environment with limited food supplies and cope with extremes of radiation and temperature. Ferns are the most ancient of land plants, dating back some 400 million years. In the deeper, wider gullies on Roraima, sufficient soil and debris of Tree Ferns, Cyathea, which grows up to 4 metres high, together with many other primitive plants, including Cycads, Lomaria  ancient cone bearing plants that have been around for 120 milliion years. There are small animals living on summit of Roraima: black frog, black tarantula, black butterfly. All of them have protecting colour to do not be visable but also to be protected against ultraviolet radiation. Black frog has its family in Africa, so this is also a proof about two continents being linked together in ancient time.