Updates & Events
Continental Glaciation
During the period of 1820-1850 the concept of the former existence of an ice age emerged which gave new insight into earlier climates, the shifting load on the earths crust, the changing sea levels and the circulation of sea water. Louis Agassiz was one of the first scientists to realize that an ice age had occurred.
It is well known that the northern portions of Europe and North America were covered with enormous sheets of ice during the Pleistocene Epoch, 1.3 million years B.P. to 10,000 years B.P., and that during this Epoch there were four glacial and three interglacial periods. It is perhaps less well known that various parts of the world were glaciated in such earlier times as the Permo-Carboniferous Period (250-300 million years B.P) and the Infra-Cambrian Period (600 million years B.P). The knowledge that parts of South Africa , India, South America and Australia were glaciated presented a real puzzle - How could these large, widely separated areas be covered by a continental glacier?
Geologists of the southern hemisphere welcomed the continental drift theory of Alfred Wegener in which he hypothesized that all the continents had formerly been joined in one large land mass; there was so much evidence that supported this concept. The distribution of the Glossopteris flora, other fossils, rock types and the pattern of glaciation could only be explained logically if this were the case.
In the period since 1956 with the increased knowledge of the Mid-Atlantic and other ridges, the discovery of the paleomagnetic lines and the development of the plate tectonics, we now know much more of the history of the physical world and the movement of the individual plates. We can look back to Permian times when all the continents formed one large land mass and we can note particularly that the southern continents were together. Now it is fascinating to see the validity of many of the ideas of Wegener, du Toit and other southern hemisphere geologists, and to see the mounting evidence of the spreading of a single continental glacier over the southern continents 200 million years ago. The glaciation of the southern continents can now be studied along with plate tectonics, the paleomagnetic lines and the age of the ocean basins to give a clearer picture of climates and events of the past.