The Amazon is a primordial giant of a river; a great dark snake, its head in the sea, its body coiling through thousands of miles of rain forest, its tail lost in distant mountains weathered in cloud. It is unbelievably old – scientists say it existed 60 million years ago – and unbelievably large. Its average out flow of 45 million gallons of water per second is greater than that of the world’s eighth largest rivers combined; it has over a thousand tributaries longer than the Thames; it drains an area the size of Europe; and locked up in its enormous basin is a third of world’s rain forest and two – third of its fresh water. Early explorers, astounded by the magnitude and complexity of AMAZON’s water ways, called it O RIO MAR, “THE RIVER SEA”-
How, you may wonder, did such a mighty river – system come into being.
GENESIS OF A RIVER:
Geologists tell us that in the youth of the world, about 150 million years ago, a great river flowed through what we now call THE AMAZON BASIN. This was not the Amazon as we know it; for one thing, it flowed in the opposite direction to today’s river – from ancient mountains in the East into the Pacific Ocean in the West.
Than, about 120 million years ago, when the dinosaurs were in their heyday, the great range of the Andes started to appear, levered up as a result of friction between two of the huge plates which make up the surface of the earth. As the Andes grew, they blocked the part of the primeral river so it was no longer able to flow into the pacific, and at the same time they enclosed its vast sea estuaries, cutting them off from the ocean. The river, however, continue to pour west wards, with the result that a huge inland sea, part salt water and part fresh water and almost the size of the Mediterranean, built up in what today is the AMAZON BASIN.
MARVELS OF THE AMAZON:
For tens of million of years, south America drifted in the oceans as an island continent, its plants and animals evolving in isolation, and developing into some of the most distinctive and varied life – forms on our planet.
Now where is the diversity more apparent then in the extra ordinary AMAZON BASIN, which originally developed as a huge island sea and which is now home of one of the world’s richest ecosystems. Here a single acre of forest may contain so many types of trees that only two or three examples of the same species recur; and here there are more species of the birds, bats, rodents and insects then on any other continent in the world. In fact, there are so many different creatures, and with such remarkable characteristics, that scientists are often at a loss as to how to classify them.
This inland sea endured until about 80 million years ago, when the entire continent of South America started tilting towards the east. Eventually it tilted so much that the water of its land locked sea spilled out through a gap between the high lands of Guyana and Brazil and found their way to Atlantic. The AMAZON was born at last, and was flowing to the East.