Glacial deposits have been found in Africa because present-day continents were once connected in one large mass near the South Pole. The conditions found in this frigid polar region would have led to glacial formation on Africa before plate tectonics moved it to its present position.
- Earths crust and part of the upper mantle are broken into sections. Glacier deposits often form at high latitudes near the poles. Explain why glacial deposits have been found in Africa. Glaciers were found in Africa because continents were connected and party covered with snow near the south pole long ago.
What does the presence of glacial deposits indicate about the continents?
The presence of glacial deposits can tell scientists that if the continents have not moved, it would suggest that an ice sheet extends from the south pole to the equator. It was known that when glaciers move across the surface of the earth, they leave marks, grooves and deposits on the rocks and in that area.
What is glaciation evidence?
The most apparent evidence is of course the glacial drift itself. Glacial drift refers to the rock material ground up and transported by a glacier and deposited by or from the ice (till) or in water derived from the melting of ice (outwash or lake sediment).
How did glacial deposits provide evidence that Pangaea had existed?
The glacial deposit provide evidence that Pangaea existed in countries like South America, Africa, Asia and Australia because they have ancient glaciation which is either a world ice age or that the continents were connected.
What evidence proved that South America Africa India and Australia were once covered by glaciers?
What evidence proved that South America , Africa , India, and Australia were once covered by glaciers ? -reversals of Earth’s magnetic field are recorded by rocks in strips parallel to the ridges.
What is the force that moves the continents?
The movement of these tectonic plates is likely caused by convection currents in the molten rock in Earth’s mantle below the crust. Earthquakes and volcanoes are the short-term results of this tectonic movement. The long-term result of plate tectonics is the movement of entire continents over millions of years (Fig.
What is a glacial deposit?
In geography, a glacial deposit is a glacial landform, created by big rock or stones deposited in the landscape when the glacier withdraws.
How does glaciation occur?
Glaciers begin forming in places where more snow piles up each year than melts. Soon after falling, the snow begins to compress, or become denser and tightly packed. It slowly changes from light, fluffy crystals to hard, round ice pellets. New snow falls and buries this granular snow.
What is the best evidence that a glacial erratic?
Rocks that are moved by the glacier but are of the same rock type are called ‘glacially-transported’ rocks. All glacially-transported rocks and erratics tend to show evidence of that glacial transport, with scratches (striations), rounded edges and polished faces.
What causes glaciation?
These fluctuations include changes in the shape (eccentricity) of Earth’s orbit, the tilt (obliquity) of Earth’s axis, and the wobbling (precession) of Earth’s axis. First, Earth’s orbit can be nearly circular, as it is presently, or more elliptical.
Is Pangaea a fact?
Modern geology has shown that Pangea did actually exist. In contrast to Wegener’s thinking, however, geologists note that other Pangea -like supercontinents likely preceded Pangea , including Rodinia (circa 1 billion years ago) and Pannotia (circa 600 million years ago).
What is glacial scarring?
Glacial striations or striae are scratches or gouges cut into bedrock by glacial abrasion. Glacial striations are usually multiple, straight, and parallel, representing the movement of the glacier using rock fragments and sand grains, embedded in the base of the glacier , as cutting tools.
How old were the glacial deposits Wegener found?
about 300 million years ago
How do we know that the continents were once joined together?
Wegener then assembled an impressive amount of evidence to show that Earth’s continents were once connected in a single supercontinent. Wegener knew that fossil plants and animals such as mesosaurs, a freshwater reptile found only South America and Africa during the Permian period, could be found on many continents.
What are the 4 evidence of continental drift?
They based their idea of continental drift on several lines of evidence: fit of the continents, paleoclimate indicators, truncated geologic features, and fossils .
What is the evidence that Africa and South America were joined?
To him, the presence of identical fossil species along the coastal parts of Africa and South America was the most compelling evidence that the two continents were once joined.