How is a rift different from seafloor spreading?
A rift valley is a lowland region that forms where Earth’s tectonic plates move apart, or rift. A rift valley is a lowland region that forms where Earth’s tectonic plates move apart, or rift. Rift valleys are found both on land and at the bottom of the ocean, where they are created by the process of seafloor spreading.
Does continental rifting cause seafloor spreading?
Incipient spreading In the general case, seafloor spreading starts as a rift in a continental land mass, similar to the Red Sea-East Africa Rift System today. The process starts by heating at the base of the continental crust which causes it to become more plastic and less dense.
What is a rift in the ocean?
In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Major rifts occur along the central axis of most mid-ocean ridges, where new oceanic crust and lithosphere is created along a divergent boundary between two tectonic plates.
What causes rifting?
Rifting can be caused when hot material from a mantle plume reaches the base of a continental plate and causes the overlying lithosphere to heat up. In addition to this the uwards movement of the plume against the base of the plate results in extensional forces, which can cause rifting.
Why is the Great Rift Valley important?
The Rift Valley has been a rich source of fossils that allow study of human evolution, especially in an area known as Piedmont. Because the rapidly eroding highlands have filled the valley with sediments, a favourable environment for the preservation of remains has been created.
What is the largest rift valley on Earth?
The largest and deepest rift valley yet discovered is not on Earth—it’s on Mars. Valles Marineris was formed millions of years ago, when the rocky Martian lithosphere was still rifting and shifting. Valles Marineris reaches depths of up to 7 kilometers (4 miles) and spans about 4,000 kilometers (2,500 miles) long.
Does the Great Rift Valley have volcanoes?
Researchers are to assess largely uncharted volcanoes in the East African Rift Valley, home to vast mammal migrations, mountain gorillas, spectacular peaks and fertile plains. The region’s volcanoes, numbering more than 100, are shrouded in mystery. Prior to its eruption, the volcano was believed to be dormant.
Did cavemen really live in caves?
Some prehistoric humans were cave dwellers, but most were not (see Homo and Human evolution). Starting about 170,000 years ago, some Homo sapiens lived in some cave systems in what is now South Africa, such as Pinnacle Point and Diepkloof Rock Shelter.
When did we stop being cavemen?
The Stone Age began more than two million years ago, and ended around 3300 BC, as humans began to discover metalwork with the dawn of the Bronze Age.