Abstract. A continental rift is conventionally described as a thinning process of the lithosphere ultimately leading to the rupture of the continent and the formation of a mid-oceanic ridge. Rifting is the initial and fundamental process by which the separation of two continents into two tectonic plates takes place.
Which places offer examples of continental rifting?
- The Asunción Rift in Eastern Paraguay.
- The Canadian Arctic Rift System in northern North America.
- The East African Rift.
- The West and Central African Rift System.
- The Red Sea Rift.
- The Gulf of California.
- The Baikal Rift Zone, the bottom of Lake Baikal is the deepest continental rift on the earth.
Which is an example of continental rifting?
We begin with perhaps the best example of a modern continental rift zone – the East African Rift
What is an example of rifting?
The most extensive of the continental rift valleys are those of the East African Rift System, which extend northward to the Red Sea and eastward into the Indian Ocean. Other notable examples include the Baikal Rift Valley (Russia) and the Rhine Rift Valley (Germany).
What is an example of a continental rift zone?
Rift valleys occur at divergent plate boundaries, resulting in large graben structures and increased volcanism. The East African Rift is an example of a continental rift zone with increased volcanism, while the Atlantic’s spreading Mid-Ocean Ridge is host to an enormous amount of geothermal activity in Iceland.
What is the result of continental rifting?
Rifting is the process by which the continental lithosphere stretches. ... These zones have important consequences and geological features, and if the rifting is successful, lead to the formation of new ocean basins .
What causes continental rifting?
Where tectonic plates move away from one another the lithosphere thins. The underlying asthenosphere rises and expands like a hot-air balloon, elevating a broad region. If the plate is capped by thick continental crust , the resulting continental rift zone rises high above sea level.
What are the four stages of continental rifting?
They are: Katarchean-Archean, early Proterozoic, Late Proterozoic, Paleozoic, and Mesozoic-Cenozoic . Linear structures of the oldest stage combine features of development and structure similar to those typical of the rift and geosynclinal zones in the later periods of the Earth’s history.
Where do we see continental rifting today?
The rift today
Near that lake, rocks produced by the rift can be found on the surface of Isle Royale and the Keweenaw Peninsula of the Upper Peninsula of Michigan, northwest Wisconsin, and on the North Shore of Superior in Minnesota and Ontario.
What forms when two continental plates pull apart?
When two continental plates diverge, a valleylike rift develops . This rift is a dropped zone where the plates are pulling apart. As the crust widens and thins, valleys form in and around the area, as do volcanoes, which may become increasingly active.
How are rifts created?
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 . ... Two arms of the triple junction can split to form an entire ocean.
How are continental rifts and oceanic ridges similar?
Continental rift zones occur in weak spots in the continental lithospheric plate. A mid-ocean ridge usually originates in a continental plate as a rift zone that expands to the point of splitting the plate apart, with seawater filling in the gap.
What are divergent boundaries?
A divergent boundary occurs when two tectonic plates move away from each other . Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earth’s mantle to the surface, solidifying to create new oceanic crust. The Mid-Atlantic Ridge is an example of divergent plate boundaries.
What is a divergent rift?
Divergent boundaries within continents initially produce rifts , which eventually become rift valleys. ... This supplies the area with vast amounts of heat and a reduction in pressure that melts rock from the asthenosphere (or upper mantle) beneath the rift area, forming large flood basalt or lava flows.
What type of volcanism is common in continental rift zones?
Stratovolcanoes tend to form at subduction zones, or convergent plate margins, where an oceanic plate slides beneath a continental plate and contributes to the rise of magma to the surface. ... “Hot spot” volcanoes may form where plumes of lava rise from deep within the mantle to Earth’s crust far from any plate margins.
Is a rift valley convergent or divergent?
Areas where plates are colliding form convergent boundaries, and areas where plates are expanding create divergent boundaries . Rift valleys are formed by divergent boundaries that involve continental plates.
