Whats a continental rift?
Definition. A continental rift (Gregory, 1894; Quennell, 1982, 1985) is a fault-bounded elongate trough under or near which the entire thickness of the lithosphere (see Lithosphere, Continental ; Lithosphere, Mechanical Properties ) has been reduced in extension during its formation.
Is continental rift divergent?
There are two types of divergent boundaries, categorized by where they occur: continental rift zones and mid-ocean ridges.
Where is a continental rift?
Continental Rift Valleys Very few active rift valleys are found on continental lithosphere. The East African Rift, the Baikal Rift Valley, the West Antarctic Rift, and the Rio Grande Rift are Earth's major active continental rift valleys. The East African Rift is part of the “Great Rift Valley” system discussed below.
What is a rift valley also known as?
The area where the plates are pulling apart is called a divergent boundary. The valley floor is called a graben (sometimes used interchangeably with the term rift valley), and the valley sides are called horsts.
What is continental rifting quizlet?
continental rifts. – zones of lithospheric deformation & normal faulting. – form due to tensional stresses in the lithosphere.
What are continental rifts formed by?
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.
Is a rift valley convergent?
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.
How does a continental rift form?
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 is a rift in plate tectonics?
Rifting is defined as the splitting apart of a single tectonic plate into two or more tectonic plates separated by divergent plate boundaries.
What is a ridge rift?
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. The separate pieces continue to drift apart and become individual continents. This process is known as rift-to-drift.
Where is the rift valley?
Eastern Africa The Rift Valley, located in Eastern Africa, covers just over 2% of the continent and spreads over seven countries (Map 5 and Table 29). min. max. The Rift Valley consists of a group of independent interior basins, extending from Djibouti in the north to Tanzania in the south, nearly half being located in Ethiopia.
Which of the following are causes of continental 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.
Which of the following are causes of continental rifting quizlet?
Ascension of magma causes uplift of the crust. Stretching of the crust causes crustal blocks to drop into faults, forming a rift.
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.
What does a continental rift look like?
8:4510:39Continental Rifts, New Oceans, and Passive Continental MarginsYouTube
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.
Which of the following is characteristic of continental rifts quizlet?
The following are characteristics of continental rifting: Rifting begins with a broad uplift as magma ascends. Stretching of the crust causes crustal blocks to drop down. If rifting continues, the continent can be split into two pieces.
How are continental rift valleys formed?
Rifts are formed as a result of the pulling apart of the lithosphere due to extensional tectonics. The linear depression may subsequently be further deepened by the forces of erosion. More generally the valley is likely to be filled with sedimentary deposits derived from the rift flanks and the surrounding areas.
Which of the following are characteristics of continental rifting?
The following are characteristics of continental rifting: Rifting begins with a broad uplift as magma ascends. Stretching of the crust causes crustal blocks to drop down. If rifting continues, the continent can be split into two pieces.
How is a continental rift formed?
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.