Difficulty: Easy
Correct Answer: Rift valley
Explanation:
Introduction / Context:
Many important landforms on the Earth surface are created by internal forces such as faulting and rifting. One classic landform in world geography is the long narrow depression that forms when blocks of the crust move apart or drop down along faults. These features are significant because they often hold lakes, rivers, and even human settlements, and they offer evidence for the action of plate tectonics within continents. Examinations frequently ask candidates to identify this type of landform by its correct geographic term.
Given Data / Assumptions:
- The question describes a linear shaped lowland lying between highlands or mountain ranges.
- It states that this feature is created by the action of a geologic rift or fault.
- Options include various landforms such as rift valley, canyon, plateau, basin, and delta.
- We assume standard textbook definitions of these landforms.
Concept / Approach:
When the Earth crust is stretched by tectonic forces, fractures called faults may form and blocks of rock can move relative to each other. If a central block drops down between two normal faults, the resulting elongated depression is called a rift valley. A rift valley is therefore a long narrow lowland between higher areas formed mainly by faulting and rifting. This matches the description given in the question exactly. Other terms like canyon, plateau, basin, and delta refer to different processes and shapes, so they do not satisfy all the conditions in the question stem.
Step-by-Step Solution:
Step 1: Focus on the key features in the description: linear shaped, lowland, and located between higher land or mountain ranges.
Step 2: Note that the cause is clearly mentioned as a geologic rift or fault, indicating crustal extension and block movement.
Step 3: Recall that a rift valley forms when a block of the Earth crust subsides between two roughly parallel faults due to tensional forces.
Step 4: Compare this with a canyon, which is usually a deep valley carved by river erosion, not primarily by faulting.
Step 5: Conclude that the correct term for the landform described is rift valley.
Verification / Alternative check:
A good way to verify this answer is to think of classic examples. The East African Rift Valley is a famous elongated depression that extends for thousands of kilometres, bordered by higher lands and mountain ranges on both sides. It has formed due to the pulling apart of the African Plate, with large blocks of crust dropping down along normal faults. Similar features are seen in parts of Iceland and other rift zones. These examples confirm that the term rift valley refers to linear lowlands created by rifting and faulting, exactly as described in the question.
Why Other Options Are Wrong:
Canyon: This is incorrect because a canyon is mainly cut by river erosion or glacial activity, often in resistant rock, and is not primarily the result of crustal rifting.
Plateau: This is incorrect because a plateau is a broad elevated flat or gently undulating region, not a lowland between higher areas.
Basin: This is incorrect because a basin is a broader low lying area that may collect water or sediments, but it is not necessarily linear nor specifically associated with rift faults.
Delta: This is incorrect because a delta is a depositional landform at a river mouth where sediment builds out into a water body, not a tectonic structure between mountains.
Common Pitfalls:
Learners sometimes confuse rift valleys with canyons or deep river valleys because both can be long and narrow. The key difference is the dominant process: rift valleys are formed by tectonic stretching and faulting, whereas canyons are mainly carved by erosion. Another mistake is to think of any lowland as a basin, even when the shape and cause clearly point to fault related origins. To avoid such confusion, carefully note keywords like rift, fault, and linear lowland when choosing the correct term.
Final Answer:
A linear lowland between highlands or mountain ranges created by rifting and faulting is called a rift valley.
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