A landscape formed due to a fissure in the Earth where one block has moved down relative to the other is known as which type of valley?

Introduction / Context:
Valleys are created by different geomorphic processes, including river erosion, glacial activity and tectonic movements. Understanding how each type of valley forms is important for physical geography and geology. The question describes a landscape produced by a fissure in the crust where one side has moved downward with respect to the other. This is related to tectonic forces rather than simple river or glacier erosion. The term used for such a feature appears in discussions of plate tectonics and structural landforms and is highly relevant for competitive examinations.

Given Data / Assumptions:

• There is a fissure or fracture in the Earth's crust.
• One side of the fracture has moved down relative to the other side.
• The resulting landform is a type of valley.
• Options include Rift Valley, U Shaped Valley, V Shaped Valley and Hanging Valley.

Concept / Approach:
A rift valley is formed when a block of the Earth's crust drops down between two faults due to tension and extension within the crust. This produces a long, narrow depression bounded by fault scarps. Famous examples include the East African Rift Valley and the valley of the River Jordan. In contrast, U shaped valleys are typically carved by glaciers, V shaped valleys by rivers and hanging valleys occur where smaller tributary glacial valleys meet a main valley at a higher level. Therefore, by matching the described tectonic movement of one block moving downward with the correct landform, we identify the feature as a rift valley.

Step-by-Step Solution:
Step 1: Note that the question highlights a fissure and differential movement of blocks of the crust. Step 2: Recognise that this description matches a faulted region where a central block subsides between two normal faults. Step 3: Recall that such down faulted depressions along faults are known as rift valleys. Step 4: Compare this concept with the given options and see that Rift Valley is listed as option A. Step 5: Choose Rift Valley as the correct answer since U shaped, V shaped and hanging valleys are associated with glacial or fluvial erosion, not faulting.

Verification / Alternative Check:
To verify, recall examples of each valley type. The East African Rift and the Dead Sea region are classic rift valleys formed by crustal extension. U shaped valleys, like those found in glaciated mountain ranges, exhibit rounded valley profiles carved by glaciers. V shaped valleys, such as young river valleys in mountainous regions, are sharply incised by vertical river erosion. Hanging valleys occur where a smaller glacial valley meets a deeper main valley and often host waterfalls. Since only rift valleys are directly linked to down faulting and block subsidence, this confirms that Rift Valley is the correct response.

Why Other Options Are Wrong:
U Shaped Valley refers to a valley carved by glacial action with a broad, rounded floor and steep sides, not by faulting. V Shaped Valley is formed mainly by fluvial erosion in the youthful stage of a river, again unrelated to crustal fissures and block movement. A Hanging Valley is a smaller glacial valley that joins a main valley at a higher level, often resulting in waterfalls. None of these involve a block of crust moving down between faults, so they do not match the tectonic description given in the question.

Common Pitfalls:
Students sometimes confuse rift valleys with deep river valleys or assume that any elongated depression is a rift. Another error is to pick U shaped or V shaped valleys because they are more commonly illustrated in school diagrams. To avoid such mistakes, focus on the key formation mechanism mentioned in the question: tectonic fissuring and downward block movement. Repeatedly revising the definitions, diagrams and examples of fault controlled landforms like rifts and grabens will greatly improve accuracy in this area of physical geography.

Final Answer:
A landscape formed by a fissure in the crust with one block moving downward relative to the other is called a Rift Valley, so Rift Valley is the correct option.