Which one of the following statements about volcanic landforms and drainage patterns is not correct?

Introduction / Context:

This question evaluates understanding of volcanic landforms and associated drainage patterns, which are important topics in physical geography and geomorphology. Volcanoes not only produce lava and ash but also shape the topography and control how streams and rivers develop around them. Recognising typical patterns, such as radial drainage on volcanic cones, helps in interpreting maps and landscapes in geography examinations.

Given Data / Assumptions:

• The question refers to stratovolcanoes, shield volcanoes and dissected volcanic cones.
• Drainage pattern describes the arrangement of streams in a region, often controlled by underlying geology and topography.
• A dissected volcanic cone is a cone that has been eroded by rivers and streams over time.
• We assume basic knowledge of radial drainage, where streams flow outward from a central high point like spokes of a wheel.

Concept / Approach:

Volcanic cones are typically isolated conical mountains with a central summit. Because they are high at the centre and slope outward in all directions, streams that develop on their flanks generally flow away from the summit. This produces a radial drainage pattern, one of the classic patterns in geomorphology. Even when a cone is dissected by erosion, the basic radial arrangement usually remains visible. Thus any statement that denies radial drainage around dissected cones contradicts well established geographic understanding.

Step-by-Step Solution:

Verification / Alternative check:

Standard geography textbooks and atlas diagrams consistently show radial drainage on volcanic cones like those in the Deccan region or volcanic islands. Even after prolonged erosion, streams still originate near the central highlands and flow outward. Field observations and satellite images confirm this pattern in many volcanic terrains worldwide. Therefore a statement that explicitly denies radial drainage on dissected cones contradicts both theory and observation, confirming it as the incorrect statement.

Why Other Options Are Wrong:

The statement about stratovolcanoes producing lava flows that move along valleys and can become resistant to erosion reflects the behaviour of viscous lava and subsequent cooling, so it is reasonable. The claim that surrounding areas can form highlands, lava ridges or mesas after erosion mirrors typical landforms left when softer materials are removed. The description of Hawaiian shield volcanoes being cut by streams that carve deep valleys with steep heads is well documented, for example on the islands of Hawaii and Kauai. The general statement that volcanic cones influence drainage is correct, since their conical shape controls the flow of surface water. Only the statement that drainage on a dissected cone is not radial goes against accepted knowledge.

Common Pitfalls:

Learners sometimes assume that heavy erosion completely destroys any organised drainage pattern, which may lead them to accept the incorrect option. Another pitfall is to focus too much on minor wording details in other statements rather than recognising the strong conceptual contradiction in the drainage pattern statement. Confusing stratovolcanoes with shield volcanoes can also cause hesitation, but the key to this question is the idea of radial drainage on cones.

Final Answer:

The statement that is not correct is: The system of streams on a dissected volcanic cone does not form a radial drainage pattern.