Understanding Glacial Deposits: Karewas Explained

The question asks about thick deposits of glacial clay and other materials embedded with moraines. This specific geological feature, found in certain regions shaped by glaciation, is known by a particular name.

Let's analyze the options provided to identify which one matches this description.

• Karewas: These are thick deposits of glacial clay and other sediments like sand, silt, and gravel. They are often found embedded with moraines, which are accumulations of debris carried or deposited by a glacier. Karewas are famously found in the Kashmir Valley. Their formation is linked to the deposition of materials in ancient lakes that existed in glaciated areas. These lacustrine deposits, interbedded with glacial till (moraine material), form the distinctive Karewa landforms.
• Bhabars: The Bhabar is a narrow belt located at the foothills of the Shiwalik range. It consists of pebbles and boulders deposited by rivers descending from the mountains. Water often disappears underground in this region due to the porous nature of the deposits. Bhabars are alluvial deposits, not glacial deposits.
• Duars: The Duars are floodplains and foothills in the eastern Himalayas in Northeast India around Bhutan. Like Bhabars, they are formed by alluvial deposits from rivers flowing down from the mountains, not glacial processes.
• Duns: Duns are longitudinal valleys that lie between the Lesser Himalayas and the Shiwalik range. These valleys are tectonic in origin but filled with alluvial deposits brought by rivers. They are structural and depositional features, but not primarily composed of glacial clay and moraines like Karewas.

Based on the characteristics described in the question – thick deposits, glacial clay, and embedded moraines – the term that fits perfectly is Karewas.

Comparing Different Geological Features

To further clarify, here's a comparison of the features mentioned:

As evident from the comparison, Karewas are distinct glacial deposits, aligning with the description provided in the question.

Revision Table: Key Geological Terms

Additional Information on Karewas and Glacial Deposits

Karewas are not just geological curiosities; they are economically significant. The fine-grained sediments of Karewas are very fertile and are particularly famous for the cultivation of saffron, almonds, walnuts, and apples in Kashmir. The study of Karewa deposits also provides valuable insights into the paleoclimate and geological history of the region, including past glacial cycles and lake formations. The thick layers represent long periods of deposition, preserving records of environmental changes.