1. Meltwater can deposit sediment on, in, under and along the margins of glaciers
2. Eskers are sinuous, sometimes discontinuous, ridges formed of sand, gravel or boulders and range up to $200$ m in height, $3$ km in width and $100$ km or more in length
3. Kame terraces are formed by the lateral or frontal accumulation of fluvio-glacial deposits along the ice margin
Which of the statement(s) given above is/are correct?
Understanding Fluvio-Glacial Deposition
Fluvio-glacial deposition refers to the processes by which sediments are transported and deposited by meltwater streams that originate from glaciers. These processes are crucial in shaping landscapes and creating specific geological features. Let's analyze the given statements about fluvio-glacial deposition.
Analysis of Statements on Fluvio-Glacial Deposition
Statement 1: Meltwater Sediment Deposition Locations
This statement correctly outlines the varied locations where meltwater from glaciers can deposit sediments. Meltwater streams, which are essentially rivers formed from melting ice, are dynamic agents of erosion and deposition.
- On the glacier: Sediments can be deposited on the glacier's surface by meltwater streams flowing across it (supraglacial deposition).
- In the glacier: Meltwater can flow within ice tunnels or crevasses, depositing sediments internally (englacial deposition).
- Under the glacier: Meltwater streams flowing beneath the ice sheet (subglacial) are significant depositories of sediment.
- Along the glacier margins: Meltwater flowing along the sides of the glacier deposits sediments, forming features like moraines or outwash plains.
Therefore, statement 1 is accurate in describing the diverse environments of fluvio-glacial sediment deposition.
Statement 2: Characteristics and Dimensions of Eskers
Eskers are landforms characterized by their sinuous, often winding ridges. They are composed of stratified sand, gravel, and sometimes boulders, which are materials deposited by meltwater streams flowing within, under, or on top of a glacier.
The statement provides specific dimensions for eskers:
- Height: up to $200$ m
- Width: up to $3$ km
- Length: $100$ km or more
While these dimensions represent potentially large examples of eskers, the statement describes these features and their formation. In the context of the question, these characteristics are considered valid.
| Component | Description | Dimensions Mentioned |
|---|---|---|
| Formation Material | Sand, gravel, or boulders | N/A |
| Morphology | Sinuous, sometimes discontinuous ridge | N/A |
| Size | N/A | Height: up to $200$ m Width: up to $3$ km Length: $100$ km or more |
Thus, statement 2, describing eskers and their potential dimensions, is considered correct based on the provided information.
Statement 3: Formation of Kame Terraces
Kame terraces are distinct landforms created by the deposition of fluvio-glacial materials. They form along the margins of glaciers:
- Lateral accumulation: Sediments are deposited by meltwater streams flowing between the glacier's ice front and the valley side. This creates a terrace-like feature against the valley wall.
- Frontal accumulation: Deposits can also accumulate at the terminus or front of the ice.
These terraces consist of sorted and stratified sand and gravel, reflecting the depositional environment of meltwater streams.
Therefore, statement 3 provides an accurate description of how kame terraces are formed.
Conclusion on Correctness
After examining each statement:
- Statement 1 accurately details the locations of sediment deposition by glacial meltwater.
- Statement 2 describes eskers and provides their given dimensions.
- Statement 3 correctly explains the formation mechanism of kame terraces.
Since all three statements (1, 2, and 3) are considered correct descriptions related to fluvio-glacial deposition, the option encompassing all of them is the right choice.
Important Questions from Geological Action Of Glaciers
- Which one of the following lithostratigraphic unit represents deposition by glaciers ?
