Consider the following statements about erratics. 1. They are called ...
- They are called erratics because they are composed of materials entirely different from those of the region in which they are found. Such erratics are thus most useful in tracing the source and direction of the ice movement.
- Sometimes the erratics may be found perched in precarious positions just as the ice dropped them and they are then termed perched blocks.
- Examples of such blocks are commonly encountered in both lowland and highland areas in Europe, e.g. Silurian grits are found perched on the Pennines' Carboniferous Limestone. Their presence in large numbers is a hindrance to farming.
Consider the following statements about erratics. 1. They are called ...
Erratics
Erratics are large rocks or boulders that have been transported and deposited by glaciers. They are typically composed of materials that are entirely different from those found in the region where they are located. These rocks can range in size from small pebbles to massive boulders, and they are often found in areas far away from their original source.
Statement 1: They are called erratics because they are composed of materials entirely different from those of the region in which they are found
This statement is correct. Erratics are called erratics precisely because they are made up of materials that are different from the surrounding region. These materials are often distinct and can provide valuable insights into the geological history of an area. For example, an erratic composed of granite in an area where the bedrock is primarily limestone indicates that the rock must have been transported from a different location.
Statement 2: Such erratics are most useful in tracing the source and direction of the ice movement
This statement is also correct. Erratics are extremely useful in tracing the source and direction of ice movement. By studying the composition and characteristics of erratics, scientists can determine the type of rock and its origin. This information can then be used to reconstruct the movement of glaciers and ice sheets. The presence of erratics in a particular area can indicate the direction in which ice was flowing and provide evidence of past glacial activity.
Erratics can also help in identifying the extent of glaciation in an area. The distribution of erratics can give insights into how far the ice sheet extended during a particular glaciation event. By mapping the locations of erratics, scientists can create a picture of the past ice movement patterns and the areas that were affected.
Conclusion
In conclusion, both statements are correct. Erratics are composed of materials different from their surroundings, and they are valuable in tracing the source and direction of ice movement. These rocks provide important clues about past glacial activity and can help scientists reconstruct the geological history of an area.