Paternoster Lakes Formation
Paternoster lakes are a distinctive type of lake formation. They are characterized by being arranged in a sequence, often resembling a string of beads, along the floor of a valley.
Association with Glacial Troughs
These unique lake formations are primarily found in areas that have been significantly shaped by glacial activity. Specifically, paternoster lakes develop within Glacial Troughs.
- Glacial troughs, also known as U-shaped valleys, are formed by the erosive power of glaciers moving down pre-existing river valleys.
- As glaciers retreat, they leave behind uneven topography within the trough.
- Depressions, often formed behind bedrock steps or resistant rock bands (called 'risers'), fill with meltwater, creating individual lakes.
- When multiple such depressions occur along the length of the trough, they form the characteristic chain known as paternoster lakes.
Exclusion of Other Options
Other environments are not typically associated with the formation of paternoster lakes:
- Lava Plains: Formed by extensive lava flows, these areas lack the specific topography required for paternoster lake development.
- Piedmonts: These are gently sloping areas formed at the base of mountains, often by deposition from rivers or glaciers, but they don't typically host chains of paternoster lakes.
- Deserts: Characterized by extreme aridity, deserts lack the abundant meltwater and suitable depressions necessary for lake formation.
Therefore, paternoster lakes are a classic feature observed in Glacial Troughs.