Blind valley意思

"Blind valley" is a term used in geology and hydrology to describe a valley or depression in the landscape that does not have an outlet to the open ocean, sea, or larger body of water. Instead, the water that flows into the valley accumulates in a lake or wetland, or it evaporates, infiltrates into the ground, or is otherwise not able to escape the basin.

Blind valleys can form in a variety of ways, including through the action of glaciers, rivers, or tectonic forces. They are common in areas with a lot of karst topography, where the underlying bedrock is soluble (like limestone) and water can easily dissolve it, creating caves and underground drainage systems. In these cases, the valley may have been formed by a river or stream that eventually found a path underground, leaving the valley without a surface outlet.

Blind valleys can also be found on other planets and moons, particularly those with ice caps or icy surfaces, such as Mars and the moon Europa. In these cases, the valleys may be formed by the flow of ice rather than water, and they can provide important clues about the geological history and climate of these celestial bodies.