A sinuous ridge composed of sand and gravel is a Esker it is a deposit made by streams flowing in tunnels within or beneath glacial ice.
A long, twisting ridge of stratified sand and gravel known as an esker, eskar, eschar, or os—also referred to as an asar, osar, or snake kame—occurs in glaciated and formerly glaciated regions of Europe and North America.
Eskers are typically several kilometers long and resemble railroad embankments due to their consistent shape.
According to some theories, streams that flowed inside and beneath glaciers built the majority of eskers inside of tunnels with ice walls.
When the glacier was slow and sluggish, at the time of the glacial maximum, they tended to form.
Stream deposits remained in the form of protracted curving ridges after the restraining ice walls melted away.
Learn more about glacier here:
https://brainly.com/question/19709729
#SPJ4