A closed, steep-sided, and flat-floored depression in karst country. The sides are 2–10 m deep; the floor 10–1 000 m wide. Solution dolines form when solution enlarges a point of weakness in the rock into a hollow. Subsidence dolines form when limestone caves develop below insoluble deposits. The majority of dolines are corrosion forms.
http://www.speleogenesis.com/pdf/SG9/SG9_artId3297.pdf. A description of dolines.
Subjects: Earth Sciences and Geography.