Although it is not karst, this terrain, when wet, can quickly compactify and form sinkholes.
Although it is not karst, this terrain, when wet, can quickly compactify and form sinkholes. This kind of terrain usually contains a high concentration of (*) quartz, and most of its material is derived from finely ground glacial deposits. First used to describe the earth of the Rhine River valley, for 10 points—  identify this type of sedimentary soil consisting of silt-size grains loosely cemented by calcium carbonate.
Although it is not karst, this terrain, when wet, can quickly compactify and form sinkholes.
loess