(
:de: Horumersiel) with information board Kolks were first identified by the Dutch, who observed kolks hoisting several-ton blocks of
riprap from dikes and transporting them away, suspended above the bottom. The
Larrelt kolk near
Emden appeared during the
1717 Christmas flood which broke through a long section of the dyke. The newly formed body of water measured roughly 500 × 100 m and was 25 m deep. In spite of the repair to the dyke, another breach occurred in 1721, which produced more kolks between 15 and 18 m deep. In 1825 during the
February flood near Emden, a kolk of 31 m depth was created. The soil was saturated from here for a further 5 km inland. Kolks are credited with creating the pothole-like features in the highly jointed basalts in the
channeled scablands of the
Columbia Basin region in
Eastern Washington. Depressions were scoured out within the scablands that resemble virtually circular steep-sided potholes. Examples from the
Missoula floods in this area include: • The region below
Dry Falls includes a number of lakes scoured out by kolks. •
Sprague Lake is a kolk-formed basin created by a flow estimated to be wide and deep. • The Alberton Narrows on the
Clark Fork River show evidence that kolks plucked boulders from the canyon and deposited them in a rock and gravel bar immediately downstream of the canyon. • The south wall of
Hellgate Canyon in
Montana shows the rough-plucked surface characteristic of kolk-eroded rock. • Both the walls of the
Wallula Gap and the
Columbia River Gorge also show the rough-plucked surfaces characteristic of kolk-eroded rock. •
Oswego Lake, in the middle of
Lake Oswego, Oregon (a
Portland suburb), was an abandoned channel of the
Tualatin River that was scoured by a kolk. ==See also==