The valley floor of Matk Cirque (which in older sources is also called the Jezera Valley) is filled by coal carried by flashy streams and glacial moraines, and the Jezera Creek has its source in the middle of the valley.
The Matk Cirque (Slovene: Matkov kot), in older sources also the Jezera Valley (dolina Jezera) is an Alpine glacial valley in Slovenia. The valley floor ranges between 800 meters (2,600 ft) and 1,000 meters (3,300 ft) in elevation. The valley floor is filled by gravel carried by flashy streams and glacial moraines. Jezera Creek has its source in the middle of the valley; below its spring it has carved out and narrowed the valley, creating the picturesque Lamotje Gorge in the limestone rock where it enters the Logar Valley. 
