Sedimentary rocks cover a large proportion of the Geopark territory. They locally reach notable thicknesses, are of various characters and ages, host interesting and scientifically valuable fossil record, and pose an important source of minerals including water. Besides, weathering of sedimentary rocks generates a number of features attractive for geotourists.
Paleozoic deposits of various characters can be found especially in the northern and eastern parts of the Geopark. Thick successions of phyllites (so-called roofing slates) can be found in the area of Železný Brod. They pertain to the Krkonoše–Jizera Crystalline Complex and are usually greyish-green or purplish in colour.
In the Paleogene and Neogene (formerly referred to as the Tertiary), the Geopark territory was rather a denudational area. Sediments of this age have not been reported from here.