Reddish deposits of the Krkonoše piedmont ENG

Some sedimentary rocks in the Krkonoše Piedmont Basin have a striking orange or reddish-brown colour, caused by the high content of various iron compounds. The soils that form from these rocks through weathering are equally colourful, which can be seen especially in the spring, when the local fields are not covered by vegetation. These variegated colours are typical for Early Protozoan sandstones and siltstones, usually formed in the environment of alluvial plateaus by deposition from occasional flows and alluvial fans (Vrchlabí Formation) or also in occasional shallow lakes (Prosečné Formation). Sometimes they can also contain tuff (volcanic ash). Various sedimentary structures, e.g. ripple marks or mud cracks, appear quite commonly. You can see their nice samples in the Treasury of Gem Stones. However, no fossils are found in these rocks, probably not many plants grew in such an inhospitable environment and it did not attract any animals to stay. Apparently, a giant dragonfly flew here only occasionally, and cephalopods wandered along the banks of rivers and lakes, whose tracks and coprolites are rarely found there.