Some people may complain that German natural landscape is rather unspectacular. The North Sea and Baltic Sea in the north, some mountains in the south and not so much in between. Well, for those who may think like that I strongly recommend a visit to the… Harz region!
Why is Harz so interesting and why am I writing about it on the Sand Atlas website? The answer is because Harz is maybe one of the most geologically diverse region in Germany with dramatic changes within very small areas (from here the nickname “Classic Geological Square Mile”). Nowadays Harz is a low mountain range stretched over 180 km long and 30 km wide with the highest peak, Brocken, at 1,141 m. Things get more exciting when we look back over several hundreds of millions years ago, when all continents were “glued” together forming one single piece of land called… Pangaea. At this time, Harz was located much closer to Equator than now, somewhere on the actual location of… Cairo. When Pangaea began to split in two super-continents (Gondwana and Laurasia), the water started to fill the gap between them. Also the Harz was covered by water and abundant sediments transported from the vicinity started to pile up on the sea bottom.
Reproduction of the Earth from Late Triassic (about 220 million years ago) showing the separation of Gondwana (in the south) from Laurasia (north) – source: Wikipedia Commons
Further on, various tectonic events caused the creation of faults and uplift movements, exposing the various rock deposits to the surface. Due to their high altitude the new formed mountains were quickly eroded (especially the upper new layers) and the underlying base rock was standing as low mountains. These processes led to the formation of numerous types of sedimentary, igneous and metamorphic rock deposits. Among the upper layers, most common are the argilaceous shales (German: Schiefer), greywackes and granite. and from the older ones, limestone and gypsum deposits.
Maybe so far nothing really extraordinary but, as I said before, the true beauty of Harz geological architecture is given by the density and diversity of geological formations. On small areas, massive metal ore deposits are for example accompanied by lignite and salt deposits, limestone beds or dolomite formations. This high availability of minerals and valuable elements gave the region important mining privileges for metal ores (Fe, Mn, Pb, Zn, Ar, Au etc) while the soft calcareous deposits provided the formation of many drip-stone caves and caverns.
During a four-day drive-and-camp trip in Harz we collected several samples and learned a lot about specific geological features. More details about the trip with large descriptions of individual locations are in preparation and will be posted within the next days.
The internet is also full of information about Harz but our preferred website is http://www.harzregion.de. The website is very informative and there you can download 18 leaflets in both German and English language (partly also in French) about the geological landmarks of the region.