Did you ever ask yourself what is your city made of? I mean the historical buildings, there where concrete, glass or metal have not been in use as in today’s buildings. Well, I must confess that I didn’t think much about it. Until now. Because on this Friday evening we joined the annual “Dresden long night of sciences“, a great event where all research institutions in Dresden open their doors to the large public and show what they are doing.

Here we joined one short geological tour around the university campus under the guidance of Prof. Heiner Siedel from the Institute of Geotechnology at TU Dresden. Prof. Siedel led us through several geological highlights and explained with great engagement and professionalism the origins and utilization of natural stones in the urban architecture of Dresden.

Sandstone (Posta type in the lower area and Cotta in the upper part) and shale stone

The first stop was right behind the Hörsaalzentrum where we could examine limestone rocks used for the pavement of small walking alleys. Next, Prof. Siedel explained the differences between porphyry and granite stones on Mommsenstraße and then we moved to the rectorate building. According to our guide, the entrance is flanked by a special “porphyry tuff” originating from Rochlitzer Berg, an unique geological formation in Saxony. Our interesting tour went further down the Helmholzstraße and Prof. Siedel showed us how the local sandstone was used in the construction of the university buildings. As sandstone is very sensitive to weathering I could collect a few ml of real sand accumulated at the base of the wall. The last stop was also very interesting: shale stone used for a historical monument, rather unusual if we consider the typical use of shale especially for the buildings’ roof.

All in one, our short geological tour was really great, we learned a lot about Saxon limestone, porphyry, granite, volcanic tuff and shale stones and we are very grateful to Prof. Siedel for organizing this tour.