Historical Bingen - Goethes "Urbreccie"

Johann Wolfgang von Goethe
Date of Birth: 28 Aug 1749
Place of Birth: Frankfurt a. M.
Died: 22 Mar 1832
Place of Death: Weimar

Classification: As a poet, dramatist, art historian, scientist and statesman, he was one of the best-known representatives of the Weimar Classical Period.

It was twice that J.W. von Goethe visited the Rochusberg in Bingen, on 16 August and on 5 September 1814, during the course of his cure in Wiesbaden.
He crossed the Rhine River by boat at Rüdesheim and described his impressions:

“Having left the boat we immediately noticed, with geological enthusiasm, strange rocks at the foot of the hill. Fortunately, there is a hammer at hand. A conglomerate is found deserving ultimate attention. A quartz rock, crushed at the moment of its genesis, sharp-edged the debris, reconnected by quartz compound. Enormous strength impedes collecting more than just small gravel. May soon a travelling natural scientist give these rocks a closer examination, determine their relation to the lower layer of the earlier mountain formation, send the news to me including some instructive samples! Gratefully would I appreciate it!”

Goethe remained dedicated to the fascination of this wondrous rock. On 5 September he examined the surroundings of the rock in order to clarify the genesis.

“We now turned to the sight never sufficiently viewed, then examined the rock. At the top it consists of a quartz which is similar to clay slate, at the foot towards Kempten there is some sort of Underlying Red, consisting of sharp quartz pieces almost without binder material. It is extremely solid and has gained the familiar outer chalcedony layer as a result of weather conditions. It is simply considered as primeval breccia.”

Goethe’s hopes for a more detailed evaluation of this primeval breccia were not fulfilled during his lifetime. However, his request to receive some instructive samples was obviously satisfied, since 4 pieces of primeval breccia from Bingen have found their way into his collection at his house at Frauenplan in Weimar.

According to Goethe’s descriptions 5 geological research papers were focused on the breccia in the following decades. None of them brought a final clarification of
the genesis.

Quartzite is an ancient rock, actually a metamorphosis of sand from the sea. It is frequently found in the southern part of the Hunsrück and Taunus.

Parts of the quartzite layer were subsequently lifted from the subsoil and formed by weathering. The primeval Rochusberg was shaped. In the dry climate at that time a talus slope was formed on the steep northern hillside of the mountain.
Millions of years later, a primeval forest grew at the Rochusberg, its roots releasing silicia into the ground. This process agglutinated the slope.

The talus slope was then covered again by later sediment layers during the following millions of years.

During the last ice age the Rochusberg was slowly freed from its deposits by the Rhine River. The silicified slope debris was exposed and split into blocks by weathering. This was the birth of the blocks of Goethe's "Urbreccia" which are nowadays visible.

Individual blocks of the primeval breccia are smoothly polished on the surface; Goethe assumed that the primeval breccia had a transparent coating of microcrystalline quartz, similar to the shiny glaze on pottery.

Actually, this polish originates from the ice age, caused by strong winds in connection with dry quartz sand, polishing the stone to have such a fine surface (it can be compared to modern sand blasting).

Studying the second information panel will reveal the complete process. In the following, you find the related questions.

Please send your solutions to GC1XD3C@drhh.de.

1. How old is the presented quartzite? ….. millions of years
2. When did a primeval forest exist on the Rochusberg? ….. millions of years ago
3. When was the genesis of the primeval breccia? ….. of years ago

Finally, you take a photo of the breccia and your GPS. You may now log, after my release.

Source: panels