Former quarry in the Pingarten porphyry
The former quarry in Pingartener Porphyry is an abandoned quarry near Pingarten , a district of the municipality of Bodenwöhr in the Upper Palatinate district of Schwandorf in Bavaria .
location
The quarry is located about 400 meters southeast of Pingarten. It is part of the Upper Bavarian Forest Nature Park .
description
The abandoned quarry at Pingarten is in Bavaria the only major disruption in Permian - sediments and therefore has rarity value. The rock structures can be clearly seen on the quarry wall. The quarry opens Rotliegend- breccias (deposited feldspatreiches flood sediment), the so-called Erzhäuser arkose with fluorspar - mineralization . The rock consists of a fine-grained base mass with coarse mineral and rock fragments. Because of its resemblance to volcanic rocks, the sediment was mistakenly named Pingarten Porphyry . The steep rocks were dragged up at the pile fault on the northern edge of the Bodenwöhrer depression .
About 300 million years ago ( carbon ) the great Variscan Mountains towered up in Europe . Over the course of millions of years, wind and weather eroded these mountains more and more. During the Permian period (290–245 million years ago) the depressions and valleys between the mountain ranges were filled with rubble. The result was the poorly sorted and, due to a dry, desert-like climate, mostly red-colored layers of the Rotliegend. The red color comes from the iron hydroxide , which coats the debris fragments in the form of a thin skin.
Access ping garden
Porphyry structures are large inserts in an otherwise fine-grained matrix. The term porphyry is actually only used for igneous rock . The Einsprenglinge consist of large single crystals grown in the melt. The similar structural features of the Rotliegend sediments led to the (incorrect) designation "Pingarten porphyry".
The outcrop opens up the lower part of the Arkose ore houses. This brown-red rock consists of a fine-grained base mass (mainly silt and sand grains up to 2 mm in size) with embedded coarse mineral and rock fragments (up to 5 cm in size). The fragments consist of feldspar as well as quartz , mica and granite fragments . The rock is called arkose because of its high feldspar content. The arkosis is solidified by silica that was excreted in the pore spaces. Mineral dykes made of fluorspar (yellow, violet, green) and barite (white, pink) can also be found on fissures .
Archehouses Arkose
The Erzhäuser Arkose owes its origin to the transport through mud flows or stratified floods . This is understood to mean masses of mud and water that swell like an avalanche and that are created in mountainous desert landscapes by sudden heavy downpours.
Such episodic floods lead to rapid and largely unsorted deposition of the sediment load. Rocks of this type ( fanglomerates ) were deposited throughout Europe at the time of the Rotliegend. The ore houses Arkose is part of the filling of the Permian Naab Trough , a rift valley that was deepened up to 2800 meters and thus reached about the dimensions of today's Upper Rhine Rift .
Formation of the mineral ducts
The fluorspar and barite tunnels within the ore houses Arkose were formed around the same time as the neighboring tunnels of the Wölsendorfer fluvial district . Their age is dated based on isotope determinations with about 260 million years ( Upper Permian ). This also explains why the fluorspar corridors can never be found in the younger outer layers, e.g. B. found the triad .
The mineral veins are oriented in a similar way to the Wölsendorfer veins and the neighboring major fault of the "Bavarian pile". They were excreted from hot, hydrothermal solutions, which found their way upwards along newly torn deep fracture zones, where they penetrated the adjacent rock in a corridor.
Use of the Pingarten porphyry
The ore houses Arkose were mainly mined here intensively at the beginning of the 20th century and served as railway ballast. It was then replaced by the more suitable granite . Since then, the gravel has only been used in community road construction.
Geotope
The quarry has been designated by the Bavarian State Office for the Environment (LfU) as a geoscientifically valuable geotope (geotope number: 376A007). It was also awarded the official seal of approval for Bavaria's most beautiful geotopes by the LfU .
Web links
Individual evidence
- ↑ Location of the quarry in the Bavaria Atlas (accessed on October 25, 2017).
- ^ Bavarian State Office for the Environment, Geotop Pingartener Porphyr SSE von Pingarten (accessed on October 25, 2017).
- ↑ Bavaria's most beautiful geotopes, former quarry in the Pingarten porphyry (accessed October 25, 2017)
Coordinates: 49 ° 18 ′ 57.9 ″ N , 12 ° 19 ′ 42.6 ″ E