Listening zone

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The Hörre in the geological map of the southeastern Rhenish Slate Mountains

The Hörre Zone is a geological unit in the eastern Rhenish Slate Mountains and at the same time in Central Hesse , which is named after the Hörre ridge in the Gladenbacher Bergland , below which its center lies. It stretches from the south of the Hohen Westerwald to the northeast to the Wollenberg , where it meets the Wetschaft depression and the geological Frankenberg Bay . The hearing zone is accompanied by a strip in front of it to the north of often cliff-forming quartzites , which in the broader sense is also included in the hearing zone.

overview

Geologically, the Hörre zone represents the most south-westerly foothills of the Hörre-Gommern zone , which is only a few kilometers wide and extends from the Hörre to the northeast via Kellerwald and Harz for about 300 km into the Magdeburg area. Rocks similar to those in the Hörre occur in the other parts of the Hörre-Gommern zone and are also very different from the rocks surrounding them.

The peculiarity of the Hörre zone lies in a sequence of strata that differs greatly from the geological units of the same age and adjacent to the north and south. It has therefore been the subject of geological research since the first half of the 19th century.

location

The core area of ​​the Hörre zone lies immediately below the center of gravity of the Hörre in the Lahn-Dill district . From there it goes north-east over the Aar and initially runs to the lower Siegbach loop between Siegbach - Überthal and Bischoffen , from where the west of the customs beech is crossed in a north-easterly direction to Weidenhausen . They narrowed for a brief, east-facing section to continue in a northeasterly direction, about Gladenbach finally and its eastern districts, the eastern Hungert to reach and pass under until the Hörre zone after passing under the Lahn between Caldern and Sterzhausen to the flanks of the Wollenberg meets the Frankenberg Bay , where it is cut off by the edge faults of the slate mountains. To the east of the Damshausen peaks and south of the Wollenberg, on the northeast of the Hörre zone, there are also the center and the north of the Elnhausen-Michelbacher depression along with the eastern interface to the Marburg Ridge with the Marburg districts of Elnhausen , Dagobertshausen , Wehrshausen and Michelbach .

To the southwest of its core area, the Hörre zone crosses the Dill into the Dillwesterwald and initially extends as far as the Ulmbach valley between Beilstein and Holzhausen (both municipality of Greifenstein ) in the Oberwesterwald , where the rocks of the Hörre zone are interrupted by the basalt of the Hohe Westerwald . Meanwhile, an island-like remote extension of the Hörre zone extends further south-west to Mengerskirchen - Probbach in the Limburg-Weilburg district .

Also completely separated from the more or less closed distribution area of ​​the Hörre rocks is an outcrop of quartzite on the Lahn near Dietkirchen . Belonging to the Hörre was only proven in 1997.

Borderline

Seen from southwest to northeast, the Hörre zone passes under the following natural spaces :

In the extreme northeast, the eastern edge of the Marburg Ridge is touched and the Wollenberg is reached and the Wetschaft depression touched on its edges , each of which leaves the natural Westerwald .

The following list of places is primarily intended to provide information about the exact boundary of the Hörre zone - the geological classification is only of indirect importance for the places themselves.

In the following, the municipalities in the Hörre zone are listed, sorted from southwest to northeast. The locations describe the course of this zone, which is only a few kilometers wide and can hardly be defined without special maps. After the municipality name, there is a description of the location of the affected municipality relative to the municipality marker in brackets, while the location of the municipality is then possibly followed in brackets in brackets for the location of the municipality relative to the Hörre zone, provided that it is peripheral. In the following, “ exclave ” means the south-western part separated from the rest of the Hörre zone by the basalt of the Westerwald.

History of exploration

The similarity of the Hörre rocks to those of the Kellerwald and Harz was recognized early on. In 1865 G. Württemberger compared the rocks of Hörre and Harz with his field of work in the Kellerwald, and emphasized their similarity. Further research took place mainly in the Harz Mountains, where the rocks were placed in the Lower Carboniferous in 1877 . This classification was questioned by August Denckmann in 1889 , because of the occurrence of layers of the Silurian together with these rocks , he classified the whole sequence as the Silurian. Due to his influence as a royal Prussian state geologist, this view prevailed until the 1920s, when the classification in the Carboniferous could no longer be doubted due to the determination of plant fossils. The Hörre zone was also placed in the Silurian by those who worked on the geology of the Dillmulde , such as Johannes Ahlburg, who carried out the first geological mapping work in the Lahnmulde , and Wilhelm Kegel, who worked on the geology of the Dillmulde , and viewed it as an elongated saddle.

Rocks of the listening zone

The sediments of the Hörre zone of the Upper Devonian and Lower Carboniferous differ significantly from those of the neighboring Lahn (southeast) and Dillmulde (northwest).
A strip of limestone , silica slate and black slate runs centrally over the ridge of the Hörre towards the northeast, which is flanked to the southeast, and to a lesser extent to the northwest, by a strip of clay slate , sandstone , greywacke , quartzites and limestones .

The Hörre zone crosses the ridge of the Zollbuche mainly with clay slate, gray-wacke, conglomerates and limestone, while the eastern Damshausen peaks have a significantly higher proportion of silica slate and slightly less conglomerates.

The foothills southwest of the Dill are geologically similar to those of the core zone, but the central area there is significantly narrower compared to the flanking.

Individual evidence

  1. ↑ Hartmut Jäger: Sedimentology and biostratigraphy of the sub-carbonic quartzite sequence of the Hörre-Gommern zone in the Rhenohercynian . Ed .: TU Darmstadt. 2000 (dissertation, online version ).
  2. ↑ a b c Map of the geological structure areas in the Environmental Atlas of Hesse
  3. ↑ a b Geological map of Hesse ( Hessian State Office for Environment and Geology ) - PDF, 28 MB
  4. ↑ F. Wierich, A. Vogt: On the distribution, biostratigraphy and petrography of sub-Carboniferous sandstones of the Hörre-Gommern-Zug in the eastern Rhenoherzynikum . In: Geologica et Palaeontologica . tape 31 . Marburg 1997, p. 97-142 .
  5. ↑ Map service "Protected areas" of the BfN ( Memento of the original from December 19, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / www.bfn.de
  6. ↑ G. Württemberger: The Kulm or the lower coal formation in Hesse . In: New Yearbook for Mineralogy, Geology and Paleontology . Stuttgart 1865, p. 530-575 .