| Autor: |
Ufrecht, Wolfgang, Sachs, Peter M., Timmermann, Georg |
| Zdroj: |
Jahresberichte und Mitteilungen des Oberrheinischen Geologischen Vereins; April 1990, Vol. 72 Issue: 1 p359-390, 32p |
| Abstrakt: |
Since the fifties, geological mapping has been carried out in the urban area of Laichingen (Alb-Donau-Kreis, Mittlere Schwäbische Alb). Two WNW- ESE striking diatremes are obvious being 450m or 200m long and 70 or 15 m wide, respectively. Both the dykes are situated beneath the western to central part of the city. The tuffs are probably derived from a olivine-melilititic magma. They contain numerous inclusions of the basement, which was partially subject to granulite facies metamorphism. Calcareous sinters are known from the rim of these voIcanic veins and they appear as both massive to laminated and "Erbsenstein" crusts. Their existence owes to precipitation from low thermal water ascending along fissures as a result of pressure decline and degassing of carbon dioxide. The calcareous sinters are distributed along the slope between 773 and 755 m ü. NN and were cut by post volcanic erosion. The basin shape in the city area is also caused by erosion and has to be regarded as a "pseudomaar " . Calcareous sinters exposed on rise west of the city area have yielded 14 speeies of gastropodes and a middle Miocene mammal fauna (Astaracium MN 6 to 8) . |
| Databáze: |
Supplemental Index |
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