Rippelmarken,Trockenrisse und andere Seichtwassermerkmale im Buntsandstein von Helgoland |
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| Authors: | Jens Bruun-Petersen Prof Dr Wolfgang E Krumbein |
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| Institution: | 1. Institut for almen Geologi, ?stervoldgade 5, DK-1350, Kopenhagen K, D?nemark
2. Universit?t Oldenburg, Postfach 943, 29 Oldenburg
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| Abstract: | Outcrops of the “Volpriehausen”- and “Detfurth-series” of the “Mittlerer Buntsandstein” (Lower Triassic) at Helgoland have been examined on sedimentary structures. Measurements of ripple marks were done. The analysis of the measured ripple marks and calculation of some characteristic parameters indicate that almost all ripples are oscillation ripples and allow no indication of flow directions. The size of the ripplemarks gives no direct indications of water depth. Mud-cracks, calcareous thin layers probably produced by algare mats and the occurence of evaporitic halite and gypsum deposits give better indications on water depth. The degree of asymmetry of the ripple marks may have some paleogeographic meaning and possibly indicates the Ringköbing-Fünen-ridge as a coastal area at the time of deposition. |
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