Wengen formation
The Wengen Formation ( Italian Formazione di Wengen ) is a lithostratigraphic formation of the Middle Triassic in the Southern Alps . It is named after Wengen in South Tyrol.
history
The term Wengen layers was first used by HL Wissmann in 1841 to describe a terrigen-carbonate interval with dark gray to black color. It was described in more detail in 1879 by Johann August Edmund Mojsisovics von Mojsvár .
Definition and distribution area
The Wengen formation is underlain by Ladin volcanic rocks and the Marmolada conglomerate . The Marmolada conglomerate, which can be up to 1,000 meters thick, was formed mainly in the vicinity of the centers of volcanic extraction. This conglomerate is inconsistently assigned either to the Wengen Formation, as in the description of the Commissione Italiana di Stratigrafia, or as a separate formation, such as in the geological map of the Western Dolomites 1: 25,000. The Wengen Formation is laterally interlocked with the Rosszähne Formation and Marmolada conglomerates. In the hanging wall, the Wengen Formation is interlocked with the St. Cassian Formation . The formation is up to 400 meters thick.
The distribution area of the Wengen formation extends in the southern Alps from Lombardy to Carinthia .
description
The formation consists of an alternating layer of volcanoclastic sandstones, clays and marls. There are repeated interventions with banks made of reef detritus. In addition, as in the St. Cassian Formation, cipit blocks and breccias can be found.
Fossil guide
Plant remains and the Daonella lommeli mussel can be found in the clays and marls .
literature
- Autonomous Province of Bolzano-South Tyrol, Office for Geology & Building Materials Testing: Geological map of the Western Dolomites . Scale 1: 25,000, recorded 1992-2007.
Individual evidence
- ↑ Lorenz Keim and a .: Facies interlocking in the basin sediments of the Dolomites (Ladin-Karn): from the outcrop to the geological map 1: 25,000 PDF file ( memento of the original from November 26, 2015 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
