1. The Pliocene and Quaternary fluvial archives of the Rhine system
- Author
-
Wolfgang Boenigk and Manfred Frechen
- Subjects
Archeology ,Global and Planetary Change ,geography ,geography.geographical_feature_category ,Pleistocene ,Marker horizon ,Fluvial ,Geology ,Paleontology ,Terrace (geology) ,Loess ,Glacial period ,Tephra ,Quaternary ,Geomorphology ,Ecology, Evolution, Behavior and Systematics - Abstract
The River Rhine is one of the few major fluvial systems that connect the areas of the Alpine glaciers and Scandinavian ice sheet and so provides a key for correlating the two glacial areas in northern and middle Europe. The fluvial sequences of the Rhine Valley include at least 11 Pleistocene terraces in the Lower Rhine area, 2 Pliocene and 12 Pleistocene terraces in the Middle Rhine area resulting in 15 different Pliocene and Pleistocene terraces based on the correlation between Lower and Middle Rhine. The formation of fluvial terraces is significantly influenced by climatic and tectonic processes. The terrace staircases are a result of uplift in the Middle Rhine area and the southern part of the Lower Rhine area, whereas subsidence in the northern part of the Lower Rhine area resulted in buried stacked sequences. Magnetostratigraphic data provide chronological constraints for the terrace deposits in the Lower Rhine embayment and Middle Rhine region. The Matuyama/Brunhes boundary is a reliable marker horizon for the Upper Terrace fluvial deposits exposed in the Karlich clay pit in the Middle Rhine area. The first appearance of volcanic heavy mineral grains in the terrace sediments, in loess and soils can be correlated from the Middle Rhine area through the Lower Rhine embayment to the Netherlands. The first occurrence of Nordic components in terrace sediments of the Lower Rhine area is known from gravel on top of the Kempen-Krefeld beds and so are younger than the Holsteinian but older than the penultimate glaciation. In the lower Middle Rhine area, 40Ar/39Ar dating of tephra layers intercalated in the aeolian and fluvial sediments provide age constraints. The Upper Pleistocene aeolian sediments overlying the terrace deposits have been dated by luminescence methods, and the tephra from the Laacher See eruption (12,860 BP) is present in the Younger Lower Terrace deposits.
- Published
- 2006