Skip to Main Content
Book Chapter

Alpine Front and Molasse Basin, Bavaria

By
G.H. Bachmann
G.H. Bachmann
Preussag A.G.
Search for other works by this author on:
K. Koch
K. Koch
Preussag A.G.
Search for other works by this author on:
Published:
January 01, 1983

Abstract

The foreland of the Bavarian Alps consists of the Tertiary Molasse and its Mesozoic substratum. So far 38 oil and gas fields have been found with reserves of 14 million bb1 (2.0 million MT of oil and 140 Bcf(4.0 B cu m) of natural gas (Figure 1). The fields are predominantly associated with antithetic normal faults. The lower part of the Molasse and its Mesozoic substratum dips to the south under the Alpine thrust units. The Bavarian Alps consist of four tectonic units: folded molasse, helveticum, flysch, and kalkalpin. Additional tectonic units occur to the south in Austria. The individual units are actually gigantic nappes, which were thrust upon each other from south to north.

The first section (Figures 2, 3) is located east of Munich and represents a typical part of the Molasse basin. The second section (Figures 4, 5) is located at the Alpine front east of the Iller river. Despite a distance of 100 km (62 mi) the two sections supplement each other.

Seismic exploration in the Alps and the Molasse basin is difficult because of the rough topography of the Alps, Quaternary sediments of differing thicknesses, a deep weathering zone, and heterogeneous seismic velocities in the thrust units and the Quaternary.

The top of the Variscan basement, which consists of gneisses and granites, is here only poorly defined. The basement is transgressively overlain by thin Dogger clastics and thick Malm limestone. Cretaceous (Hauterivian - Turonian) marls, limestones, and sandstone overlie transgressively the Malm and become thicker from north to south.

The most prominent reflection in the Molasse basin is at the base of the Tertiary Molasse. It can readily be correlated and mapped and is of great importance for petroleum exploration. The Cretaceous is transgressively overlain by the Molasse, which is late Eocene to Pliocene in age and consists of marls and sandstones, (i.e. the clastic debris of the rising Alps). The Molasse in eastern Bavaria is predominantly marine and brackish, and only the uppermost few hundred meters are limnofluviatile. The Molasse thickens from north to south and at the front of the orogene it is up to 5,000 m (16,400 ft) thick (Figure 1).

You do not currently have access to this article.

Figures & Tables

Contents

AAPG Studies in Geology

Seismic Expression of Structural Styles: A Picture and Work Atlas. Volume 1–The Layered Earth, Volume 2–Tectonics Of Extensional Provinces, & Volume 3–Tectonics Of Compressional Provinces

A. W. Bally
A. W. Bally
Search for other works by this author on:
American Association of Petroleum Geologists
Volume
15
ISBN electronic:
9781629810188
Publication date:
January 01, 1983

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal