Upper Jurassic

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system series step ≈ age ( mya )
higher higher higher younger
law Upper Jurassic Tithonium 145
⬍
152.1
Kimmeridgium 152.1
⬍
157.3
Oxfordium 157.3
⬍
163.5
Middle Jurassic Callovium 163.5
⬍
166.1
Bathonium 166.1
⬍
168.3
Bajocium 168.3
⬍
170.3
Aalenium 170.3
⬍
174.1
Lower Jurassic Toarcium 174.1
⬍
182.7
Pliensbachium 182.7
⬍
190.8
Sinemurium 190.8
⬍
199.3
Hettangium 199.3
⬍
201.3
deeper deeper deeper older

The Upper Jura (also Upper Jura ) is the top chronostratigraphic series of the Jura in geological history . In the older literature, e.g. Sometimes also in popular scientific literature, this section is often referred to as Malm or Weißer Jura (Weißjura). However, both terms should no longer be used for the chronostratigraphic unit. However, they are still used within the framework of the lithostratigraphic structure of the South German and North German Jura (in the sense of a group of formations ). The Upper Jurassic lies on the series of the Middle Jurassic and is overlaid by the Berriasium of the Lower Cretaceous series. In the geochronological classification it corresponds to the period from about 163.5 to 145 million years.

Older names

In older works, but especially in popular scientific literature, this period is also referred to as the Weißer Jura (Weißjura) or Malm. This is not correct, as two different stratigraphic structures (chronostratigraphy and lithostratigraphy) are mixed up here. The lithostratigraphic unit of the White Jura or Weßjura in southern Germany is primarily dominated by light limestone and limestone marl, hence the name. However, since the deposits of the White Jura set in well after the beginning of the Upper Jura and in large areas of the South German Jura stop well before the Jura / Cretaceous border, the lithostratigraphic term White Jura is not exactly synonymous with the chronostratigraphic Upper Jura series. Malm is another historical term that is still used frequently for the Upper Jura series. The name comes from rocks that come to light in the vicinity of Oxford in England. Today it is provisionally reserved for a lithostratigraphic group in the Upper Jura of northern Germany (North German Malm). There is a problem with the scientific dating of the most recent deposits. The so-called Münder Formation was previously placed as the uppermost (youngest) lithostratigraphic formation in the Malm, but according to the biostratigraphic correlation (comparative fossil content) the Jurassic-Cretaceous boundary is already within the Münder Formation. A final decision has not yet been made about the ultimate demarcation and use of the stratigraphic unit of North German Malm in central and northern Germany.

Chronostratigraphic subdivision of the Upper Jurassic series

The chronostratigraphic Upper Jurassic series is further divided into the following stages:

distribution

Tiersteinfels on the Swabian Alb near Bad Ditzenbach

The Upper Jura is largely open in southern Germany ( Swabian Alb and Franconian Alb ), the French Jura and Switzerland. In addition, the Upper Jura also comes to light in northern Germany in the Weserbergland and Leinebergland .

Fossil Sites and Economic Importance

Quarry in Solnhofen limestone. Langenaltheim , Franconia

It is limestone with fossil-bearing horizons switched on. Famous limestones of the White Jura are the very fine-grained limestones of Solnhofen and environment of Alois Senefelder in 1798 for the lithography , the lithography was discovered. The discovery of the first and subsequent specimens of Archeopteryx in the Solnhofen limestone limestone is of outstanding importance for paleontology . In addition to the Solnhofen limestone, the Treuchtlinger marble, a limestone rich in fossils such as ammonites , belemnites , brachiopods , sea urchins and mussels, is known nationwide. It is processed into wall and floor panels for architectural purposes. In southern Germany, the Upper Jura is an important karst aquifer . It is also used to generate geothermal energy in the area of ​​the Molasse Basin .

Individual evidence

  1. ↑ Eckhard Mönnig: The Jura of Northern Germany in the Stratigraphic Table of Germany 2002. Newsletters on Stratigraphy, 41 (1-3): 253-261, Stuttgart 2005

literature

  • Friedrich August Quenstedt: The Jura. Laupp Publishing House, Tübingen 1856–57.
  • Gert Bloos, Gerd Dietl & Günter Schweigert: The Jura of Southern Germany in the Stratigraphic Table of Germany 2002. Newsletters on Stratigraphy, 41 (1-3): 263-277, Stuttgart 2005 ISSN  0078-0421
  • Felix Gradstein, Jim Ogg, Jim & Alan Smith: A Geologic timescale. Cambridge University Press 2005 ISBN 9780521786737
  • Eckhard Mönnig: The Jura of Northern Germany in the Stratigraphic Table of Germany 2002. Newsletters on Stratigraphy, 41 (1-3): 253-261, Stuttgart 2005 ISSN  0078-0421

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