Fossils from the Polish Bathonian clays

Dr Michał Zatoń (Poland) The Middle Jurassic Bathonian stage, which is preceded by Aalenian and Bajocian and overlaid by the Callovian, was established on the basis of oolitic limestones outcropping at Bath in Somerset. This historical and English connection is a major reason I have chosen the Bathonian as a topic for Deposits Magazine. The Bathonian clays in Poland, like the English classic Kimmeridge Clay or Callovian Oxford Clay, are characterised by their rich fossil content. Although some years ago, the Bathonian clays from Poland were not as well known as these two English formations, today they have become progressively more recognised outside of Poland. This is due to an increasing number of publications dealing with different aspects of the clays and the 7th Jurassic Congress held in Kraków (southern Poland) in 2006, during which scientists from all over the world had the chance to meet and actually look at the Bathonian clays. Geological and palaeogeographical background The best outcrops of Bathonian clays are in southern and south-central Poland, in an area called the Kraków-Częstochowa Upland (Fig. 1). Here, the Jurassic rocks, and especially Oxfordian (Upper Jurassic) limestones, form a distinct belt stretching approximately in a south-east to north-west direction. That is why the late Professor Stefan Zbigniew Różycki in 1960, when comparing the area with such classic areas as the Swabian and Franconian Jurassic, called it the ‘Polish Jura’. Fig. 1. A map of Poland without the Cenozoic cover: 1. Pre-Jurassic, 2. Jurassic, 3. Cretaceous; PJ – Polish Jura. … Read More

To access this post, you must purchase Annual subscription, 12 Month Subscription or Monthly subscription.
%d bloggers like this: