caa a22 4500 47706454X CHVBK 20180405111409.0 cr unu---uuuuu 170330e19960601xx s 000 0 eng 10.1007/BF02422237 doi (NATIONALLICENCE)springer-10.1007/BF02422237 Palaeogeography of radiolarite and organic-rich deposits in Mesozoic Tethys [Elektronische Daten] [P. De Wever, F. Baudin] Siliceous and marine organic-rich deposits are sometimes associated, sometimes separate in space and time; however, both are generally accepted to be the result of high planktonic productivity. Among the siliceous marine deposits, the phtanite family facies is distinguished from the radiolarite family facies by several characteristics: They contain organic material and as a result are blackish (vs red/green for radiolarite facies), their time of deposition corresponds with strong faunal modifications and they are deposited generally in shallower environments. A palaeogeographic analysis of locations of Tethyan biosiliceous and marine organic-rich rocks, both resulting from a high planktonic palaeoproductivity, for three Mesozoic high sea-level intervals, Toarcian, Kimmeridgian and Cenomanian, show: (a) during Jurassic times these Tethyan deposits were dissociated, the siliceous deposits being closer to open ocean waters than the organic-rich ones. This is a common disposition in modern upwelling systems and suggests a common process; (b) during Cretaceous times these Tethyan deposits were often associated, i.e. both occur at the same site, and are probably the result of a different process from that in the Jurassic. Springer-Verlag GmbH & Co KG, 1996 Palaeogeography nationallicence Radiolarite nationallicence Organic matter nationallicence Mesozoic nationallicence Tethys nationallicence De Wever P. Univ. PM Curie, Dept. Géologie Sédimentaire, CNRS-URA 1761, T15-16 E4, 4 Place Jussieu, F-75252, Paris Cedex 05, France aut Baudin F. Univ. PM Curie, Dept. Géologie Sédimentaire, CNRS-URA 1761, T15-16 E4, 4 Place Jussieu, F-75252, Paris Cedex 05, France aut Geologische Rundschau Springer-Verlag 85/2(1996-06-01), 310-326 0016-7835 85:2<310 1996 85 531 https://doi.org/10.1007/BF02422237 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02422237 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- De Wever P. Univ. PM Curie, Dept. Géologie Sédimentaire, CNRS-URA 1761, T15-16 E4, 4 Place Jussieu, F-75252, Paris Cedex 05, France aut NATIONALLICENCE 700 1- Baudin F. Univ. PM Curie, Dept. Géologie Sédimentaire, CNRS-URA 1761, T15-16 E4, 4 Place Jussieu, F-75252, Paris Cedex 05, France aut NATIONALLICENCE 773 0- Geologische Rundschau Springer-Verlag 85/2(1996-06-01), 310-326 0016-7835 85:2<310 1996 85 531 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer