Cyclic and Event Stratification

The problem of bedding, a basic feature of most sedimenta­ ry rocks, is as old as the science of geology itself. We use bedding in structural geology, regional correlation and for estimating the time involved in the strati'9Taphic record. Nevertheless we still are far from fully under­ standing the processes involved. This is particularly true for carbonate rocks, where primary phenomena are sometimes difficult to separate from the secondary diagenetic over­ print. After new interest in the subject had arisen from the International Deep Sea Drilling Project and from pa­ leoecological studies in our own research group (Sonder­ forschungsbereich 53 "Pal6kologie"), a Rundgesprach (work­ shop) was held in Tlibingen on April 25th - 27th 1980. The present volume, which resulted from this symposium, con­ tains a variety of contributions, including some by col­ leagues that were unable to attend the meeting itself. Papers whose authors did not submit an elaborated manu­ script, are represented by abstracts in the form presented for the meeting. Our own interest in the problem envolved from studies of "Fossil-Bonanzas", such as the Solnhofen lithographic lime­ stones or the bituminous Posidonia shales, in which the unusual kind and preservation of fossils indicated extre­ me environmental conditions. During these studies (see sununary reports in Zbl. Geol. Palaont. II, 1976 and N. Jb. Geol. Palaont. , 157, 1978) we realized that even in these cases one single environmental model is usually insuffi­ cient to explain the conflicting evidences.

I. Limestone-Marl Rhythms and Climate-controlled Facies Changes.- General Remarks About the Nature, Occurrence, and Recognition of Cyclic Sequences (Periodites).- Limestone-Marl Cycles (Periodites): Diagnosis, Significance, Causes ― a Review.- Observations on Well-bedded Upper Jurassic Limestones.- Origin of Marl-Limestone Alternation (Oxford 2) in Southwest Germany.- Limestone-Shale Bedding and Perturbations of the Earth’s Orbit.- Rhythmic Sedimentation Documented in a Late Cretaceous Core (Abstract).- Ecology and Depositional Environments of Chalk-Marl and Limestone-Shale Rhythms in the Cretaceous of North America (Abstract).- Diagenetic Redistribution of Carbonate, a Process in Forming Limestone-Marl Alternations (Devonian and Carboniferous, Rheinisches Schiefergebirge, W. Germany).- A Contribution to the Origin of Limestone-Shale Sequences.- Deep-Sea Stratigraphy: Cenozoic Climate Steps and the Search for Chemo-Climatic Feedback.- IIA. Event Stratification. Calcareous and Quartz-Sandy Tempestites.- General Remarks About Event Deposits.- Experiments on the Distinction of Wave and Current Influenced Shell Accumulations.- Calcareous Tempestites: Storm-dominated Stratification in Upper Muschelkalk Limestones (Middle Trias, SW-Germany).- Allochthonous Coquinas in the Upper Muschelkalk - Caused by Storm Events? (Abstract).- The role of Storm Processes in Generating Shell Beds in Paleozoic Shelf Environments.- Rhythmic Bedding and Shell Bed Formation in the Upper Jurassic of East Greenland.- Shell Beds in the Lower Lias of South Germany ― Facies and Origin.- Storm Sedimentation in the Carboniferous Limestones Near Weston-Super-Mare (Dinantian, SW-England).- Event-Stratification in Nummulite Accumulations and in Shell Beds from the Eocene of Egypt.- The “Bank der kleinen Terebrateln” (Upper Muschelkalk, Triassic) Near Schwäbisch Hall (SW-Germany) ― a Tempestite Condensation Horizon.- Glauconitic Condensation Through High-Energy Events in the Albian Near Clars (Escragnolles, Var, SE-France).- Muschelkalk/Keuper Bone-Beds (Middle Triassic, SW-Germany) ― Storm Condensation in a Regressive Cycle.- Condensed Griotte Facies and Cephalopod Accumulations in the Upper Devonian of the Eastern Anti-Atlas, Morocco.- Distinctive Features of Sandy Tempestites.- Multidirectional Paleocurrents as Indicators of Shelf Storm Beds.- Scour and Fill: The Significance of Event Separation.- Storm-surge Sandstones and the Deposition of Interbedded Limestone: Late Precambrian, Southern Norway.- Flat Pebble Conglomerates, Storm Deposits, and the Cambrian Bottom Fauna.- IIB. Event Stratification ― Other Event Deposits.- Jurassic Bedded Cherts from the North Apennines, Italy: Dyscyclic Sedimentation in the Deep Pelagic Realm.- Quartz-sandy Allodapic Limestones as a Result of Lime Mud-Raising Clastic Turbidites.- Belemnites as Current Indicators in Shallow Marine Turbidites of the Santonian Bavnodde Grønsand, Bornholm (Denmark).- Habits of Zircon as a Tool for Precise Tephrostratigraphic Correlation.- III. Cyclicity and Event Stratification in Black Shales.- Cyclic and Dyscyclic Black Shale Formation.- Cyclicity and the Storage of Organic Matter in Middle Cretaceous Pelagic Sediments.- Types of Stratification in the Kupferschiefer.- Environmental Changes During Oil Shale Deposition as Deduced from Stable Isotope Ratios.- The Community Structure of “Shell Islands” on Oxygen Depleted Substrates in Mesozoic Dark Shales and Laminated Carbonates (Abstract).- Ammonite Shells as Habitats ― Floats or Benthic Islands? (Abstract).- Palynology of Upper Liassic Bituminous Shales (Abstract).- The Bituminous Lower Toarcian at the Truc de Balduc Near Mende (Département de la Lozère, S-France).- Bedding Types of the Toarcian Black Shales in NW-Greece.- Stratinomy of the Lower Kimmeridge Clay (Dorset, England) (Abstract).- The Formation of the Bituminous Layers of the Middle Triassic of Ticino (Switzerland) (Abstract).- Summary.- Paleogeographic Significance of Tempestites and Periodites.