Author: Riccardo Cestari & Dario Sartorio
Language: English
1995; Hardcover;250x305mm;207

Table of Contents

Rudists are fossil bivalves that lived on the margins of the Tethyan Ocean and adjacent areas from the end of the Jurassic until the end of the Cretaceous. These sessile benthic organisms flourished in carbonate platform environments and characterize several Cretaceous successions as significant organic builders and sediment producers.This makes it possible to correlate different paleogeographic domains from the Gulf of Mexico to the Middle East. The aim of this atlas is to examine in detail the particular role that Rudist facies played in the development and history of Cretaceous carbonate platforms of the Periadriatic Domain. In this area, which in a paleogeographical sense belongs to the Apulian Plate, many Mesozoic carbonate platform successions crop out. These successions belong to broad platform complexes which display a pattern aligned with the present-day 1sea. In these limestones, various Rudist facies are present, often making it possible to date and to correlate successions encountered by wells with those observable in outcrops. For this reason, we though it would be useful to assemble and to illustrate the ample documentations that has been acquired over the years so as to update the situation as regards Rudists and the related facies in the this area. This present volume has been conceived as and aid to all those who are working on these topics by taking different approaches including sequence stratigraphy, which is considered to be an important methodology for analyzing the evolution of carbonate platforms. Another objective of our work is to better define the Rudist-bearing Periadriatic successions and to compare them with those of other Tethyan Domains that developed in different tectono-sedimentary settings.

The first chapter of the atlas illustrates the evolution of the main Rudist families as well as those features useful for theiri dentification and taxonomic determination, both in outcrop and core analysis. To simplify the presentation of their characteristics, in view of the difficulty of isolating complete specimens of Rudists from the mainly massive limestones of the Periadriatic Domain, some specimens collected from other regions have also been illustrated. Genera with particular stratigraphic significance for this Domain are also briefly discussed. This chapter closes with an illustration of the stratigraphic distribution of the most significant Rudists of the Periadriatic area.

The next chapter, regarding Rudist sediments and their depositional environments, also introduces a classification of Rudist facies that can be applied both to outcrop and sub-surface and which can be easily utilized in oil exploration.

The third chapter illustrates the most important Rudist assemblages of the Periadriatic Domain in time. SeventeenRudist events (from Event A to Event Q) have been identified in stratigraphic succession, taking into account macro-and micropaleontological assemblages and correlations with other areas (France, Spain, North Africa, Middle East and others) where the same, or similar, facies comprise important paleontological markers such as the ammonites and planktonic forams. In this chapter several Rudist facies, mainly of outcrops, are shown in considerable detail in thin and polished sections and often with their micropaleontological assemblages.

The final chapter concerns the role played by these mollusks in oil and gas exploration. In fact, their shells and the bioclasts that derive there from often improve the petrophysical features of the rocks that characterize many oil and gas reservoirs, including those of the Periadriatic Domain.