Abstract
The limestones of the Cretaceous-Paleocene “Red Beds” in the Alpine ranges are biomicrites. Their micrite is chiefly made up of whole or broken-up coccoliths, also of fragments of foraminifers. The lithification of the limestones is a phenomenon of electrodiagenesis. The iron oxides are authigenetic; they were incorporated with the rock during the different phases of its evolution (early and late diagenesis and premetamorphic phase). At the beginning, the iron was extracted by halmyrolysis from a biomass reduced to the mineral state after the death of the organisms. Montmorillonite constitutes the chief element of the argillaceous minearals. The geochemical conditions of the environment of the “Red Beds” are quite different from those of present-day deep-sea Globigerina ooze to which we might to be tempted to liken them. At the present state of research an environment identical to that where “Red Beds” were formed is not known. A number of geological and petrographic characteristics let us suppose, however, that this environment was not deep.
Published Version
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