Step-wise extinctions at the Cretaceous-Tertiary boundary and their climatic implications

A comparative study of planktonic foraminifera and radiolarian assemblages from the Cretaceous-Tertiary (K-T) boundary section of the Beloc Formation in the southern Peninsula of Haiti, and the lowermost Danian sequence of the Micara Formation in southern Cuba reveals a remarkable pattern of step-wise extinctions. This pattern is consistent in both places despite the widely different lithologies of the two formations. Because of a step-wise extinction and the delayed disappearance of taxa known to be more representative of cooler water realms, it is inferred that a cooling trend which characterized the close of the Maastrichtian and the onset of the Tertiary had the major adverse effect on the existing biota. Although repetitive lithologic and faunal fluctuations throughout the Maastrichtian sediments found at Deep Sea Drilling Project (DSDP) site 146/149 in the Caribbean Sea indicate variations reminiscent of known climatically induced cycles in the Cenozoic, rapid biotic succession appears to have taken place during a crisis period of a duration greater than 2 mission years. Widespread and abundant volcanic activities recorded in the Caribbean area during the crisis period gives further credence to earlier contention that intense volcanism may have played a major role in exhacerbating pre-existing climatic conditions during that time

Utilisation de l'herbe hydroponique en alimentation animale

— Les constatations suivantes d’ordre zootechnique et d’ordre économique paraissent résulter de l’utilisation de cette méthode : a) sécurité dans l’élevage des jeunes résultant de la mise en état maximum de l’organisme maternel, du barrage aux maladies du tractus génital et particulièrement de l’infection brucellique (cf. le Professeur Moussu, qui préconisait déjà en 1927 et 1928 l’appli cation d’huile de germes de blé dans le traitement des avortements), du développement de la solidité du fœtus à la naissance ; b) gain dans l’évolution de croissance du sujet au long de sa vie ; c) maintien de la production laitière qui augmente en quantité et en qualité ; d) économie dans l’alimentation qui permet de réduire les compléments d’appoint