3. PALEOENVIRONMENTAL SIGNIFICANCE OF CENOZOIC CLAY DEPOSITS FROM THE NORWEGIAN SEA: ODP LEG 1041

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Norwegian Sea; Rockall Plateau; Iceland; North Atlantic; Northeast Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.555.3202; http://www-odp.tamu.edu/publications/104_SR/VOLUME/CHAPTERS/sr104_03.pdf

The mineralogical and geochemical study of samples from Sites 642, 643, and 644 enabled us to reconstruct several aspects of the Cenozoic paleoenvironmental evolution (namely volcanism, climate, hydrology) south of the Norwegian Sea and correlate it with evolution trends in the northeast Atlantic. Weathering products of early Paleogene volcanic material at Rockall Plateau, over the Faeroe-Iceland Ridge and the Vdring Plateau indicate a hot and moist climate (la-teritic environment) existed then. From Eocene to Oligocene, mineralogical assemblages of terrigenous sediments sug-gest the existence of a warm but somewhat less moist climate at that time than during the early Paleogene. At the begin-ning of early Miocene, climatic conditions were warm and damp. The large amounts of amorphous silica in Miocene sediment could indicate an important flux of silica from the continent then, or suggest the formation of upwelling. Up-permost lower Miocene and middle to upper Miocene clay assemblages suggest progressive cooling of the climate from warm to temperate at that time. At the end of early Miocene, hydrological exchanges between the North Atlantic and the Norwegian Sea became intense and gave rise to an important change in the mineralogy of deposits. From Pliocene to Pleistocene, the variable mineralogy of deposits reflects alternating glacial/interglacial climatic episodes, a phenome-non observed throughout the North Atlantic.