Mid-Pliocene sediments from Ocean Drilling Program Hole 964A (Ionian
Basin) and from Punta Piccola outcrop (Sicily, Italy) consist of
light-colored carbonate-rich marls (decimeter to meter thick) alternating
with dark-colored, carbonate-poor, organic matter–rich beds
(1–25 cm thick). These sediments show cyclic variations in their
mineralogical content, especially in the clay mineral relative percentages.
Palygorskite and kaolinite are abundant in carbonated intervals,
whereas smectite and chlorite dominate in dark ones. As palygorskite
is known to originate from Africa, through wind transportation, we
interpret these cyclic variations to be a result of the alternation
of dry periods, with dominant eolian sedimentary input from the south,
and humid periods, with dominant fluvial supply.
complet (voir l'article 18 du volume sur le site Internet d'ODP)