IL CANYON MESSINIANO DI MALNATE (VARESE); PEDOGENESI TARDOMIOCENICA ED INGRESSIONE MARINA PLIOCENICA AL MARGINE MERIDIONALE DELLE ALPI

Abstract

The sequence exposed in a road cut near Malnate (Varese, North Italy) records Neogene paleoenvironmental changes in the Southern margin of the Alps. The "Gonfolite" Formation (Oligo—Miocene) was deeply weathered in intertropical wet environment in Late Miocene. During Messinian a deep valley has been excavated into the "Gonfolite". During the Early Pliocene transgression the valley changed to a submarine canyon in which turbidites, slump and sand flows were deposited; molluscs and foraminifera collected in these sediments provide evidence of a warm environment. At the top of the sequence glaciomarine sediments have been found; they are attributed to a Early Pliocene glacial period which is hypothetically correlated with the general climatic deterioration dating back to 3,2 Myr ago.

Keywords

• Late Miocene pedogenesis; Messinian canyon; Pliocene transgression; Tertiary glaciomarine sedimentation; Alpine Southern margin.