The Colle Curti Mammal Site in the Colfiorito area Umbria-Marchean Apennine, Italy): geomorphology, stratigraphy, paleomagnetism and palynology

An approximately90 mthicksequencehasbeenstudiedinthe ColleCurtibasin(Colfioritoarea,Umbria-MarcheanApennine).Itwasdepositedin adrainagesystemcharacterizedbya‘mature’landscapewithouta clearwatershedseparatingtheAdriaticandTyrrheniansides.Closetotheendof the Early Pleistocene this landscape was dismembered by the activation of extensional faults, linked to an uplifting of the chain that reached its greatest magnitude at the beginning of the Middle Pleistocene. From a sedimentological point of view the sequence can be roughly divided into threeparts,withgraveldepositionin abraidplainenvironmentdominatingthelowerandupperparts,and aphaseof claydepositionina lacustrine environmentseparatingthese.AnAr/Aranalysisonthesanidinecontainedinavertisolintheupperpartofthesequencegaveanagenotolderthan 427 ka. An early Galerian fauna was collected in clay layers where the Jaramillo palaeomagnetic event was recognized. Cold periods are documented in the lower and upper part of the sequence, although in the latter the intense weathering caused by the development of a soil with tropical features precludes further investigations. The palynological data supported by sedimentological and palaeomagnetic evidence indicate that the sequence can be related to a large part of the Bavelian and part of the Menapian. In the middle part, where clay layers outcrop, two cool and humid phases are followed by colder and drier periods. Biological and geological evidence suggests that around 1My the basin of Colle Curti was probably located at an elevation of about 600 m.