PLEISTOCENE DEFORMATION OF THE COLLINA DI TORINO INFERRED FROM THE MODELLING OF THEIR FLUVIAL SUCCESSION

Abstract

Boano P., Forno G., Lucchesi S., Pleistocene deformation of the Collina di Torino inferred from the modelling of their fluvial succession. (IT ISSN 0394-3356, 2004).
The modelling of the Po plain adjoining the Collina di Torino by Alpine watercourses, now tributaries of the Po, is evidence of the
extremely recent setting of the present River Po. Suspended traces of an earlier collector have been preserved on the Western and
North-Western slopes of the Collina di Torino, where remains of a terraced succession of surfaces with local fluvial deposits can be
find out along the present watersheds. Differentiation and correlation of the individual surfaces according to their elevation and the
alteration degree of their sediments has provided a chronological record of the Middle Pleistocene-Holocene.
This succession is the result of the progressive deformation of the distal sectors of the Alpine fans involved in the uplift of the Collina
di Torino, which has resulted in deep erosion of the ancient hydrographic pattern as shown by the scarps tens of metres high between
the surfaces. It may be supposed that the progressive uplift of the relief and the NW migration of their outer edge brought initially flat
areas into the relief and led to a differential deformation of ancient relief forms and deposits of different ages. Comparison between
the chronology of these surfaces and their distribution within an approximately 400-metres difference of level shows that the rate of
uplift from the Middle Pleistocene to the Holocene was of the order of 1mm/yr.