local
project:
This
Local Unit will be actively involved in some of the working
groups set up to carry out the different tasks of this project:
task 1 – establishment of a high-resolution stratigraphic
framework for the late Messinian, based on a chronology of
events correlatable at a Mediterranean scale;
task 2 – timing, modes and role of tectonic activity
in the genesis of Messinian events;
task 3 - the origin of the intra-Messinian erosional surface
and associated deposits;
task 4 - timing and modes of the transition from iperhaline
to ipohaline, Lago Mare stage;
task 5 - the climatic control of high-frequency cyclical changes
in the Lago Mare depositional systems;
task 6 - time and space distribution and paleogeographic implications
of marine incursions within the Lago Mare successions;
task 7 - depositional and diagenetic history of Latest Messinian
evaporitic deposits (Upper Evaporites);
task 8 - sovra-regional synthesis of the Miocene/Pliocene
transition.
This unit will be mostly involved in the activities connected
to tasks 1, 2, 3, 5, 6 and 8, carrying out its studies in
the compressional and extensional basins of Sicily (Caltanissetta,
Corvillo and Northern Iblean basin). In these basins, a complete
revision of the stratigraphy of Messinian successions will
be carried out adopting a physical-stratigraphic approach,
with particular attention to the Upper Evaporite and Lago
Mare units. This activity will contribute to the establishment
of a regional scale, high-resolution stratigraphic framework
of latest Messinian deposits, which is the main target of
the task 1 of the research project. This activity, which will
be essentially carried out during the first year, will be
based on field work and consist on facies analysis, measurement
and sampling of selected stratigraphic sections. A particular
attention will be paid to the study of the cyclical stacking
pattern of depositional systems developed in different depositional
and structural setting, in order to recognize a possible climatic
control and to evaluate its potential for establishing a very
high-resolution stratigraphic framework. The physical-stratigraphic
analysis and the study of paleoclimatic implications, which
represent the main target of task 5, will be carried out in
collaboration with researchers of unit 6.
Much attention will be paid to the hierarchical characterization
and correlation of the unconformities occurring within the
Messinian succession (task 3 ) in both compressional and extensional
settings. An attempt to trace such erosional surfaces from
basin margins to deeper depositional settings (e.g. Eraclea
Minoa) will be performed also using subsurface data (seismic
data and ODP wells). Strictly related to this item is the
study of the largely diffused paleokarst features associated
to the intra-Messinian unconformity of the Northern Iblean
basin.
The geometric characteristics and relationships between the
different physical-stratigraphic units will help to define
in detail timing and modalities of the structural evolution
of compressional and extensional basins during the Messinian,
and their possible relationships to larger scale deformational
events (task 2).
The stratigraphic framework reconstructed during the first
phase of activity will allow to carry out the study of the
paleoenvironmental and paleoclimatic evolution of Sicilian
basin during the latest Messinian (tasks 5 and 6). A detailed
study of the palaeoenvironmental characters of the sedimentary
successions of the Upper Evaporite cycle and their fine chronological
tuning in both compressional and extensional Sicilian basins
will be performed through the integration of micropaleontological,
geochemical, magnetic and radiometric analysis. This activity
will be essentially carried out during the second year of
the project with the collaboration of researchers of units
1, 3, 6 and 7. This unit will also study in very high detail
in some selected sections the Miocene/Pliocene boundary, in
order to verify its synchronous character throughout different
morphostructural and depositional settings (task 8). For this
part of the project, that will be carried out through an integrated
biomagnetostratigraphic study of some selected sections, a
close co-operation with researchers of units 1, 3, 6 and 7
will be activated.
Along the northern margin of the Iblean Plateau a series of
detailed stratigraphic sections will be studied, which, supported
by micropalaeontological and radiometric analysis for absolute
datation will permit to recognize all possible present unconformities.
In the Iblean sector, further information will be gained from
the mapping and radiometric dating of a unit of nephelinitic
lavas that was erupted and emplaced in a wide area during
the late Messinian and thus represents an important marker
horizon. The stratigraphic data will be correlated with those
in the Caltanissetta basin in order to trace the distribution
in space of the intra-Messinian erosion surfaces in an area
that extends from the chain sector to the foreland zone.
This unit will also provide field assistance to researchers
of unit 5 for the study of the depositional and diagenetic
evolution of the Upper Evaporites (task 7) in the Sicilian
basins.
All the informations from these studies will be synthetized
in a high-detail geological map carried out following a modern
physical-stratigraphic approach.
