local
project:
High-resolution
stratigraphy of the late Messinian successions
of the Tertiary Piedmont, Southern Laga and
Tyrrhenian Basins: implications for the palaeoenvironmental
and structural evolution of the central Mediterraean
area.
This
Local Unit (LU), besides the general coordination
of the Research Programme, due to the wide
range of scientific competences and available
equipment, will be actively involved in all
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.
During the first phase of the project this
Unit will be involved in the specific activities
related to task 1; as for the other tasks,
this phase will be devoted to the critical
evaluation of available data and to the collection
of new data.
Phase
1
task 1 - This Unit, together with scientific
personnel of the other LU, will carry out
the regional geologic-stratigraphic model
of the Messinian successions of the Tertiary
Piedmont Basin (TPB) and of the Southern Laga
Basin, using a physical-stratigraphic approach.
The activity will provide for the critical
revision of the available data and for the
detailed, multidisciplinary study of stratigraphic
sections cropping out in the Monferrato, Langhe
and eastern sectors of the TPB and in the
Montagna dei Fiori area ofthe Laga Basin (Vomano
valley). A particular attention will be paid
to the integration of surface and subsurface
data (wells and
seismic profiles made available by Eni-Agip);
this will allow to better evaluate the depositional
geometries of sedimentary succession and its
structural setting, in order to define the
relationships with the adjacent Padan and
Apenninic area, for which a high-resolution
stratigraphic model is already available.
The TPB and Laga Basin Messinian successions
will be completely re-examined through the
study of selected stratigraphic sections,
in order to recognize and characterize the
boundaries of the latest Messinian post-evaporitic
stage, that will be subsequently studied in
more detail for the other tasks. To this scope,
detailed biomagnetostratigraphic analysis
will be carried out on samples collected in
stratigraphic sections measured and studied
also from a sedimentologic and geochemical
point of view. This LU will also co-operate
within transversal working groups to the establishment
of similar stratigraphic models for the Tyrrhenian
sea and Tuscany basins (Volterra, Radicondoli,
Val Cecina, Tuscan archipel and eastern Sardinia
margin), and Sicilian basins (Caltanissetta,
Ciminna, Corvillo, Iblean), especially for
the physical-stratigraphic, sedimentological
and seismostratigraphic aspects. For the Tyrrhenian
and Tuscany basins an integration of surface
and subsurface data from land and marine areas
will be carried out using seismic and well
data (Agip, CNR, and ODP).
Finally, the LU will participate to the elaboration
of a stratigraphic synthesis of the latest
Messinian interval, through the comparation
of the different study areas with other Mediterranean
basins (Apennine foredeep, Ptolemais basin,
Cyprus, Sorbas, Morocco). To do that, the
study of selected field sections will be carried
out to provide an homogeneous stratigraphic
approach and to make a better integration
of data from the different basins.
Phase
2
Scientific personnel of different LU will
co-operate in specific working groups formed
to accomplish the objectives of the other
tasks. As a generalrule the activity for tasks
2-8 will start after the establishment of
the general stratigraphic framework.
task 2 - This LU will collaborate to a better
definition of the structural framework of
the central Mediterranean area during the
late Tortonian-early Pliocene, to get more
information about the tectonically-induced
topographic modifications, their amplitude
and possible role in controlling the Messinian
palaeoenvironmental changes. The efforts will
be particularly devoted to the study of the
relationships between the compressive deformations
and uplift of the Apenninic-Maghrebid chain
and the extensional regime characterizing
the Tuscan-Tyrrehnian area behind it. This
study will be carried out through the integration
of field and seismic data along specific geologic
transects. Moreover, the geodynamic relationships
between these areas will be framed within
the large-scale stress regime characterizing
the Mediterranean area during this time interval.
task 3 – This task is tightlylinked to
the previous one and concerns the the origin
of the intra-Messinian unconformity and associated
deposits through the comparation of their
characteristics in the different studied basins.
The main problem to deal with is the evaluation
of the tectonic component possibly implied
in the genesis of this erosional surface,
well recognized at the moment only in the
Apennine foredeep and probably overlooked
in the other basins.
task 4 - Selected sections from different
basins recording the transition to the non-marine
Lago Mare deposits will be studied in detail.
The activity of this LU will consist on field
work in the TPB and Tuscany basins, with the
detailed description and sampling of stratigraphic
sections, and on paleontological and geochemical
analysis (characterization of organic matter)
that will be subsequently performed by specialists
of the other LU.
tasks 5-6 - Sedimentologic, geochemical, paleontologic
and magnetic properties of the late Messinian
deposits of the studied basins will be investigated
in great detail and compared, according to
the stratigraphic framework defined in task
1. The objectives of this task are the recognition
of cyclical patterns in the lithological and
paleoenvironmental parameters , the evaluation
of their possible climatic origin, and the
definition of their periodicity through spectral
analys. This would allow to filter the local
interferences due to tectonic or intrinsic
depositional factors in order to use the cyclicity
of this interval for high-resolution correlations.
Particular
attention will be paid to verify the existence
and the episodic/vs cyclical occurrence of
marine incursions within the Lago Mare deposits.
In order to achieve these objectives, a very
detailed sedimentological, geochemical and
paleontological study is necessary. This LU
will essentially work in the TPB but will
also collaborate in the other areas. For the
achievement of the task's objectives this
LU will need to employ on shorth-term contracts(12
months) two Researchers for field studies
and laboratory analysis.
For task 7 this Unit will make the laboratories
of the Department available for all the necessary
analysis.
For task 8, whose main aim is to verify the
exact timing and characteristics of the transition
from Lago Mare to fully marine conditions
and its variability according to the local
and regional morphostructural settings, personnel
of this Unit will study the Mio/Pliocene boundary
in the TPB; a critical revision of data from
other Mediterranean areas for which a large
volume of data are available (ODP wells, Apennine
foredeep) will be also carried out. The activity
implies the micropaleontological study of
samples from field section or from short cores;
on the latter, Gamma Ray and Magnetic Susceptibility
logs will be performed (at Agip and CNR laboratories)
to recognize cyclical patterns that could
be eventually tuned against astronomical curves
of solar irradiance to improve the stratigraphic
resolution of basal Pliocene deposits.
