local
project:
The
Research Programme of this local Unit will regard
a multidisciplinary study of sedimentary successions
of Messinian- Lower Pliocene ages.This Unit 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 tectonics
in the genesis of the 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 conditions, 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 evaporiticdeposits (Upper
Evaporites);
task 8 – sovra-regional synthesis of the
Miocene/Pliocene transition.
The main activity will consist of a critical revision
of available data of a detailed study of significant
Messinian sections cropping out in the Volterra-Radicondoli-Chiusdino
and Bacino dell’Elsa-Siena p.p. basins, and
will provide a analythical basis for a regional-stratigraphic
model (task 1). The research will develop through
geological, biostratigraphic, paleoclimatic, sedimentologic
data. The programme will focus on geological-sedimentological
and quali-quantitative analysis of the micropaleontological
associations (Foraminifera, Ostracoda and nannofossils)
to define:
a) the development of Lago-Mare deposits and their
relationships with others litofacies; b) the transition
from iperhaline to ipohaline (Lago-Mare stage)
conditions (task 4); c) the Lago-Mare facies and
the occurrence of marine incursions (task 6),
d )the characteristics of the transition from
Lago-Mare to fully marine conditions at Miocene-Pliocene
boundary (task 8), e) the climatic and tectonic
influences on the sedimentary successions. This
study will be carried out through the integration
of field and seismic or core data toward an improved
definition of the depositional structure of messinian
successions. The collaboration with Unit 4 will
aim to the reconstruction of a geological-stratigraphical
model of Tuscan and Tyrrehnian area (task 1).
Scientific personnel of Unit 6 will co-operate
to stratigraphic-physical studies about the Lago-Mare
successions, to comparison to the high resolution
geological-stratigraphic model of the padan and
appeninic area. This Unit will co-operate to others
to define a framework of tectonic-sedimentary
evolution of a Tyrrhenian-adriatic area, in the
late Tortonian- Lower Pliocene interval. The efforts
will be mainly devoted to the study of the relationships
between the compressive deformations and the extensionalregime
characterizing the Tuscan-Tyrrhenian area. This
study will be carried out through the integration
of field and seismic data along specific geologic
transects.
For what concerns the genesis of the intra-messinian
surface (task 3), the deposits associated to the
unconformity known in the Tuscan successions will
be investigated.
On the other hand, as regard to the climatic influence
on the Lago-Mare successions during the latest
Messinian in the Tyrrhenic area, the signal could
be found in the terrigenous deposits. It appears
important to correlate the climatic curves to
isotopic oxygen curves made through planktonic
Foraminifera in the oceanic areas.In order to
reach this goal, some studied atlantic successions
of Marocco appear significant. To achieve a better
result the Tuscan successions may be correlated
to high resolution astronomic curves (task 5).
Field work and laboratory analyses will be partially
carried out by short-term contracts Researchers
.
