National Research Project - GEO03
PRINCIPAL INVESTIGATOR: Carlo DOGLIONI
TITLE: The journey of the continental lithosphere: consequences on orogens and climate (Progetto sottomesso a valutazione)
FUNDING AGENCY: Ministero Università e Ricerca
START DATE: novembre 2021
END DATE: marzo 2023
ABSTRACT:
Plate tectonics theory is the biggest revolution in Earth Sciences able to explain many geological features and processes on Earth. Anyway, some main issues are still debated, or their mechanisms are still unexplained.
Among these, the subduction of continental lithosphere and the factors controlling the exhumation of large volumes of continental crust, when collision is still active, need further investigation.
The processes involved in the building of an orogenic belt and its destruction deserve an interdisciplinary approach including structural geology and tectonics, magmatism, metamorphism, geophysics, and geochemistry (e.g., production and escape of fluids among which green-house gases such as CO2). The evolution of an orogenic belt affects many aspects of human life with the localization of areas of relevant natural hazard or distribution of raw materials. The Apennine-Alpine-Himalayan and Carpathian orogenic system represents an exceptional natural laboratory including both West- and East-directed subduction settings, small orogens like
the Alps and wide orogens such as the Himalayas, where it is possible to investigate the fate of an orogen.
The aim of the project is to study the mechanisms allowing the formation, evolution and consumption of different types of orogens with the aim to understand: (i) why the continental lithosphere can subduct; (ii) the interplay and feedback relationships between tectonics and metamorphism during the evolution of an orogen and its consequences on fluids circulation; (iii) how uplift and surface processes affect the climate; (iv) how to properlyì model the climatic effects of continental subduction; (v) what is the seismological signature of this evolution; (vi) which are the constraints determining seismicity.
The study areas are specific sectors of the Alps, Apennines and Himalayas and the main targets are:
- - analysis and modeling of the subduction and exhumation of continental crustal slices;
- - tectonic, metamorphic and magmatic evolution during the subduction process;
- - reconstruction of the evolution of mega- shear zones affecting the metamorphic behavior of collisional orogens;
- - reconstruction of the timing and duration of tectono-metamorphic processes;
- - reconstruction of the geometry, depth and behavior of the decollements of the orogens;
- - construction of new updated tomographic sections in the Alpine-Himalayan belt;
- - quantification of uplift and subsidence rates in the orogen and foreland basin, respectively;
- - reconstruction of orogenic evolution through time from the sedimentary record;
- - computation of the energy balance of the continental subduction and collision;
- - modeling of different types of dissipation by ductile deformation and earthquakes.
The integration of the results will allow to move forward into the comprehension of plate tectonics and its relations with natural hazards and global changes that we must face