RICERCA ITALIANA     

Tectono-magmatic evolution of Campi Flegrei - Southern Italy

Università degli Studi del Sannio di Benevento

Abstract

The analysis of the previous research work on Campi Flegrei documents that intense volcanism and volcano-tectonic deformations occurred during Late Quaternary and that they are still active. However, different opinions were exposed about: dimensions and timing of calderas; magma evolution, resurgence mechanisms; role played by regional fault systems. The main purpose of this project is to disclose the tectono-magmatic evolution of Campi Flegrei by studing the general structure and geomorphology of the volcanic field, togheter with the geochemical trends of the volcanic products. At the same time, the research program will be aimed to define the geochemical parameters which control the internal magmatic dynamics of the active volcanoes. Potential obtainable results are: 1) geobarometric, thermometric and compositional determination of melts and co-existing volatile phases; 2) the influence of volatiles on the equilibrium phase of Campi Flegrei alkaline magmas.
A morpho-structural study will be performed. A detailed mapping of the volcano-tectonic and tectonic landforms represented in the area by mouth alignments, fault scarps, tectonic depressions, etc., or deductibles from anomalous positions of different landforms like ancient coast-lines and terraced surfaces, subsequent streams and correlative hydrographic anomalies, etc. will be made. The study of lineaments and faults will follow three steps : data acquisition, statistical analysis of linear forms and geological >>>

Principal Investigator

Agostino ZUPPETTA Università degli Studi del SANNIO di BENEVENTO

Research Objectives

The research program, whose final goal is to develop a coherent tectono-magmatic model for the evolution of the Campi Flegrei Volcanic Field, is splitted in two main areas: a morpho-tectonic area and a geochemical one.
The main goal of the structural part of the program is to establish the regional fracture patterns in the area of interest and if a relationships between the recognized fault systems, the onset and the volcanic evolution exist.
We will construct a geomorphological map, an air-photo lineament map, a Landsat lineament map and finally a field fault map.
We will also characterize the tectonic environment by calculating from the previous data the orientations of the principal stress axes in order to be able later to couple this information with the areal distribution of the volcanic products.
At the same time, the geochemical studies will be focused on the melt inclusions and will be aimed to define the parameters which control the internal magmatic dynamics of the active volcanoes. Potential obtainable results are:
1) geobarometric, thermometric and compositional determination of melts and co-existing volatile phases;
2) the influence of volatiles on the equilibrium phase of Campi Flegrei alkaline magmas.
The study of products with different chemical and mineralogical composition, such as those characterized by different eruptive mechanisms, are aimed to understand if differences in chemical and physical >>>

Timescale

24 months

National and international background

The Campanian Plain and Campi Flegrei represent structural depressions of the Campanian Apennine, a thrust belt developed during the continental collision after the closure of the Ligure Ocean.
The deformation which started in Langhian time was active since Upper Pliocene - Lower Pleistocene, when the Apenninic thrust belt override the foreland sediments. During the Upper Pliocene, the inner part of the chain started to uplift and, as a consequence of the still active sinking of the Adriatic-Ionian plate in the outer sector of the chain (Foredeep Bradanico), a new marginal inner basin started to develop (Tyrrhenian Basin).
Accordino to Turco & Zuppetta (1998) the sinking is also responsible for the genesis of arc structures in the Apenninic chain (p.e. Calabrian arc). A synthesis of the available geological and geophysical data leads
the authors to suggest, in contrast to the classical Horst and Graben extension structures proposed by the previous researchers, that the progressive migration of the Apenninic Arcs is responsible for the extension phenomena which took place during the last 5 Ma. At first, the extension resulted from the kinematic interaction between the Northern Apenninic Arc and the Southern Apenninic Arc during the Late Pliocene. Then, from the Early Pleistocene the extension was controlled by the SE migration of the Southern arc only, and therefore it can be regarded as part of the general Southern Tyrrhenian extension phenomenon. Due to >>>