The Cenozoic evolution of the Giudicarie fault system (eastern/southern Alps, northern Italy) : : a geochronological, structural and paleomagnetic study / by Hannah Pomella

• VerfasserIn: Pomella, Hannah
• Place / Publishing House: 2010
• Year of Publication: 2010
• Language: English
• Classification: 38.55 - Regionale Geologie; 38.17 - Geochronologie; 38.71 - Geomagnetik. Geoelektrik. Geothermie
• Physical Description: 150 S.; Ill., graph. Darst., Kt.
• Notes: Zsfassung in dt. Sprache

ger: The Periadriatic line is one of the longest and most outstanding fault systems in the Alps, extending for some 700 km from north-western Italy to Slovenia. This thesis focuses on the NE-SW-trending central segment of the Periadriatic line, namely the Giudicarie fault system (GFS), which can be subdivided into: (1) the Southern Giudicarie fault, (2) the Northern Giudicarie fault (i.e. the Giudicarie Line s.s.), and (3) the Meran-Mauls fault. In spite of numerous studies on the Periadriatic line during the last 100 years, the role of the Giudicarie fault system is still controversial. The first part of the study concentrates on the Periadriatic intrusions, termed "tonalitic lamellae", which crop out along the Giudicarie fault system. In the second part, the units forming the foot- and hanging wall of the Giudicarie fault system are analysed with respect to their structural evolution and time-temperature history.<br />Based on the data provided by this thesis a 3-step evolution model is proposed for the Giudicarie fault system. In the Oligocene the tonalites intruded as part of the NE Adamello batholith, bordered to the north by an originally straight, dextral strike-slip fault, i.e. the Periadriatic line. At the Oligocene/Miocene boundary the NNW-wards movement of the Southalpine indenter led to a bending of the fault and material from the northeastern part of the Adamello batholith was squeezed towards the NE along the newly bent part of the fault.<br />In the Early Miocene the brittle Passeier fault, together with the Northern- and Southern Giudicarie faults, finally dissected the bent part of the Periadriatic line. Along the northern part of the bend (Meran-Mauls fault) a nearly continuous tonalitic body is still present, whilst along the Northern Giudicarie fault only small boudinaged bodies are preserved.<br />Six geological cross sections have been constructed depicting the Giudicarie fault system together with additional and partly related/reactivated faults in its nearer foot- and hanging wall. Fission track data are projected onto these profile lines and assist the interpretation. The strong similarities between the units exposed to the NW of the Northern Giudicarie fault and the Meran-Mauls fault argue for a coherent Cretaceous to Tertiary evolution. The resulting differences are therefore only due to the Miocene indentation of the Southern Alps.<br />