APPALACHIAN STATE UNIVERSITY ITALY FIELD CAMP: FROM SHORTENING THROUGH EXTENSION ACROSS A COMPLETE TECTONIC SYSTEM

The Appalachian State University international field course in Italy is designed to provide an integrated tectonic perspective of an orogenic system. The Triassic-Recent geologic evolution of the Northern Apennines consists of two major tectonic events that are remarkably well preserved in the stratigraphy and exposed structures. The first tectonic phase occurred during Jurassic time and consisted of widespread upper crustal extension, which formed a horst-and-graben sequence recorded in syn- and post-extensional sedimentary rocks. The modern architecture of the Apenninic chain is the consequence of Oligocene-present subduction and rollback of the Adria microplate beneath the Italian peninsula. This rollback system is marked by closely coupled foreland shortening and hinterland extension: material is accreted in the foreland along thrust faults, and is extruded in the hinterland along normal faults.

The ASU field program is arranged into three main projects that track material passing through the orogenic wedge from foreland to hinterland. The individual projects are designed to build upon both an evolving skill set, as well as contextual knowledge. The first project takes place in the foreland fold and thrust belt and focuses on defining the Mesozoic-Cenozoic stratigraphy and youngest foreland shortening structures. The second project involves mapping the same stratigraphy along the foreland-hinterland transition where extension in the upper crust in the form of high angle normal faults has cut older inactive thrust faults. The third and final mapping project takes place along the margin of a hinterland metamorphic core-complex; here extensional faulting has cut into the middle crust exposing rocks that have passed through the deepest part of the wedge. These greenschist facies rocks are the exact metamorphic equivalents of the stratigraphy from the first two projects, and preserve mappable shortening and extension related structures and fabrics acquired during tectonic burial and exhumation respectively.