ABSTRACT Final closure of the Neotethys Ocean basin along the Eurasian margin in southeastern Europe during Eocene–Oligocene time was accompanied by upper-crustal extension expressed as a series of low-angle detachments, basins bounded by normal faults, and volcanism. This extensional belt spanned the southern Balkan Peninsula from the Albanides along the southern Adriatic coast in the west to western Anatolia in the east. Despite the widespread occurrence of this phenomenon within the southern Balkan region, similar extension has not previously been observed in association with the Neotethys closure in the Dinarides, which form the western geographic continuation of this orogenic belt, ending in the Austrian Alps in the northwest. The Mid- Bosnian Schist Mountains are a fault-bounded body of greenschist-facies metamorphic rocks located along the paleogeographic margin of the present-day Adria continental block in the Internal Dinarides. We combine low-temperature thermochronometric ages with field observations of kinematic shear sense indicators and demonstrate that the Mid- Bosnian Schist Mountains were exhumed along a normal fault between 43 and 27.5 Ma. The most rapid cooling occurred between ca. 35 and 27 Ma, coincident with a regional-scale magmatic event. These data constitute the first evidence for major extension in the Dinarides contemporaneous with collision between Adria and the Eurasian margin, and they are consistent with removal of a subducting slab during the transition between oceanic subduction and continental collision.

The Mesozoic and Paleogene pelagic carbonate rocks of the Northern Apennines have proved to be a fertile source for paleomagnetic research. Investigations of the magnetic properties of the Scaglia limestones illuminated the processes by which they were magnetized. Their directions of remanent magnetization contributed to an understanding of the geodynamic history of Adria as a promontory of the African plate and have been used to refine the Mesozoic part of the African polar wander path. Magnetic stratigraphy in the Umbrian sequence and in similar facies in the southern Alps has established an independent record of geomagnetic polarity history since the Middle Jurassic. Correlation with the record derived from interpretation of oceanic magnetic anomalies mutually confirmed the global nature of the polarity history. This enabled the dating of plate motions and the development of a geomagnetic polarity time scale for the late Mesozoic and Cenozoic.