Detrital (U-Th)/He Thermochronometry in the Hanging Wall Basin of the Paros Metamorphic Core Complex, Central Aegean, Greece

Evan Bargnesi
University of Kansas Department of Geology Lawrence, KS
[email protected]

Large-scale, back-arc extension in the Central Aegean has facilitated the exhumation of metamorphic core complexes via detachment faulting. The Cycladic Islands generally expose the metamorphic footwall units, but the sedimentary hanging wall is largely underrepresented. The island of Paros records a nearly complete succession of these upper-plate sediments, which were originally interpreted as foreland basin deposits, but subsequently reinterpreted as a syn-extensional supradetachment basin. The basin fill, however, most likely records a more complicated tectonic and depositional history as it can be subdivided into a folded, lower turbidite sequence containing Mesozoic limestone olistoliths near its base and a massive conglomeratic upper sequence characterized by lower-plate detritus. This study seeks to resolve the depositional environment, depositional age, detrital provenance, and tectonic and thermal evolution of the hanging wall basin through detrital (U-Th)/He thermochronometry. A detailed provenance study of hanging wall sediments will reveal the relative sources to the basin and their respective thermal histories obtained from (U-Th)/He thermochronometry. These data will allow a comprehensive tectonic reconstruction of heating and cooling events in the source area. This study will perform thermochronometry on the footwall units to evaluate them as a potential source to the hanging wall basin and will also provide contextual evidence for local thermal activity. By utilizing zircon, apatite, monazite, rutile and magnetite this study will provide a comprehensive thermal history of the basin sources between ~300°C to ~60°C in order to elucidate the provenance and thermal evolution of the sedimentary packages in the upper-plate of the Paros core complex.

AAPG Search and Discovery Article #90094 © 2009 AAPG Foundation Grants in Aid