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Wilson, C. K.
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- PublicationOpen AccessIllumination of the Crustal Structure in the Southern Apennines using Teleseismic Receiver Functions, CAT/SCAN Project(2006)
; ; ; ; ; ; ; ;Steckler, M. S.; Lamont-Doherty Earth Observatory of Columbia University ;Wilson, C. K.; Lamont-Doherty Earth Observatory of Columbia University ;Piana Agostinetti, N.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Roselli, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Seeber, L.; Lamont-Doherty Earth Observatory of Columbia University ;Amato, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Lerner-Lam, A.; Lamont-Doherty Earth Observatory of Columbia University; ; ; ; ; ; Field geology, well data and seismic imaging have illuminated the upper crustal structure of the Southern Apennines. However, lack of control of the deep structure allows viable competing thin-skin and thick-skin models of the orogen. In thin-skin models the detachment decouples a stack of rootless nappes from the basement. In thick-skin models, basement is involved in the most recent phase of thrusting. To examine the deep crustal structure, we use the teleseismic recordings from the CAT/SCAN array, deployed in southern Italy from Dec. 2003-Oct. 2005. We use receiver functions processed into a Common Conversion Point stack to generate images of the crust. We image three main westward-dipping seismic-velocity discontinuities where P-to-S conversions occur. They correspond to velocity jumps at the Moho, the upper-lower crust boundary and sedimentary interfaces resulting from the contrast between clastic and carbonate strata with basement. The CCP image matches features from both thin-skin and thick skin model. The lateral continuity of the converters favors thin skin, but consistent interpretation across the image favors the thick skin. Overall, the results provide a better fit to the thick-skin interpretation. This suggests a change in structural style as the collision with Apulia halted motion. This model also implies considerably less Plio-Pleistocene shortening across the Apennines and a SE motion of the Calabrian Arc subparallel to the southern Apennines rather than a radial expansion of the Arc.177 78 - PublicationRestrictedCrustal structure in the Southern Apennines from teleseismic receiver functions(2008-02)
; ; ; ; ; ; ; ;Steckler, M. S.; Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York ;Piana Agostinetti, N.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Wilson, C. K.; Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York ;Roselli, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Seeber, L.; Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York ;Amato, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Lerner-Lam, A.; Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York; ; ; ; ; ; While the upper crustal structure of the Southern Apennines is known, lack of control on the deep structure allows competing thin-skinned and thick-skinned models of the orogen. In thin-skinned models, the detachment decouples a stack of rootless nappes from the basement. In thick-skinned models, basement is involved in the most recent phase of thrusting. To examine crustal structure, we use teleseismic data from the Calabria-Apennine-Tyrrhenian/Subduction- Accretion-Collision Network (CAT/SCAN) array in southern Italy. We use receiver functions (RF) processed into a common conversion point stack to generate images of the crust. Inter- pretation and correlation to geological structure are done using inversions of individual station RFs. We focus on a shallow discontinuity where P-to-S conversions occur. In the foreland, it corresponds to velocity jumps between carbonate and clastic strata with basement. A similar interpretation for the Apennines provides the most parsimonious explanation and supports a thick-skinned interpretation. In a thick-skinned reconstruction, the amount of shortening is much smaller than for a thin-skinned model. This implies considerably less Pliocene–Pleistocene shortening across the Apennines and suggests an east-southeast motion of the Calabrian arc subparallel to the southern Apennines rather than a radial expansion of the arc.595 102