Possible causes of arc development in the Apennines, central Italy

Abstract

Research Article| September 01, 2009 Possible causes of arc development in the Apennines, central Italy Andrea Billi; Andrea Billi † 1Dipartimento di Scienze Geologiche, Università “Roma Tre,” Largo S.L. Murialdo, 00146 Rome, Italy †E-mail: billi@uniroma3.it Search for other works by this author on: GSW Google Scholar Mara Monica Tiberti Mara Monica Tiberti 2Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Rome, Italy Search for other works by this author on: GSW Google Scholar GSA Bulletin (2009) 121 (9-10): 1409–1420. https://doi.org/10.1130/B26335.1 Article history received: 28 Sep 2007 rev-recd: 21 Nov 2008 accepted: 24 Dec 2008 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Andrea Billi, Mara Monica Tiberti; Possible causes of arc development in the Apennines, central Italy. GSA Bulletin 2009;; 121 (9-10): 1409–1420. doi: https://doi.org/10.1130/B26335.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract In central Italy, the geometry, kinematics, and tectonic evolution of the late Neogene Umbrian Arc, which is one of the main thrusts of the northern Apennines, have long been studied. Documented evidence for orogenic curvature includes vertical-axis rotations along both limbs of the arc and a positive orocline test along the entire arc. The cause of the curvature is, however, still unexplained. In this work, we focus our attention on the southern portion of the Umbrian Arc, the so-called Olevano-Antrodoco thrust. We analyze, in particular, gravity and seismic-reflection data and consider available paleomagnetic, stratigraphic, structural, and topographic evidence from the central Apennines to infer spatial extent, attitude, and surface effects of a midcrustal anticlinorium imaged in the CROP-11 deep seismic profile. The anticlinorium has horizontal dimensions of ~50 by 30 km, and it is located right beneath the Olevano-Antrodoco thrust. Stratigraphic, structural, and topographic evidence suggests that the anticlinorium produced a surface uplift during its growth in early Pliocene times. We propose an evolutionary model in which, during late Neogene time, the Olevano-Antrodoco thrust developed in an out-of-sequence fashion and underwent ~16° of clockwise rotation when the thrust ran into and was then raised and folded by the growing anti clinorium (late Messinian–early Pliocene time). This new model suggests a causal link between midcrustal folding and surficial orogenic curvature that is consistent with several available data sets from the northern and central Apennines; more evidence is, however, needed to fully test our hypothesis. Additionally, due to the occurrence of mid-crustal basement-involved thrusts in other orogens, this model may be a viable mechanism for arc formation elsewhere. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.