Interaction of tectonic, sedimentary, and diapiric processes in the origin of chaotic sediments: An example from the Messinian of Torino Hill (Tertiary Piedmont Basin, northwestern Italy)

Abstract

Research Article| September 01, 2007 Interaction of tectonic, sedimentary, and diapiric processes in the origin of chaotic sediments: An example from the Messinian of Torino Hill (Tertiary Piedmont Basin, northwestern Italy) Francesco Dela Pierre; Francesco Dela Pierre 1Dipartimento di Scienze della Terra, Università di Torino, Via Valperga Caluso 35, 10125 Torino, Italy Search for other works by this author on: GSW Google Scholar Andrea Festa; Andrea Festa 2Consiglio Nazionale delle Ricerche—Istituto di Geoscienze e Georisorse, Via Valperga Caluso 35, 10125 Torino, Italy Search for other works by this author on: GSW Google Scholar Andrea Irace Andrea Irace 3Consiglio Nazionale delle Ricerche—Istituto di Geoscienze e Georisorse, Via Valperga Caluso 35, 10125 Torino, Italy Search for other works by this author on: GSW Google Scholar Author and Article Information Francesco Dela Pierre 1Dipartimento di Scienze della Terra, Università di Torino, Via Valperga Caluso 35, 10125 Torino, Italy Andrea Festa 2Consiglio Nazionale delle Ricerche—Istituto di Geoscienze e Georisorse, Via Valperga Caluso 35, 10125 Torino, Italy Andrea Irace 3Consiglio Nazionale delle Ricerche—Istituto di Geoscienze e Georisorse, Via Valperga Caluso 35, 10125 Torino, Italy Publisher: Geological Society of America Received: 12 Jul 2006 Revision Received: 01 Feb 2007 Accepted: 21 Feb 2007 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2007) 119 (9-10): 1107–1119. https://doi.org/10.1130/B26072.1 Article history Received: 12 Jul 2006 Revision Received: 01 Feb 2007 Accepted: 21 Feb 2007 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Francesco Dela Pierre, Andrea Festa, Andrea Irace; Interaction of tectonic, sedimentary, and diapiric processes in the origin of chaotic sediments: An example from the Messinian of Torino Hill (Tertiary Piedmont Basin, northwestern Italy). GSA Bulletin 2007;; 119 (9-10): 1107–1119. doi: https://doi.org/10.1130/B26072.1 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 Geologic mapping and integrated stratigraphic and structural observations of a gypsum quarry from northwestern Italy allow evaluation of the relative contributions, the time relationships, and the causative links between tectonic, sedimentary, and diapiric processes in the genesis of chaotic sediments of Messinian age. Three chaotic units are exposed in the quarry: together, they make up a composite chaotic unit that is unconformably overlain by post-chaotic sediments. Unit 1 is composed of blocks of primary evaporites that are juxtaposed to marine marls by subvertical transpressive faults and are parallel to the fault surfaces. Unit 2 unconformably overlies Unit 1, and consists of a lenticular sedimentary body containing both angular and rounded blocks, randomly distributed in a fine-grained matrix. Unit 3 consists of a 10-m-wide body bounded by transpressive faults, and pierces both Units 1 and 2. It is composed of strongly deformed muddy deposits that envelop blocks of gypsum and carbonate rocks. Between the core and the margins, various zones have been defined based on the increasing amount of deformation toward the margins. The post-chaotic sediments unconformably overlie both Units 1 and 2, sealing the main fault systems.The composite chaotic unit is related to thrust propagation during a regional phase of deformation, and is the result of different evolutionary stages, in each of which a single genetic mechanism prevailed. Tectonic faulting prevailed during stage 1 and was responsible for the formation of a tectonically disrupted assemblage (Unit 1). During stage 2, gravity-driven sedimentary phenomena, related to slope oversteepening triggered by ongoing thrust propagation, resulted in the deposition of Unit 2. Gravity sliding was favored by the mechanical weakening of sediments caused by tectonic faulting. Over-pressure conditions resulting from the rapid deposition of Unit 2 triggered the rise of a diapir (Unit 3) that pierced Units 1 and 2. The involvement of methane-rich fluids in the formation of the diapir is suggested by the occurrence of blocks of methane-derived carbonates, found not in the quarry, but just outside it. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.