Mass transport deposits overprinted by contractional tectonics: A case study from the southern Apennines of Italy

Giuseppe Palladino (Corresponding Author), Giacomo Prosser, Mario Mario Bentivenga, G Ian Alsop

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3 Citations (Scopus)

Abstract

Mass transport deposits (MTDs), created by gravity-driven deformation of unlithified sediments, and tectonic mélanges produced by contractional deformation are characterized by a similar chaotic appearance. It follows that distinguishing structures formed by soft-sediment deformation during mass transport from those produced by contractional tectonics can be problematic. In fact, deformation occurring along detachment levels may completely obliterate the original sedimentary fabric. Although a number of advances have been made during recent decades, field criteria for discriminating structures within MTDs that are overprinted by later regional contraction are not readily applicable to all the exposed examples. We address some of these general issues through a detailed case study of the Monte Facito Formation in Italy. This Triassic unit was formed during the Africa–Europe continental separation and, since the Miocene, has been involved in contractional deformation during the construction of the Apennines. The Monte Facito Formation consists of a series of stratigraphically coherent units, separated by chaotic and often deformed intervals, whose origin has been previously attributed to either tectonic or sedimentary processes. An example is provided by a characteristic pebbly mudstone (or ‘paraconglomerate’) which has been interpreted as either a Triassic gravity-flow deposit, or alternatively, as a product of shearing along regional contractional detachments during the Miocene. This detailed field-based study allows us to recognize structures related to the depositional processes that created these chaotic intervals, and which can therefore be interpreted as MTDs. We also discriminate structures connected to later contractional tectonics that locally produced intense reworking of the MTDs.
Original languageEnglish
Pages (from-to)849-873
Number of pages26
JournalGeological Magazine
Volume156
Issue number5
Early online date16 Apr 2018
DOIs
Publication statusPublished - 31 May 2019

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Keywords

  • mass transport deposits
  • sedimentary melanges
  • olistostromes
  • tectonic overprint
  • Monte Facito formation
  • Southern Apennines
  • southern Apennines
  • Mass transport deposits
  • sedimentary mélanges
  • Monte Facito Formation
  • TRES PASOS FORMATION
  • SLUMP STRUCTURES
  • GRAVITY-FLOW DEPOSITS
  • MONTE-FACITO FORMATION
  • ACCRETIONARY COMPLEX
  • DEBRIS FLOW
  • NORTHERN CALCAREOUS ALPS
  • PIGEON POINT FORMATION
  • EXTENSIONAL TECTONICS
  • SOFT-SEDIMENT DEFORMATION

ASJC Scopus subject areas

  • Geology

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