Skip to Main Content
Skip Nav Destination
GEOREF RECORD

Mid-Eocene giant slope failure (sedimentary melanges) in the Ligurian accretionary wedge (NW Italy) and relationships with tectonics, global climate change and the dissociation of gas hydrates

Andrea Festa, Simona Cavagna, Edoardo Barbero, Rita Catanzariti and Gian Andrea Pini
Mid-Eocene giant slope failure (sedimentary melanges) in the Ligurian accretionary wedge (NW Italy) and relationships with tectonics, global climate change and the dissociation of gas hydrates
Journal of the Geological Society of London (August 2019) 177 (3): 575-586

Abstract

Upper Lutetian-Bartonian sedimentary melanges, corresponding to ancient mud-rich submarine mass transport deposits, are widely distributed over an area c. 300?km long and tens of kilometres wide along the exhumed outer part of the External Ligurian accretionary wedge in the Northern Apennines. The occurrence of methane-derived carbonate concretions (septarians) in a specific tectonostratigraphic position below these sedimentary melanges allows us to document the relationships among a significant period of regional-scale slope failure, climate change (the Early and Mid-Eocene Optimum stages), the dissociation of gas hydrates and accretionary tectonics during the Ligurian Tectonic Phase (early-mid-Lutetian). The distribution of septarians at the core of thrust-related anticlines suggests that the dissociation of gas hydrates was triggered by accretionary tectonics rather than climate change. The different ages of slope failure emplacement and the formation of the septarians support the view that the dissociation of gas hydrates was not the most important trigger for slope failure. The latter occurred during a tectonic quiescence stage associated with a regressive depositional trend, and probably minor residual tectonic pulses, which followed the Ligurian Tectonic Phase, favouring the dynamic re-equilibrium of the External Ligurian accretionary wedge. Our findings provide useful information for a better understanding of the factors controlling giant slope failure events in modern accretionary settings, where they may cause tsunamis.


ISSN: 0016-7649
EISSN: 2041-479X
Coden: JGSLAS
Serial Title: Journal of the Geological Society of London
Serial Volume: 177
Serial Issue: 3
Title: Mid-Eocene giant slope failure (sedimentary melanges) in the Ligurian accretionary wedge (NW Italy) and relationships with tectonics, global climate change and the dissociation of gas hydrates
Affiliation: Universita di Torino, Dipartimento di Scienze della Terra, Turin, Italy
Pages: 575-586
Published: 20190814
Text Language: English
Publisher: Geological Society of London, London, United Kingdom
References: 105
Accession Number: 2019-082860
Categories: Structural geologyStratigraphy
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. sects., geol. sketch maps
N45°00'00" - N45°10'00", E08°04'60" - E08°34'60"
Secondary Affiliation: Universita di Ferrara, ITA, ItalyCNR, Istituto di Geoscienze e Georisorse, ITA, ItalyUniversita di Trieste, ITA, Italy
Country of Publication: United Kingdom
Secondary Affiliation: GeoRef, Copyright 2020, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data from The Geological Society, London, London, United Kingdom
Update Code: 201944
Close Modal

or Create an Account

Close Modal
Close Modal