%0 Journal Article
%A Martín Chivelet, Javier
%A Palma, Ricardo Manuel
%A López Gómez, José
%A Kietzmann, Diego A.
%T Earthquake-induced soft-sediment deformation structures in Upper Jurassicopen-marine microbialites (Neuquén Basin, Argentina)
%D 2011
%@ 0037-0738
%U https://hdl.handle.net/20.500.14352/43684
%X Penecontemporaneous decimetre-scale soft-sediment deformation structures are reported from the basalpart of the Upper Jurassic–Lower Cretaceous Vaca Muerta Formation, in the Malargüe–Las Leñas area of theback-arc Neuquén Basin (Mendoza Province, Central Andes). The deformed interval (Amarillas bed) is only0.3 to 0.9 m thick but occurs in a wide area, larger than 1500 km2. Its age, determined by ammonitebiostratigraphy, is Early Tithonian.The soft-sediment deformation structures were generated in finely laminated, partially consolidated, organicrich,carbonate microbialites that were deposited in open-marine, poorly oxygenated settings, apparentlydevoid of any significant slope. Those structures include boudins of different sizes and complexity, a variety offolds, normal (listric) dm-scale faults, sub-horizontal detachment surfaces and other features, which are partof several larger-scale, complex slump structures. Deformation was dominantly plastic but near to theductile–brittle field transition.On the basis of the observed soft-deformation structures, their geographic distribution, their lateralhomogeneity, and the geodynamic framework of the basin in which it was generated, the Amarillas bed can betentatively attributed to a large, intermediate-depth earthquake that occurred within the plate that subductedbeneath the Andean continental margin and the Neuquén back-arc basin.
%~