scholarly journals Syn‐orogenic exhumation of high‐P units by upward extrusion in an accretionary wedge: Insights from the Eastern Elba nappe stack (Northern Apennines, Italy)

Tectonics ◽  
2021 ◽  
Author(s):  
E. Ryan ◽  
S. Papeschi ◽  
G. Viola ◽  
G Musumeci ◽  
F Mazzarini ◽  
...  
Keyword(s):  
Northern Apennines ◽  
Accretionary Wedge

scholarly journals Miocene Seep-Carbonates of the Northern Apennines (Emilia to Umbria, Italy): An Overview

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 53
Author(s):  
Stefano Conti ◽  
Claudio Argentino ◽  
Chiara Fioroni ◽  
Aura Cecilia Salocchi ◽  
Daniela Fontana
Keyword(s):  
Regional Scale ◽  
Field Research ◽  
Northern Apennines ◽  
Climate Forcing ◽  
Continental Margins ◽  
Accretionary Wedge ◽  
Geological Processes ◽  
Oxygen Stable Isotopes ◽  
Active Continental Margins ◽  
Seep Carbonate

The natural emission of methane-rich fluids from the seafloor, known as cold seepage, is a widespread process at modern continental margins. The studies on present-day cold seepages provide high-resolution datasets regarding the fluid plumbing system, biogeochemical processes in the sediment, seafloor seepage distribution and ecosystems. However, the long-term (hundreds of thousands to millions of years) evolution of cold seepage remains elusive. The identification and study of outcrop analogous now exposed on land represent a valuable method for better understanding the effects of geological processes and climate forcing on the development of cold seepage systems. Here, we provide an overview on Miocene seep-carbonate deposits of the northern Apennines (from Emilia to the Umbria-Marchean sector, Italy), based on decades of field research integrated with detailed sedimentological and geochemical investigations. We report a total of 13 seep-carbonate outcrops, which formed in three different structural settings of the paleo-accretionary wedge corresponding to wedge-top basins, outer slope and intrabasinal highs at the deformational front. We discuss the recurring lithostratigraphic occurrence of seep deposits and the main compositional features (carbonate facies, carbon and oxygen stable isotopes) in order to interpret the seepage dynamics, duration and infer the contribution of methane-rich fluids released by paleo-gas hydrates. The datasets presented in this study represent a valuable complete record of cold seepage spanning ~12 Myr, that can be used to better understand factors controlling the regional-scale spatial and temporal evolution of cold seepage systems at modern active continental margins.

Structural characterization of the wedge - top Epiligurian Units in the framework of the Northern Apennines tectonic evolution (northern Italy)

2021 ◽  
Author(s):  
Francesca Stendardi ◽  
Gianluca Vignaroli ◽  
Giulio Viola
Keyword(s):  
Tectonic Evolution ◽  
Middle Eocene ◽  
Sedimentary Cover ◽  
Northern Apennines ◽  
Coarse Grained ◽  
Normal Faults ◽  
Accretionary Wedge ◽  
Deformation Bands ◽  
Deformation Structures ◽  
Emilia Romagna Region

<p>The Northern Apennines are an accretionary wedge formed in response to the Late Cretaceous-Eocene closure of the Ligurian-Piedmont ocean and the subsequent Oligocene-Miocene convergence and collision between Africa and Europe. The wedge is formed by a stack of different paleogeographic units which, from the innermost to the outermost and from top to bottom, are: (i) the Ligurian Domain (formed by Jurassic ophiolites and their Cretaceous-to-Paleocene sedimentary cover); (ii) the Sub-Ligurian Domain (Paleocene-to-lower Miocene deep marine sediments and turbidites); (iii) the Tuscan-Umbria-Marche Domain (mostly including Jurassic-to-Oligocene platform and basinal carbonate successions, overlain by Miocene-Pliocene turbidites). The wedge is shaped by WNW-ESE-striking and SW-dipping thrusts, accommodating a general northeastward tectonic transport. Atop of the deformed Ligurian Domain there occur the Epiligurian Units, which consist of middle Eocene-upper Miocene bathyal to shallow-water siliciclastic deposits infilling wedge-top basins. These Units presently fill in separate basins with poor lateral interconnectivity due to erosion and deformation. Since the Miocene, thrusting toward the (eastern) orogenic foreland occurred simultaneously with extension in the (western) hinterland domain, causing the formation of NW-SE-striking normal faults. Presently, focal mechanisms of the stronger earthquakes constrain dominant thrusting associated with NE-SW regional shortening, whereas the extensional regime controls the seismicity along the axial portion of the wedge. This recently launched study aims to better characterize the deformation structures affecting the Epiligurian Units in the internal and external sectors of the Northern Apennines (Emilia-Romagna Region) with the goal to provide a comprehensive syn-to-post accretion evolutionary scenario for these shallow basins. In particular, deformation structures affecting these wedge-top sequences of the inner (southwestern) side of the wedge are being studied by their systematic geometric and kinematic multiscalar and multitechnique characterization. Top-to-the NE, WNW-ESE-striking thrusts/reverse faults, dipping moderately to SSW are defined by planar slip surfaces associated with thin clastic damage zones. Top-to-the SE, ENE-WSW-striking thrusts/reverse faults, are instead generally devoid of well-developed damage zones. These contractional faults are systematically cut by NW-SE and NE-SW-striking normal and oblique faults systems, characterized by mutually intersecting fault planes accommodating centimetric to decimetric throws. Associated with the extensional structures occur widespread cataclastic and disaggregation deformation bands. They are found as either single bands or clusters, cutting across upper Eocene coarse-grained sandstones. Our preliminary results show that the Epiligurian Units experienced a complex tectonic evolution, including NNE-SSW shortening followed by NE-SW extension. The structural record of these wedge top basins is useful to infer the kinematics and rate of wedge build up and tearing down during the progressive evolution of the continental collision. The Epiligurian Units can thus be considered as useful gages of the deformation history of the Northern Apennines wedge, with noteworthy implications on its current seismotectonic setting.</p>

scholarly journals From accretion to exhumation in a fossil accretionary wedge: a case history from Gottero unit (Northern Apennines, Italy)

2004 ◽  
Vol 17 (1) ◽  
pp. 41-53 ◽  
Author(s):  
Michele Marroni ◽  
Francesca Meneghini ◽  
Luca Pandolfi
Keyword(s):  
Case History ◽  
Northern Apennines ◽  
Accretionary Wedge

The geological structure of the Emilia-Tuscany Northern Apennines and Alpi Apuane

2019 ◽  
Vol 11 (2.5) ◽  
pp. 1-78 ◽  
Author(s):  
Paolo Conti ◽  
Gianluca Cornamusini ◽  
Luigi Carmignani ◽  
Giancarlo Molli
Keyword(s):  
Geological Structure ◽  
Northern Apennines

Mozartite, CaMn(OH)SiO 4 , a new mineral species from the Cerchiara Mine, northern Apennines, Italy

1993 ◽  
Vol 31 (2) ◽  
pp. 331-336 ◽  
Author(s):  
R. Brasso ◽  
G. Lucchetti ◽  
L. Zefiro ◽  
A. Palenzona
Keyword(s):  
Northern Apennines ◽  
Mineral Species ◽  
New Mineral ◽  
New Mineral Species
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