scholarly journals Hypothesis for the mechanics and seismic behaviour of low-angle normal faults: the example of the Altotiberina fault Northern Apennines

2009 ◽  
Vol 45 (5) ◽  
Author(s):  
C. Collettini
Keyword(s):  
Northern Apennines ◽  
Normal Faults ◽  
Seismic Behaviour

The development and behaviour of low-angle normal faults during Cenozoic asymmetric extension in the Northern Apennines, Italy

2006 ◽  
Vol 28 (2) ◽  
pp. 333-352 ◽  
Author(s):  
C. Collettini ◽  
N. De Paola ◽  
R.E. Holdsworth ◽  
M.R. Barchi
Keyword(s):  
Northern Apennines ◽  
Normal Faults

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>

Late evolution of the inner Northern Apennines from the structure of the Monti del Chianti-Monte Cetona Ridge (Tuscany, Italy)

2021 ◽  
Author(s):  
Andrea Brogi
Keyword(s):  
Middle Miocene ◽  
Sedimentary Basins ◽  
Northern Apennines ◽  
Normal Faults ◽  
Tyrrhenian Sea ◽  
Scientific Debate ◽  
Marine Deposits ◽  
Accommodation Space ◽  
Tectonic Events ◽  
Late Evolution

<p>The Neogene and Quaternary tectonic evolution of the inner Northern Apennines (i.e southern Tuscany and northern Tyrrhenian Sea), as well as its crustal features (i.e. low crustal thickness, Neogene-Quaternary magmatism, widespread geothermal anomalies, lateral segmentation of the stacked tectonic units, extensive deep sedimentary basins), are framed in different geodynamic scenarios: compressional, extensional or both, pulsing. Consequently, the basin and range structure that characterises the northern Tyrrhenian Sea and southern Tuscany is considered as a consequence of (i) out-of-sequence thrusts and related thrust-top-basins, (ii) polyphased normal faulting that formed horst and graben structures or (iii) a combination of both. This paper provides a new dataset from a sector of the eastern inner Northern Apennines (i.e. Monti del Chianti - Monte Cetona ridge) contributing to this scientific debate. New fieldwork and structural analysis carried out in selected areas along the ridge allowed to define the chronology of the main tectonic events on the basis of their influence on the marine and continental sedimentation. The dataset supports for early Miocene - (?) Serravallian in-sequence and out-of-sequence thrusting. Thrusting produced complex staking patterns of Tuscan and Ligurian Units. Extensional detachments developed since later middle Miocene and controlled the Neogene sedimentation in bowl-shaped structural depressions, later dissected by normal faults enhancing the accommodation space for Pliocene marine deposits in broad NNW-trending basins (Siena-Radicofani and Valdichiana Basins). In this perspective, no data supports for active, continuous or pulsing, compressional tectonics after late Serravalian. As a result, in the whole inland inner Northern Apennines the extensional tectonics was continuously active at least since middle Miocene and controlled the basins development, magmatism and structure of the crust and lithosphere.</p>

Fault structure and slip localization in carbonate-bearing normal faults: An example from the Northern Apennines of Italy

2014 ◽  
Vol 67 ◽  
pp. 154-166 ◽  
Author(s):  
C. Collettini ◽  
B.M. Carpenter ◽  
C. Viti ◽  
F. Cruciani ◽  
S. Mollo ◽  
...  
Keyword(s):  
Northern Apennines ◽  
Normal Faults ◽  
Fault Structure

scholarly journals Polyphase extensional basins: interplay between tectonics and sedimentation in the Neogene Siena-Radicofani Basin (Northern Apennines, Italy)

2021 ◽  
Author(s):  
Ivan Martini ◽  
Elisa Ambrosetti ◽  
Andrea Brogi ◽  
Mauro Aldinucci ◽  
Frank Zwaan ◽  
...  
Keyword(s):  
Northern Apennines ◽  
Sediment Supply ◽  
Coarse Grained ◽  
Normal Faults ◽  
Rift Basins ◽  
Base Level ◽  
Accommodation Space ◽  
Sedimentary Evolution ◽  
Half Graben

AbstractRift-basins are the shallow effects of lithosphere-scale extensional processes often producing polyphase faulting. Their sedimentary evolution depends on the mutual interplay between tectonics, climate, and eustasy. Estimating the role of each factor is generally a challenging issue. This paper is focused on the tectono-sedimentary evolution of the Neogene Siena-Radicofani Basin, a polyphase structural depression located in the inner Northern Apennines. Since Miocene, this basin developed after prolonged extensional tectonics, first as a bowl-shaped structural depression, later reorganized into a half-graben structure due to the activation of high-angle normal faults in the Zanclean. At that time the basin contained coeval continental and marine settings controlled by the normal faulting that caused the development of local coarse-grained depositional systems. These were investigated to: (i) discriminate between the influences of tectonics and climate on sedimentation patterns, and (ii) provide detailed time constraints on fault activity. The analysed successions were deposited in an interval between 5.08 and 4.52 Ma, when a climate-induced highstand phase occurred throughout the Mediterranean. However, evidence of local relative sea-level drops is registered in the sedimentary record, often associated with increased accommodation space and sediment supply. Such base-level fluctuations are not connected to climate changes, suggesting that the faults generally control sedimentation along the basin margins.

scholarly journals Syn-thrusting polygonal normal faults exposed in the hinge of the Cingoli anticline, northern Apennines, Italy

2015 ◽  
Vol 3 ◽  
Author(s):  
Lorenzo Petracchini ◽  
Marco Antonellini ◽  
Andrea Billi ◽  
Davide Scrocca
Keyword(s):  
Northern Apennines ◽  
Normal Faults
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