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Structural setting of internal Ligurian units from Polcevera and Scrivia valleys Ligurian Apennines


, : Structural setting of internal Ligurian units from Polcevera and Scrivia valleys Ligurian Apennines. Bollettino della Societa Geologica Italiana 119(2): 321-338

The structural and geological field-mapping of the Polcevera and Scrivia valleys (Genoa Province) has revealed the presence of four tectonic units located between the Sestri-Voltaggio Zone and the Antola Unit. These units will be hereafter referred as: Bric Montaldo unit, Serra Ricco unit, Vallecalda unit and Ciae unit. All these units consist of turbiditic sequences. In addition, the Serra Ricco unit is characterized by the presence of pebbly mudstone deposits. The pre-Oligocene structural evolution of Bric Montaldo, Serra Ricco, Vallecalda and Ciae units is characterized by a polyphase deformation pattern with strong similarities showing the deformation history recognized in the Internal Ligurid Units. Each tectonic unit is affected by at least three main pre-Oligocene deformation phases, with the development of multiple generations of folds and thrust surfaces. The first deformation phase (D (sub 1) ) is marked by non cylindrical isoclinal to sub-isoclinal F (sub 1) folds (axis trend N180E-N200E) associated with cataclastic shear zones. The S (sub 1) axial plane foliation is markedly penetrative and well developed in fine grained lithology, where it can be classified as slaty-cleavage. The D (sub 1) phase is characterized by a non-coaxial deformation history, with a top-to-west sense of shear. The metamorphic peak conditions were reached during this phase. The study of mineralogical parameters (mineral assemblages, "crystallinity", polytypism and b (sub 0) of illite, as well as the "crystallinity" of chlorite) point to very low-grade conditions for all the units, with an increase of metamorphic grade from the highest to the lowest tectonic unit. The second deformation phase (D (sub 2) ) consists of sub-cylindrical asymmetric folds (axis trend N160E-N180E), with approximately parallel geometry, associated with a crenulation cleavage. F (sub 2) folds consistently show westward vergence. During this phase, all pre-existing structural elements including the thrusts between the tectonic units, are deformed. The third deformation phase (D (sub 3) ) is characterized by large, open folds with subvertical axial plane roughly N-S trending. Lithostratigraphic features and structural evolution of Bric Montaldo, Serra Ricco, Vallecalda and Ciae units strongly support the interpretation of the successions from this units as palaeogeographically belonging to the Late Cretaceous turbiditic successions of the Internal Ligurid Domain, with a tectonic evolution developed in the same palaeotectonic setting. Particularly, lithostratigraphic features and structural stack of the Internal Ligurid Units from Valpolcevera show strong similarities with the tectonic units cropping out in the high Trebbia and Aveto Valleys.

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Other references

Magnin, F.; Kofman, J.; Perrin Fayolle, M.; Brun, J., 1971: Local treatment of lung and pleural aspergillomas exclusive of exeresis. In 4 yr, 29 cases were treated by destruction of the aspergilloma by speleotomy, speleo-pleurectomy or by pleurectomy with endocavitary drainage or pleural drainage combined with instillation of antimycotic drugs, particularly amphotericin B.

Armbruster T.; Gunter M.E., 1991: Stepwise dehydration of a natural clinoptilolite; a single-crystal X-ray study at 100 K. Eos, Transactions, American Geophysical Union: 7, Pages 146. 1991.

Walker, R.A., 1988: The histopathological evaluation of nucleolar organizer region proteins. Histopathology 12(2): 221-223

Henwood, K.Sammut.; Browne, K.Dominic.; Chou, S., 2016: A Randomized Controlled Trial Exploring the Effects of Brief Anger Management on Community-Based Offenders in Malta. NlmCategory="UNASSIGNED">The aim of this article is to examine the effects of a short-term one-to-one anger management program delivered to community-based offenders in Malta. The program delivered was the Individual Managing Anger Pr...

Shapiro, J.A., 1993: Natural genetic engineering of the bacterial genome. The term 'natural genetic engineering' means viewing genetic change as a coordinated cell biological process, the reorganization of discrete genomic modules, resulting in the formation of new DNA structures. Examples of natural genetic e...

Sokolov, E.N.; Nezlina, N.I.; Polyanskii, V.B.; Evtikhin, D.V., 2002: The orientating reflex: the "targeting reaction" and "searchlight of attention". A concept of the orientating reflex is presented, based on the principle of vector coding of cognitive and executive processes. The orientating reflex is a complex of orientating reactions of motor, autonomic, and subjective types, accentuating ne...

Bernard, C.; Laverdiere, M.R., 1992: Spatial redistribution of Cs-137 and soil erosion on Orleans Island, Quebec. Cs-137 redistribution data were used to estimate the extent and pattern of long-term soil erosion in the Quebec City area, Canada. Mean annual net soil movements ranging from a deposition of 10.8 t/ha per yr to a loss of 31.8 t/ha per yr were esti...

Rodríguez-Lázaro, D.; Ariza-Miguel, J.; Diez-Valcarce, M.; Fernández-Natal, I.; Hernández, M.; Rovira, J., 2015: Foods confiscated from non-EU flights as a neglected route of potential methicillin-resistant Staphylococcus aureus transmission. The emergence of methicillin-resistant Staphylococcus aureus (MRSA) in food-producing animals has provoked a great concern in the presence of MRSA in associated foodstuff. In this study, we have assessed for the first time the presence of MRSA in...

Bond, AB., 1983: The foraging behaviour of lacewing larvae on vertical rods. A series of laboratory experiments was carried out in the USA on the foraging behaviour of 2nd-instar larvae of Chrysoperla carnea (Steph.) (Chrysopa carnea). The effects of spatial complexity on foraging and the information requirements of the un...

Lienhart David A.; Stransky Terry E., 1985: Laboratory testing as an aid in the design of cable anchor systems for rock reinforcement. Proceedings of the Annual Highway Geology Symposium 36: 220-237