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Risultati dello svuotamento latero-cervicale funzionale associato a radioterapia post-operatoria in 102 casi di carcinomi laringei con metastasi linfonodali
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From a deformed Peri-Tethyan carbonate platform to a fold and thrust belt: an example from Central Apennines (Italy).
No full textIn the Central Apennines of Italy, the relationships between the foreland deformation of a Peri-Tethyan carbonate platform (Lazio–Abruzzi domain) and the subsequent contractional pattern have been clearly documented by means of stratigraphic and structural evidence. Stratigraphic and structural data point out the occurrence of pre-thrusting normal fault systems, and allow us to define their relationships with contractional structures. Miocene normal faults are particularly well documented by thickness and facies variation of foredeep deposits and by structural evidence. These faults controlled sedimentation during Tortonian–Early Messinian times (foredeep stage), and produced most of the accommodation space for clastic deposits in their hanging-walls. On the contrary, the subsequent positive inversion appears to be quite limited, and generally the hanging-wall sequences are not uplifted above the regional. Clear evidence that normal faults formed first and were later cut and/or rotated during thrusting is supported by analyses carried out along the main fault surfaces. The restoration of a balanced geological section across the study area, based on the inference of an extended foreland affected by later contraction, provided a total, small shortening value. This is lower than the previous estimated by several authors, for the same foreland-fold-and-thrust-belt
Structural setting of the Cicolano - M. Calvo area (Central Apennines, Italy)
No full textThe studied area, belonging to the Central Apennines, is comprises
between the M. Filone-M. Navegna ridge in the west, and the
M. Calvo-Colle dei Montanari ridge in the east. Four tectonic units,
characterized by different sedimentary successions and by different
structural setting can be recognized in the area. They form a complex
embricate fan thrust system and are, from the higher to the
lower one: Reatini unit, Navegna unit, Salto-Nuria-Calvo unit, La
Torretta unit.
The Reatini unit is made of the Umbria-Marchean sedimentary
succession, and is tectonically placed on the Navegna and the Salto-
Nuria-Calvo units, by a thrust plane developed along the Ancona-
Anzio Auct. tectonic line. Its internal structural setting is characterized
by a minor thrust plane that placed a syncline involving the
Jurassic deposits on the overturned Cretaceous-Paleogene succession.
A Mesozoic slope-to-basin and a Cenozoic carbonate ramp succession,
developed along the northwestern margin of the Lazio-
Abruzzi carbonate platform paleodomain constitutes the Navegna
unit, located in the south of the Reatini unit. It is overthrust onto
the Salto-Nuria-Calvo unit by a thrust plane which corresponds to
the Olevano-Antrodoco line. Several minor thrust planes associated
to narrow hangingwall anticlines verging eastward in the Navegna
unit have been recognized.
The Salto-Nuria-Calvo unit can be divided in three sector
belonging to the Lazio-Abruzzi carbonate platform paleodomain: the
sedimentary succession of the Salto sector is made up of Cretaceous
carbonate platform deposits, covered unconformably by a Miocene
succession of carbonate ramp environment, and by a thick Early
Messinian siliciclastic turbidites succession. The internal structural
setting comprises minor folds and thrust planes that constitute carbonate
ridges surrounded by siliciclastic deposits. On the eastern
side of Salto lake, small carbonate ridges sometimes associated to
back thrust planes occur.
The M. Nuria sector is made of a Mesocenozoic sedimentary
succession deposited in a carbonate platform environment, that passes
southeastward to carbonate margin deposits. The stratigraphic
organization shows a progressive sinking of this sector during Cretaceous-
Paleogene time. Miocene carbonate ramp and Early Messinian
siliciclastic turbiditic deposits cover unconformably the previous
ones.
This unit is organized in anticlines associated to thrust plane
trending NW-SE. Minor back thrust planes and splays with thin levels
of turbiditic sandstone cropping out in their footwall, can be
observed in the eastern sector of the area. M. Calvo sector, constituted
by a Mesozoic carbonate platform margin sedimentary succession,
is the more external part of the the Lazio-Abruzzi carbonate
platform paleodomain, and it overthrusts with a low angle thrust
plane onto the more external unit of La Torretta unit, that is, on its
turn, made of the Meso-Cenozoic pelagic succession. The M. Calvo
area is organized in several minor tectonic slides, while its footwall
(La Torretta unit) shows narrow synclines and anticlines with an
inclined to overturned setting.
Tear faults associated to the compressive structures, trending
SW-NE and E-W, are also recognized.
From the Late Pliocene on, an extensional tectonic phase occurs
in the studied area with the development of main normal faults and the reactivation of some ancient structures
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