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Strike-slip tectonics between the Marsica Range and the Molisan Basin in the Sangro Valley (Abruzzo, Central Italy)
No full textTectonic and environmental evolution of Quaternary intramontane basins in Southern Apennines (Italy): insights from paleomagnetic and rock magnetic investigations
No full textSouthern Apennines is characterized by active extensional tectonics with NE–SW stretching
direction. The seismicity of the region is very well understood and continuously monitored. In
contrast, the onset of extensional tectonics is chronologically poorly constrained. The aim of
this study is that to give important constraints on the development of extensional regime and
the onset of the continental deposition during Quaternary in Southern Apennines.
We report the results of palaeomagnetic and rock magnetic analyses from four Quaternary
small intramontane basins in the PicentiniMountains (Southern Apennines). The sedimentary
sequences are located at different altitudes, from 600 to 1200 m a.s.l., and were deposited in
fluvial-lacustrine environments. We sampled 29 sites in clays and lacustrine limestones from
Tizzano, Piano del Gaudo and Acerno basins and in red palaeosoils and matrix-supported
conglomerates from the Iumaiano basins. In the clay and limestones samples magnetite,
titano-magnetite, hematite and iron-sulphide have been recognized as the main magnetic
carriers, whereas magnetite and hematite characterize the Iumaiano conglomerates and red
soils. Palaeomagnetic results have been integrated with published radiometric data in order to
constrain the age of each sedimentary basins. Sites from the Iumaiano basin, which represents
the substrate of the Tizzano and Piano del Gaudo basins, show a reverse polarity and therefore
have been attributed to the lower Matuyama chron. In contrast, palaeomagnetic data from
Tizzano basin show a transition from reversed to normal polarity along the exposed section,
which has been interpreted as the Matuyama/Brunhes transition. Sites from Acerno and Piano
del Gaudo basins show a normal polarity, which, according to radiometric and pollen data,
have been correlated to the Brunhes epoch. On the base of such results we discuss the tectonostratigraphic
evolution of the basins and the role of extensional tectonics in this portion of the
Southern Apennine during the Quaternary
The sedimentary substrate of the Colli Albani volcano
No full textThe structure, age and facies distribution of the sedimentary substrate of the Colli
Albani volcano has been investigated by analysing sedimentary xenoliths enclosed in pyroclastic
and phreatomagmatic deposits from different eruptive centres of the volcano, for comparison with
the stratigraphies of deep wells drilled in the area and the known surface geology of the areas surrounding
the volcano. Thin-section analysis has been carried out on the same xenolith samples collected
and discussed by Funiciello and Parotto (1978. Il substrato sedimentario nell’area dei Colli
Albani: considerazioni geodinamiche e paleogeografiche sul margine tirrenico dell’Appennino
Centrale. Geologica Romana, 17, 233–287.) and Amato and Valensise (1986. Il basamento sedimentario
dei Colli Albani: risultato di uno studio degli ejecta dei crateri idromagmatici di Albano e
Nemi. Memorie Societa` Geologica Italiana, 35, 761–767.), largely from the maars deposits of the
most recent Via dei Laghi period of activity of the volcano. The pre-orogen marine stratigraphic
sequences range from Late Triassic?–Lower Lias to Middle Miocene, with carbonate platformto-
basin facies. These sequences are very similar to those cropping out in the Sabina area to the
north and NE of the volcano. Upper Cretaceous carbonate platform units, similar to those cropping
out in the Lepini Mts, to the east of the volcano, have been recognized only in the xenoliths from the
Nemi maar. Similar to that observed in the outcropping geology of the Sabina region, no evidence
of siliciclastic xenoliths related to the Upper Miocene foredeep units have been found. The Upper
Miocene?–Lower Pliocene to Upper Pliocene post-orogen marine sedimentary cycle has been
recognized in almost all the eruptive centres, and has similarities with the sedimentary units
present in the Rome area. The absence of marine Quaternary sediments among the xenolith
types suggests that the Colli Albani area was continental before the onset of volcanism
Relationship between AMS and folding in an area of superimposed folding (Cotiella-Bóixols nappe, Southern Pyrenees)
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MAGNETIC FABRIC OF WEAKLY DEFORMED CLAY SEDIMENTS IN THE ITALIAN PENINSULA: RELATIONSHIP WITH COMPRESSIONAL AND EXTENSIONAL TECTONICS
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