Fig 9 - uploaded by Alan D Pitts
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-Panoramic view from Fano Adriano of the Laga Formaaon (ME1 Sequence, Early Messinian) in the Poggiombricchio area. Thick-bedded sandstone lobes of the Poggiombricchio TSG I onlap without any lateral shaling-out over the foreland ramp represented by the Marne con Cerrogna Fm. (Early Tortonian). The onlap surface is quite steep: 6/8°.
Source publication
The Central portion of the Periadriatic Basin is a N-S oriented foreland basin system associated to the Central Apennine Outer Orogenic Wedge. This system stretches along the Marche and Abruzzi regions and is an excellent example of an evolving mountain chain and associated deep-marine to fluvial-alluvial foredeep and wedge-top basins system.
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Contexts in source publication
Context 1
... the stop view point in the field, it is possible to observe the upper part of the lower Messinian (preevaporiic) ME1 Sequence, which is clearly characterized by an overall fining-upward trend (Fig. 9). The volume variaon is here aributed to the gradual reestablishment of the equilibrium profile in the source area, aer a major deformaon phase (Late Tortonian U1 unc.). The analysed succession is represented by the deposits of three vercally stacked turbidite systems (TS), in stragraphic order: Poggiombricchio, Altavilla and Sgrima ...
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... (Late Tortonian U1 unc.). The analysed succession is represented by the deposits of three vercally stacked turbidite systems (TS), in stragraphic order: Poggiombricchio, Altavilla and Sgrima Turbidite Systems. These TSs are characterized by two Miocene Marne a Orbulina and the underlying Miocene Marne con Cerrogna mainly formed by marlstones (Fig. 9). The marine onlap surface is quite steep: between 6° and 8°. From the stop view point, it is possible to note the stragraphic terminaon, with no lateral shaling-out, of the sandstone beds of the Poggiombricchio TSG I ). The absence of lateral facies variaon has been referred to a combinaon of two different factors: the turbidity ...
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... normal to the paleoshoreline and reveals a wide spectrum of beachface and shoreface deposits produced by wave-and storm-related processes (Fig. 38). The gravelly beachface deposits show considerable variaons in textural and bedding characteriscs in down dip direccon (Massari and Parea, 1988;Cantalamessa and Di Celma, 2004). In the upper beachface (Fig. 39a), conglomerates display disnct segregaon of clasts of different sizes into discrete beds and occur as laterally connuous, well-developed and packed beds consisng of both openwork and clast-supported framework infilled with a fine-to coarse-grained sandy matrix. Clasts are subrounded to rounded, moderately spherical to highly disk-shaped ...
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... Clasts are dominantly spherical and rod-shaped, ranging in size from pebbles to s mall b o u ld ers . At th e to e o f th e b eachface, conglomerates interfinger with a sand-prone facies associaon dominated by trough-filling, landwarddipping (backset) laminae flaening and converging seaward into thinner and finer grained plane-parallel laminae (Fig. 39b). These sediments are interpreted to have been deposited by in the proximal upper shoreface by storm-generated backwash flows during the transiion in flow regime from supercrical to subcrical. The transiion from the proximal to the distal upper-shoreface sediments records a significant increase of preserved wave ripples and burrowed ...
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New report for specimens of Tectura rubroradiata Chirli & Forli, 2017, in tuscan Pleistocene
Citations
... Ghielmi et al., 2010, 2013Artoni, 2013;Rossi et al., 2015), here we name allogroups and LSS boundaries as following: ME3, PL1, PL2, PL3, PS1, PS2, PS3a, PS3b (Fig. 2). This new subdivision follows Amadori et al. (2019) and Ghielmi et al. (2019) in considering the Gelasian as the first stage of the Pleistocene epoch within the Quaternary period, starting at 2.58 Ma. The late Messinian sea-level drop caused a huge subaerial erosion that affected the Venetian-Northern Adriatic area generating deep incised valleys and channels (Ghielmi et al., 2010;Donda et al., 2013Donda et al., , 2015Rossi et al., 2015;Toscani et al., 2016;Amadori et al., 2018). ...
This work reconstructs the complex evolution of a coastal wedge in response to Pliocene tectonic activity and Pleistocene climate change recorded in the upper Neogene subsurface succession of the Friulian-Venetian Basin (FVB), since the latest Messinian sea-level drop event to the late Pleistocene. The FVB is the north-eastern portion of the wider Po Plain-Adriatic foreland basin (Northern Italy), which bounds to the east the whole Italian peninsula and is the place where most of the Italian hydrocarbon offshore fields presently occur. Also, the city of Venice and its surrounding lagoon is presently one of the sites most sensitive to land subsidence worldwide and even a few mm loss of ground elevations can significantly change the natural lagoon environments and threaten the city's survival. To this purpose, we have integrated seismics and well logs analysis with 1D-geohistory modelling on wells, using corrected paleobathymetric data, in order to extract decompacted sedimentation rates. The new age model is based on a complete chronostratigraphic revision of the continuously cored Venezia 1 well, correlated with other 12 hydrocarbon wells to form proper geological depth-calibrated profiles across the basin. Results suggest a major tectonic control on marine sedimentation and basin accommodation space changes during the entire Pliocene-early Pleistocene time, influenced by the Northern Apennines thrust fronts migration. On the contrary, the mid-upper Pleistocene deposition, characterized by a weak deformation, is mainly controlled by climate and basin geometry. During the early mid Pleistocene, an impressive progradational cycle (in the literature usually named “Sabbie di Asti group”) followed the deposition of deep-water turbidites; in this work, we subdivide the different clastic bodies the formation is made of. The uppermost part of the “Sabbie di Asti group” is dominated by shallow-water to continental deposits showing a prominent regressive-transgressive cyclicity, where unfortunately chronological ties are limited. Nevertheless, 6 main cycles driven by 100 kyr Milankovitch-type ciclicity, were laterally correlated by means of the well electric logs and linked to marine ∂18O isotope and eustatic curves.
When sedimentation rates overtake tectonic rates, the detection of ongoing tectonic deformation signatures becomes particularly challenging. The Northern Apennines orogen is one such case where a thick Plio-Pleistocene foredeep sedimentary cover blankets the fold-and-thrust belt, straddling from onshore (Po Plain) to offshore (Adriatic Sea), leading to subtle or null topo-bathymetric expression of the buried structures. The seismic activity historically recorded in the region is moderate; nonetheless, seismic sequences nearing magnitude 6 punctuated the last century, and even some small tsunamis were reported in the coastal locations following the occurrence of offshore earthquakes. In this work, we tackled the problem of assessing the potential activity of buried thrusts by analyzing a rich dataset of 2D seismic reflection profiles and wells in a sector of the Northern Apennines chain located in the near-offshore of the Adriatic Sea. This analysis enabled us to reconstruct the 3D geometry of eleven buried thrusts. We then documented the last 4 Myr slip history of four of such thrusts intersected by two high-quality regional cross-sections that were depth converted and restored. Based on eight stratigraphic horizons with well-constrained age determinations (Zanclean to Middle Pleistocene), we determined the slip and slip rates necessary to recover the observed horizon deformation. The slip rates are presented through probability density functions that consider the uncertainties derived from the horizon ages and the restoration process. Our results show that the thrust activation proceeds from the inner to the outer position in the chain. The slip history reveals an exponential reduction over time, implying decelerating slip-rates spanning three orders of magnitudes (from a few millimeters to a few hundredths of millimeters per year) with a major slip-rate change around 1.5 Ma. In agreement with previous works, these findings confirm the slip rate deceleration as a widespread behavior of the Northern Apennines thrust faults.
