Aerial inventory of surficial geological effects induced by the recent Emilia earthquake (Italy): preliminary report.

As a consequence of the two main shocks that recently struck the central alluvial Po Plain (May 20, 2012, ML 5.9, and May 29, 2012, ML 5.8), a great number of surficial geologic disturbances appeared over a wide area (ca. 500 km2), which extended up to 20 km from the epicenters. The affected area includes Mirabello, San Carlo, Sant'Agostino (Province of Ferrara), San Felice, Cavezzo, Concordia (Modena), Moglia and Quistello (Mantova). Most of the surficial effects that were observed during this study were clearly induced (directly or indirectly) by sand liquefaction phenomena, such as sand volcanoes, burst of water and sand from domestic wells, tension cracks, lateral spreading and associated deformation, graben-like fracturing, and sink-holes. Other effects can probably be ascribed simply to the shaking of the ground (e.g., small collapses of irrigation canal walls). Lastly, there were also some features of dubious origin, such as two 'yellow crop spots' that are cited here with reservations. All of these data were surveyed by means of a small airplane that was especially adapted for this purpose. The aim of this study was to furnish a wide-ranging image of the surface deformation over the whole area impacted by these recent earthquakes, as an instrument towards more exhaustive research, both at the scientific and technical levels (e.g., seismic microzonation)

Constraining the fluid source of Miocene seep carbonates using radiogenic Sr isotopes (Corella outcrop, northern Apennines, Italy)

Analisi isotopiche e biostratigrafiche su corpi carbonatici metanoderivati dell'Appennino settentrional

STRONTIUM ISOTOPE STRATIGRAPHY AS A CONTRIBUTION FOR DATING MIOCENE SHELF CARBONATES (S. MARINO FM., NORTHERN APENNINES)

This paper provides new data on strontium isotope stratigraphy applied to the Miocene heterozoan shelfal carbonates of the S. Marino Fm. (Marecchia Valley, northern Apennines). Sr isotopic analyses were carried out on oyster shells, bryozoans and bulk-rocks from the lower-middle carbonate portion of the section. In the upper part of the succession that shows evidence of detrital influx, 87Sr/86Sr analyses were performed on foraminifera tests, separating planktonic and benthic forms. Results were compared with calcareous nannofossil biostratigraphic data from the same levels, in order to test the reliability of Sr dating in mixed carbonate-siliciclastic sediments. Mean ages obtained from oysters range between 16.9 Ma and 16.3 Ma. Very similar results are obtained using bryozoans (16.5 Ma to 16.1 Ma) and bulk-rocks (16.8 Ma to 16.2 Ma). These results allow to better constrain the age of the massive carbonate shelf, referable to the upper Burdigalian. In the upper carbonate-siliciclastic portion of the shelf, numerical ages obtained from planktonic and benthic foraminifera are in good agreement with nannofossil biozones (mean ages respectively around 15.3 Ma and 14.5 Ma) although they display wide confidence intervals. These wide age uncertainties depend on the slow rate of change of marine 87Sr/86Sr through time that characterizes the interval between ~15 and ~13.5 Ma

The Eurasian epicontinental sea was an important carbon sink during the Palaeocene-Eocene thermal maximum

The Palaeocene-Eocene Thermal Maximum (ca. 56 million years ago) offers a primary analogue for future global warming and carbon cycle recovery. Yet, where and how massive carbon emissions were mitigated during this climate warming event remains largely unknown. Here we show that organic carbon burial in the vast epicontinental seaways that extended over Eurasia provided a major carbon sink during the Palaeocene-Eocene Thermal Maximum. We coupled new and existing stratigraphic analyses to a detailed paleogeographic framework and using spatiotemporal interpolation calculated ca. 720–1300 Gt organic carbon excess burial, focused in the eastern parts of the Eurasian epicontinental seaways. A much larger amount (2160–3900 Gt C, and when accounting for the increase in inundated shelf area 7400–10300 Gt C) could have been sequestered in similar environments globally. With the disappearance of most epicontinental seas since the Oligocene-Miocene, an effective negative carbon cycle feedback also disappeared making the modern carbon cycle critically dependent on the slower silicate weathering feedback.</p

Il paesaggio geologico dei gessi triassici

This paper presents a virtual excursion “inside” the landscape of the Triassic Gypsum Formation and the upperSecchia Valley. It proposes an aerial view that, through different viewpoints, allows the observer to recogniseelements of the landscape that are difficult to see from the ground, such as the long faults shapingthe steep slopes and the largest landslides of the Emilia-Romagna Apennines. The broad bed of the Secchiariver flows in a straight course for 5.5 kilometres between towering rock-faces of white, pink and lightgray gypsum, rising up 200 metres in some point. Triassic Gypsum contains a number of different lithologies:gypsum, anhydrites, dolomite and quartzite, which form a distorted rock structure with fragments of layersthat present ruptures and folding. They were deposited during the Upper Triassic (215-200 million years ago)and therefore are the oldest rock outcrops in the Emilia-Romagna Apennines. The linear shape of the mainversants is interrupted by lateral valleys drawn by the tectonics, such as the Sologno and The Dorgola valleys.These numerous morphological features make this landscape unique within the Apennines. The steepgradients, coupled with instability brought about by karstic phenomena, make this a suggestive but highlyinhospitable area