Shallow water carbonate platforms (Late Aptian–Early Albian, Southern Apennines) in the context of supraregional to global changes: re-appraisal of palaeoecological events as reflectors of carbonate factory response

Abstract. This paper discusses the palaeoenvironmental significance of the "Orbitolina Level", the microbial carbonates and the Salpingoporella dinarica-rich deposits encased in the Aptian/Albian shallow water carbonate platform strata of Monte Tobenna and Monte Faito (Southern Italy). These facies show a peculiar field appearance due to their color and/or fossil content. In the shallow water carbonate strata, the Late Aptian "Orbitolina Level" was formed during a period of decreasing accommodation space. Microbial carbonates occur in different levels in the composite section. They reach their maximum thickness around the sequence boundaries just above the "Orbitolina Level" and close to the Aptian–Albian transition, and were not deposited during maximum flooding. S. dinarica-rich deposits occur in the lower part of the Monte Tobenna-Monte Faito composite section, in both restricted and more open lagoonal sediments. S. dinarica has its maximum abundance below the "Orbitolina Level" and disappears 11 m above this layer. On the basis of δ13C and δ18O values recorded at Tobenna-Faito, the succession has been correlated to global sea-level changes and to the main volcanic and climatic events during the Aptian. Deterioration of the inner lagoon environmental conditions was related to high trophic levels triggered by volcano-tectonic activity. Microbial carbonates were deposited especially in periods of third-order sea level lowering. In such a scenario, periods of increased precipitation during the Gargasian induced the mobilization of clay during flooding of the exposed platform due to high-frequency sea-level changes, with consequent terrigenous input to the lagoon. This and the high nutrient levels made the conditions unsuitable for the principle carbonate producers, and an opportunistic biota rich in orbitolinids (Mesorbitolina texana and M. parva) populated the platform. In the more open marine domain, the increased nutrient input enhanced the production of organic matter and locally led to the formation of black shales (e.g. the Niveau Fallot in the Vocontian Basin). It is argued that the concomitant low Mg/Ca molar ratio and high concentration of calcium in seawater could have favoured the development of the low-Mg calcite skeleton of the S. dinarica green algae. During third-order sea-level rise, no or minor microbial carbonates formed in the shallowlagoonal settings and S. dinarica disappeared. Carbonate neritic ecosystems were not influenced by the environmental changes inferred to have been induced by the mid-Cretaceous volcanism. The "Orbitolina Level", the microbial carbonates and the Salpingoporella dinarica-rich deposits in the studied Aptian/Albian shallow water carbonate strata are interpreted to be the response to environmental and oceanographic changes in shallow-water and deeper-marine ecosystems.</jats:p

Lagrangian formulation of classical fields within Riemann-Liouville fractional derivatives

The classical fields with fractional derivatives are investigated by using the fractional Lagrangian formulation.The fractional Euler-Lagrange equations were obtained and two examples were studied.Comment: 9 page

Fractional Dynamics from Einstein Gravity, General Solutions, and Black Holes

We study the fractional gravity for spacetimes with non-integer dimensions. Our constructions are based on a geometric formalism with the fractional Caputo derivative and integral calculus adapted to nonolonomic distributions. This allows us to define a fractional spacetime geometry with fundamental geometric/physical objects and a generalized tensor calculus all being similar to respective integer dimension constructions. Such models of fractional gravity mimic the Einstein gravity theory and various Lagrange-Finsler and Hamilton-Cartan generalizations in nonholonomic variables. The approach suggests a number of new implications for gravity and matter field theories with singular, stochastic, kinetic, fractal, memory etc processes. We prove that the fractional gravitational field equations can be integrated in very general forms following the anholonomic deformation method for constructing exact solutions. Finally, we study some examples of fractional black hole solutions, fractional ellipsoid gravitational configurations and imbedding of such objects in fractional solitonic backgrounds.Comment: latex2e, 11pt, 40 pages with table of conten

Subsidence evolution of the Firenze&#8211;Prato&#8211;Pistoia plain (Central Italy) combining PSI and GNSS data

Subsidence phenomena, as well as landslides and floods, are one of the main geohazards affecting the Tuscany region (central Italy). The monitoring of related ground deformations plays a key role in their management to avoid problems for buildings and infrastructure. In this scenario, Earth observation offers a better solution in terms of costs and benefits than traditional techniques (e.g., GNSS (Global Navigation Satellite System) or levelling networks), especially for wide area applications. In this work, the subsidence-related ground motions in the Firenze&ndash;Prato&ndash;Pistoia plain were back-investigated to track the evolution of displacement from 2003 to 2017 by means of multi-interferometric analysis of ENVISAT and Sentinel-1 imagery combined with GNSS data. The resulting vertical deformation velocities are aligned to the European Terrestrial Reference System 89 (ETRS89) datum and can be considered real velocity of displacement. The vertical ground deformation maps derived by ENVISAT and Sentinel-1 data, corrected with the GNSS, show how the area affected by subsidence for the period 2003&ndash;2010 and the period 2014&ndash;2017 evolved. The differences between the two datasets in terms of the extension and velocity values were analysed and then associated with the geological setting of the basin and external factors, e.g., new greenhouses and nurseries. This analysis allowed for reconstructing the evolution of the subsidence for the area of interest showing an increment of ground deformation in the historic centre of Pistoia Town, a decrement of subsidence in the nursery area between Pistoia and Prato cities, and changes in the industrial sector close to Prato

A methodological approach of QRA for slow-moving landslides at a regional scale

Landslides represent a serious worldwide hazard, especially in Italy, where exposure to hydrogeological risk is very high; for this reason, a landslide quantitative risk assessment (QRA) is crucial for risk management and for planning mitigation measures. In this study, we present and describe a novel methodological approach of QRA for slow-moving landslides, aiming at national replicability. This procedure has been applied at the basin scale in the Arno River basin (9100 km(2), Central Italy), where most landslides are slow-moving. QRA is based on the application of the equation risk = hazard (H) × vulnerability (V) × exposure (E) and on the use of open data with uniform characteristics at the national scale. The study area was divided into a grid with a 1 km(2) cell size, and for each cell, the parameters necessary for the risk assessment were calculated. The obtained results show that the total risk of the study area amounts to approximately 7 billion €. The proposed methodology presents several novelties in the risk assessment for the regional/national scale of the analysis, mainly concerning the identification of the datasets and the development of new methodologies that could be applicable over such large areas. The present work demonstrates the feasibility of the methodology and discusses the obtained results

Ground Subsidence Susceptibility (GSS) mapping in Grosseto plain (Tuscany, Italy) based on satellite InSAR data using frequency ratio and fuzzy logic

This study aimed at evaluating and mapping Ground Subsidence Susceptibility (GSS) in the Grosseto plain (Tuscany Region, Italy) by exploiting multi-temporal satellite InSAR data and by applying two parallel approaches; a bivariate statistical analysis (Frequency Ratio) and a mathematical probabilistic model (Fuzzy Logic operator). The Grosseto plain experienced subsidence and sinkholes due to natural causes in the past and it is still suffering slow-moving ground lowering. Five conditioning subsidence-related factors were selected and managed in a GIS environment through an overlay pixel-by-pixel analysis. Firstly, multi-temporal ground subsidence inventory maps were prepared in the study area by starting from two inventories referred to distinct temporal intervals (2003&ndash;2009 and 2014&ndash;2019) derived from Persistent Scatterers Interferometry (PSI) data of ENVISAT and SENTINEL-1 satellites. Then, the susceptibility modelling was performed through the Frequency Ratio (FR) and Fuzzy Logic (FL) approaches. These analyses led to slightly different scenarios which were compared and discussed. Results show that flat areas on alluvial and colluvial deposits with thick sedimentary cover (higher than 20 m) on the bedrock in the central and eastern sectors of the plain are the most susceptible to land subsidence. The obtained FR- and FL-based GSS maps were finally validated with a ROC (Receiver Operating Characteristic) analysis, in order to estimate the overall performance of the models. The AUC (Area Under Curve) values of ROC analysis of the FR model were higher than the ones of FL model, suggesting that the former is a better and more appropriate predictor for subsidence susceptibility analysis in the study area. In conclusion, GSS maps provided a qualitative overview of the subsidence scenarios and may be helpful to predict and preliminarily identify high-risk areas for environmental local authorities and decision makers in charge of land use planning in the study area. Finally, the presented methodologies to derive GSS maps are easily reproducible and could also be applied and tested in other test sites worldwide, in order to check the modeling performance in different environmental settings

Use of PSInSAR data to map highly compressible soil layers

A new approach to the use of Persistent Scatterers (PS) Interferometry data in the reconstruction of the extension of compressible geological bodies is presented. The methodology was applied in the test area of the Tiber River delta (Italy), characterized by the presence of two large marshy zones, known as the Maccarese and Ostia Antica ponds. PSInSARâ\u84¢ data, derived from ERS1/2, ENVISAT and RADARSAT-1 images, and spanning a time interval between 1992 and 2006 were used to verify the possibility to reconstruct the spatial distribution of the peat levels inside the Maccarese and Ostia Antica ponds. Borehole information was analyzed to calibrate the InSAR data and the deformation rates were used to hypothesize the presence of a thick compressible layer where geological information is lacking. Variations in deformation rates registered by the single PS were assumed to be representative of a variation in the stratigraphic asset. The obtained results demonstrate that this approach could be satisfactorily used to investigate wide areas in a short time, reducing the number of boreholes to drill, and it could be a complementary technique to obtain information about the 2D geometry of specific geological levels