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Arabia Terra is a region of Mars where signs of past-water occurrence are recorded in several landforms. Broad and local scale geomorphological, compositional and hydrological analyses point towards pervasive fluid circulation through time. In this work we focus on mound fields located in the interior of three casters larger than 40 km (Firsoff, Kotido and unnamed crater 20 km to the east) and showing strong morphological and textural resemblance to terrestrial mud volcanoes and spring-related features. We infer that these landforms likely testify the presence of a pressurized fluid reservoir at depth and past fluid upwelling. We have performed morphometric analyses to characterize the mound morphologies and consequently retrieve an accurate automated mapping of the mounds within the craters for spatial distribution and fractal clustering analysis. The outcome of the fractal clustering yields information about the possible extent of the percolating fracture network at depth below the craters. We have been able to constrain the depth of the pressurized fluid reservoir between ∼2.5 and 3.2 km of depth and hence, we propose that mounds and mounds alignments are most likely associated to the presence of fissure ridges and fluid outflow. Their process of formation is genetically linked to the formation of large intra-crater bulges previously interpreted as large scale spring deposits. The overburden removal caused by the impact crater formation is the inferred triggering mechanism for fluid pressurization and upwelling, that through time led to the formation of the intra-crater bulges and, after compaction and sealing, to the widespread mound fields in their surroundings.

The mechanical strength of foliated rocks is typically anisotropic because it varies with the orientation of the foliation relative to the applied principal stresses and commonly depends on phyllosicate content and phyllosicate physical interconnectivity. We constrain the degree of mechanical anisotropy associated with pre-existing planar discontinuities, such as metamorphic foliations and inherited faults, by combining paleostress analysis and meso- and microscale characterization of brittle failure modes in different phyllosilicate-bearing rocks outcropping in the Sierras de Cordoba (SDC) of Central Argentina. The SDC show evidence of a long brittle deformation history from Early Triassic – Present with three distinct brittle deformational events. Each phase caused new strain increments accommodated by the formation of newly-formed faults or by the reactivation of inherited discontinuities. Structural investigations reveal that gneisses and phyllites deformed by different failure modes during the different events. Therefore, we were able to use a conceptual field-scale triaxial experiment by applying a stress model based on normalised slip-tendency analysis. We constrained the friction coefficient for slip along the foliations (μs) and along pre-existing faults (μf) to 0.2 to 0.3 and 0.4, respectively. These values fit independent estimates for similar rocks confirming the potential of our approach for other case studies.

The Euganean Hills of North East Italy have long been recognised as an area characterized by a higher than average natural radiation background. This is due to two main reasons: a) primary lithogenic radiation due to rhyolitic and trachytic outcrops, which are “acidic alkaline” magmatic rocks potentially enriched in uranium and thorium; b) secondary sources related to a geothermal field – widely exploited for spa tourism in the area since the Roman age – producing surface release of radon-enriched fluids. Though radioactivity levels in the Euganean district have been often investigated in the past – including recent works aimed at assessing the radiation doses from radon and/or total gamma radiation – no effort has been put so far into producing a thorough assessment linking radiation protection data to geological-structural features (lithology, faults, water, organic matter content, etc.). This work represents the first part of the interdisciplinary project “Geological and geochemical control on Radon occurrence and natural radioactivity in the Euganean Hills district (North-Eastern Italy)”, aimed at producing detailed results of the actual radiation levels in connection mainly with lithological parameters. A detailed sampling strategy, based on lithostratigraphy, petrology and mineralogy, has been adopted. The 151 rock samples collected were analyzed by high resolution γ-ray spectrometry with ex situ HPGe detectors. Statistical and geostatistical analyses were performed, and outlier values of U and Th – possibly associated with anomalies in the geological formation – were identified. U, Th and K concentration maps were developed using both the entire database and then again after expunging the outliers; the two were then compared. In all maps the highest values can be associated to trachyte and rhyolite lithologies, and the lowest ones to sedimentary formations. The external dose due to natural radionuclides in the soil – the so called terrestrial gamma dose rate – has been calculated using the U, Th and K distribution measured in the bedrock samples.

The direct evidence of volatile elements in Mercury's interior and on its surface is testified by the presence of pyroclastic vents and hollows, respectively, that in some locations could co-occur. For this reason, in this study we analyze the Tyagaraja impact crater to give new insights into the nature of the hollows located on its floor as well as on the pyroclastic vent and associated deposits. By means of MDIS images, we performed a high-resolution geological map to describe the Tyagaraja's geological setting and distinguish its different geological units. Then, we apply a spectral clustering technique able to separate the dataset in different clusters, each one characterized by its spectrum. Through the comparison between the geomorphological and spectrophotometric results we find that the hollows and the pyroclastic deposit in Tyagaraja are characterized by different spectra. Hollows have the bluest spectrum, with a prominent absorption band at 0.63 μm, in addition to a possible combination of bands (or a single broadband) centered at 0.75 μm and 0.83 μm. On the contrary, the pyroclastic deposit presents the reddest spectrum, characterized by a convex curvature. After considering several volatiles candidate minerals and by applying a linear spectral mixing, we find that the composition of the pyroclastic deposit is well described by a combination of sulfides minerals, in agreement with previous results. On the other hand, hollows may be represented by a combination of chloride minerals. This supports the hypothesis that a localized hollows-forming volatile layer enriched in chlorides might have been generated during the differentiation of the impact melts infilling the crater floor. Such results suggest that the volatile material responsible for hollows formation may be different from the volatiles of pyroclastic eruptions and change depending on the location of the hollows in the hosting impact crater.

This work focuses on the 3D modeling and structural analysis of the Monte Testo syn-sedimentary structure, developed in the Early Jurassic Calcari Grigi Group of the Trento carbonate platform (Southern Alps, Italy). Significant changes in the facies architecture of the platform sedimentary units, occurred across a global perturbation of the Carbon cycle at the Sinemurian-Pliensbachian boundary, are associated with evidences of syn-sedimentary tectonics. In particular, an early cemented oolitic sedimentary body with a high initial porosity (Loppio Oolitic Limestone) was broken-up and tilted by a pulse of rifting and overlain by tight marls and marly limestones (lower Rotzo Formation) that display sharp changes in thickness across the syn-sedimentary faults. This complex setting creates conditions potentially favorable to hydrocarbon accumulation. In this work, the Monte Testo structure is presented as a conceptual analogue of a hydrocarbon reservoir that may develop thanks to the overlap of the effects of extensional tectonics and climate change-induced modifications in the carbonate platform facies. A 3D geo-model was realized to obtain information about the genesis and tectonic evolution of the structure. Hence, a potential porosity distribution in the 3D model was evaluated showing that such extensional structure, which has a vertical extent of 500 m and covers an area of 15 km 2 , could have been associated to a total pore volume of 2.24 × 10 7 m 3 at the time of its formation. Results suggest that in rifting contexts the combined effect of syn-sedimentary faulting and facies variations related to perturbations in the global carbon cycle could generate potential reservoirs in carbonate platforms.

Scientific exploration will play an important role in future human missions to the Moon and Mars. Extra-Vehicular Activities (EVA) on the surface of these objects will be supported by a host of technologies driving operations and data collection. In order to enhance the scientific return of each EVA and utilise expertise located on Earth, it is necessary to record, index and store all the scientific information collected on a planetary surface, and rapidly distribute it amongst the relevant mission support personnel in a structured way. How this information is stored and shared amongst mission support elements will make a significant difference to the feedback that can be provided to EVA teams before, during, and after exploratory EVAs. The Electronic Fieldbook (EFB) is an innovative information system, developed by the European Space Agency (ESA) in the context of their astronaut field training courses and test campaigns, composed of deployable hardware and software designed to fulfil this role. The system uses peer-to-peer networking and mesh protocols to provide disruption tolerant data transmission, as well as information harmonisation and sharing among all system users. Its software stack is platform agnostic, and the system is able to interface with external instruments and tools to gather and centralise data. A combination of commercial off the shelf and custom hardware currently supports the EFB network and interfaces. Users can collect scientific data and document sampling procedures through attaching images, instrument readings, written and audio notes, and other metadata, and have it automatically distributed to all authorised users across its network. Through this system, the EFB enables real-time situational awareness to all science instructors and simulated mission support positions, such as mission control, science backrooms, and Intra-Vehicular crew. The EFB has been developed in the context of the CAVES and PANGAEA astronaut training programmes developed by ESA and is targeting deployment in future lunar and Martian human exploration missions.

Grooves represent the evidence of tectonic activity that deformed Ganymede surface during its geologic evolution. In this work, we investigate the main characteristics of Ganymede’s groove populations on four different areas located at the equatorial region of the satellite (Uruk Sulcus, Babylon Sulci, Phrygia Sulcus and Mysia Sulci). Specifically, we analyse i) the grooves length distribution to provide a framework for their evolution and ii) the grooves self-similar clustering to infer their vertical penetration inside Ganymede icy shell. For each dataset, we find that the grooves distribution is well fitted by an exponential-law and a power-law distribution depending on the structure length. This implies the presence of confined structures in a shallow layer of the icy crust (relatively shorter, exponentially-fitted structures) and crustal-scale structures that could theoretically reach the crust-ocean interface (relatively longer, power law-fitted structures). In addition, the existence of two exponential distributions for few datasets suggest that there could be two different system of structure confined within specific mechanical crust layers. The thickness of the penetrated icy shell is retrieved through the self-similar clustering analysis and ranges between 105 and 130 ​km for the examined datasets. This value agrees with independent estimates of the icy shell thickness, ranging between 80 and 150 ​km. Moreover, our results support the hypothesis that a large number of grooves penetrate the brittle icy crust, with sets of fractures vertically confined in different mechanical layers, while the penetration of few interconnected faults underlying longer grooves may interest the whole icy crust above the liquid ocean.

The Gran Paradiso massif, situated in the internal part of the Western Italian Alps, records a complex tectonometamorphic history involving high-pressure metamorphism and subsequent exhumation during retrograde metamorphism. The exact timing of deformation and, consequently, the geodynamic evolution of this part of the Western Alps is still debated and is addressed here by the application of Rb/Sr geochronology, 40Ar/39Ar step heating and 40Ar/39Ar total fusion dating techniques. Geochronological results are presented from shear zone samples in the core of the Gran Paradiso massif (Piantonetto Valley), and in the area closer to the contact with the overlying Piedmont ophiolitic domain (south and southwest of Pont Valsavarenche). The shear zones operated during crustal thinning and exhumation of the Gran Paradiso massif. 40Ar/39Ar step heating results from shear zones in the Piantonetto Valley show acceptable plateau ages that are interpreted to represent two events of mica growth. Similar ages, and an additional younger age cluster, are recognised in the 40Ar/39Ar total fusion analyses, indicating that specific cleavage domains operated at 39.2±0.2, 36.5±0.6 and 33.3±0.4 Ma. P–T pseudosections show a progressive decrease in metamorphic conditions during deformation, suggesting that the age of incipient exhumation and the related deformation in the Piantonetto Valley is equal to or older than 39.2±0.2 Ma. In the Pont area, the last increments of deformation in a top-to-W shear zone postdate 36.6±0.6 Ma (Rb/Sr mineral data), whereas the present-day top-to-Wcontact of the Gran Paradiso massif with the overlying Piedmont domain is dated at 41.2±1.1 Ma (Rb/Sr multi-mineral isochron age). We propose a model that considers exhumation of the Gran Paradiso nappe at 41–34 Ma. During this period, the nappe was coupled with the Zermatt-Saas zone, forming an extruding wedge. The kinematics associated with this wedge involved top-to-W shearing within the Gran Paradiso nappe (e.g. Pont area shear zones) and top-to-E shearing at the top of the extruding wedge (e.g. Orco shear zone). Subsequent deformation (after ~34 Ma) was characterised by coaxial strain involving orogenic-scale backfolding and backthrusting.

International audience; The surface of (21) Lutetia is highly complex with significant interactions between ancient and more recent structures. This work attempts to summarize the surface geomorphology observed using the high resolution images from OSIRIS, the imaging system onboard the European Space Agency's Rosetta spacecraft. A wide range of surface morphologies are seen including heavily cratered terrain, extensive sets of lineaments, young impact craters, and a ridge, the height of which is more than 1/5th of the mean radius of the body. Very young and very old terrains (as inferred from crater densities) are seen in close proximity. The longest continuous lineament is over 80 km long. The lineaments show regional-dependent organization and structure. Several categories of lineament can be described. Lineaments radial to impact craters as seen on other asteroidal bodies are mostly absent. Although the lineaments may be of seismic origin (and possibly the result of several impact-induced events), impacts producing recent large craters place constraints on seismic phenomena. In particular, stronger attenuation of shocks than seen on other asteroidal bodies seems to be required. Inhomogeneous energy transport, possibly matching observed inhomogeneous ejecta deposition may offer explanations for some of the observed phenomena. Some impact craters show unusual forms, which are probably the result of impact into a surface with relief comparable to the resultant crater diameter and/or oblique impact. There is evidence that re-surfacing through landslides has occurred at several places on the object. (C) 2011 Elsevier Ltd. All rights reserved.

The Cinque Torri group (Cortina d'Ampezzo, Italy) is an articulated system of unstable carbonatic rock monoliths located in a very important tourism area and therefore characterized by a significant risk. The instability phenomena involved represent an example of lateral spreading developed over a larger deep seated gravitational slope deformation (DSGSD) area. After the recent fall of a monolith of more than 10000m3, a scientific study was initiated to monitor the more unstable sectors and to characterize the past movements as a fundamental tool for predicting future movements and hazard assessment. To achieve greater insight on the ongoing lateral spreading process, a method for a quantitative analysis of rotational movements associated with the lateral spreading has been developed, applied and validated. The method is based on: i) detailed geometrical characterization of the area by means of laser scanner techniques; ii) recognition of the discontinuity sets and definition of a reference frame for each set, iii) correlation between the obtained reference frames related to a specific sector and a stable external reference frame, and iv) determination of the 3D rotations in terms of Euler angles to describe the present settlement of the Cinque Torri system with respect to the surrounding stable areas. In this way, significant information on the processes involved in the fragmentation and spreading of a former dolomitic plateau into different rock cliffs has been gained. The method is suitable to be applied to similar case studies. © 2010 Elsevier B.V.

The release of tributyltin (TBT) from maritime traffic represents one of the main problems of direct, diffuse, and continued contamination of the marine environment. In the present survey, the concentrations of TBT and dibultytin (DBT) in brackish waters, sediments, and the gastropods Nassarius nitidus were evaluated in order to estimate the contamination of the southern part of the Venice lagoon. TBT and DBT were determined by GC-MS/MS. Recent contamination of TBT was found in brackish waters near marinas, whereas the highest concentrations of TBT and DBT were observed in surface sediments at dockyards and harbours. High content of organotin in the gastropods sampled near the dockyards, harbours, and marinas showed a mobilisation from the sediments through the food web. The present study allowed assessment of whether, despite the ban on the use of TBT paints, waters, sediments, and biota were still being contaminated by organotin compounds in the southern Venice lagoon.

The southern basin of the Venice Lagoon has been the focus of fewer studies concerning contamination from heavy metals than the northern and central basins. A recent increase in urban waste waters from Chioggia town, as well as dockyards, shipping and fishing activities, affect this part of the lagoon. The aim of this study was to investigate the total mercury (THg) incidence in sediments and Nassarius reticulatus gastropods in order to assess its distribution and evaluate the level of contamination. THg concentration measured in bottom sediments ranged between 0.1 and 3.4 mg/kg d. wt. The enrichment factor (EF) showed high values (avg. 30, max 49) near the dockyards of Chioggia; the lowest (avg. 9, max 17) were found in the coastal marine sediments near the port entrance of the southern basin. THg in marine scavenger gastropods accumulated in N. reticulatus with concentrations falling within the range of 0.3-1.3 mg/kg d. wt. A positive correlation was found between THg concentration in sediments and in N. reticulatus in all sites, excluding the dockyards. A first local cause for mercury pollution might be attributed to the antifouling paints used in great quantity in the recent past near the town of Chioggia. Moreover, fine suspended sediments associated with tidal flushing are suggested as possibly being the vehicle for pollutant dispersal from the Marghera industrial area to the whole of Venice's lagoon.

Even a relatively small earthquake can become a study case if the seismological data are augmented with non-conventional information, such as geodetic and hydrological data. This could be the case of the M = 4.8 earthquake of 17 July 2001 with epicentre near Merano, in northern Italy, where a 4-year long time series of the permanent GPS station MERA, a few kilometers from the epicentre, and water table data from four wells within 8 km of the estimated epicenter are available. A steplike signal in the time series of the geodetic coordinates of MERA is found to be simultaneous with the epoch of the earthquake. If such jump is interpreted as a coseismic displacement, the fault plane solution of this strike slip earthquake is constrained in a manner, which is consistent with the general tectonic setting of the area. Geodetic and seismological data are used to constrain the depth of the hypocenter. We show that the fault dislocation data and the geodetic displacement of the GPS station clearly support the hypothesis of a shallow earthquake (

Data from remote sensing, structural geology and thermochronology provide the basis for this integrated reconstruction of the Oligocene to Present kinematic evolution of the north-western Alpine nappe stack. Two brittle tectonic phases post-date the Cretaceous–Eocene ductile deformation. A NW–SE extension developed in the Oligocene (D1) along three main conjugate fault systems arranged in orthorhombic symmetry (N-, NW- and SE-dipping). Cooling rate contour maps, from published apatite and zircon fission-track ages and Rb/Sr biotite ages, highlight the differential exhumation of large fault-bounded blocks during this phase, whilst synkinematic hydrothermal veins and calc-alkaline dykes (29–32 Ma) help to constrain its age. From the Miocene onwards, a general rearrangement of the strain pattern led to SW-directed lateral extrusion (D2) of the Pennine-Graian Alps block, bounded by a network of seismogenic shear zones, the most important being the Ospizio Sottile, Simplon, Rhone and Chamonix faults. The internal deformation of the Pennine-Graian Alps block is characterised by an overall more or less homogeneous NE–SW extension. The approach undertaken, integrating remote sensing, structural analysis on different scales, and thermochronology (with the cooling rate map representation), is therefore effective in reconstructing the late-orogenic extensional tectonic evolution of metamorphic nappe stacks.

Erratum to “Laser scanning-based recognition of rotational movements on a deep seated gravitational instability: The Cinque Torri case (North-Eastern Italian Alps)” [Geomorphology 122 (2010) 191–204] Alessia Viero⁎, Giordano Teza, Matteo Massironi , Michel Jaboyedoff , Antonio Galgaro a Dipartimento di Geoscienze, Universita di Padova, via Giotto, 1, I-35137 Padova, Italy b Dipartimento di Ingegneria dell'Informazione,Universita di Padova,via Gradenigo, 6/B, I-35131, Padova, Italy c Institut de Geomatique et de l'analyse du risque, Universite de Lausanne, Amphipole, CH-1015 Lausanne, Switzerland