1,017 research outputs found

    Fluids mobilization in Arabia Terra, Mars: depth of pressurized reservoir from mounds self-similar clustering

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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

    Mapping of major volcanic structures on Pavonis Mons in Tharsis, Mars

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    Pavonis Mons, with its 300 km of diameter and 14 km of height, is one of the largest volcanoes of Mars. It rests on a topographic high called Tharsis rise and it is located in the centre of a SW-NE trending row of volcanoes, including Arsia and Ascraeus Montes. In this study we mapped and analyzed the volcanic and tectonic structures of Pavonis Mons in order to understand its formation and the relationship between magmatic and tectonic activity. We use the mapping ArcGIS software and vast set of high resolution topographic and multi-spectral images including CTX (6 m/pixel) as well as HRSC (12.5 m/pixel) and HiRiSE (∼0.25 m/pixel) mosaic images. Furthemore, we used MOLA (∼463 m/pixel in the MOLA MEGDR gridded topographic data), THEMIS thermal inertia (IR-day, 100 m/pixel) and THEMIS (IR-night, 100 m/pixel) images global mosaic to map structures at the regional scale. We found a wide range of structures including ring dykes, wrinkle ridges, pit chains, lava flows, lava channels, fissures and depressions that we preliminary interpreted as coalescent lava tubes. Many sinuous rilles have eroded Pavonis’ slopes and culminate with lava aprons, similar to alluvial fans. South of Pavonis Mons we also identify a series of volcanic vents mainly aligned along a SW-NE trend. Displacements across recent crater rim and volcanic deposits (strike slip faults and wrinkle ridges) have been documented suggesting that, at least during the most recent volcanic phases, the regional tectonics has contributed in shaping the morphology of Pavonis. The kinematics of the mapped structures is consistent with a ENE-SSW direction of the maximum horizontal stress suggesting a possible interaction with nearby Valles Marineris. Our study provides new morphometric analysis of volcano-tectonic features that can be used to depict an evolutionary history for the Pavonis Volcano

    Structural analysis of grabens, Pit Chains and rifting in Noctis Labyrinthus (Mars) based on data derived from HRSC and MOLA.

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    ResearchAims: 1. Study the tectonic features and the stress field in NoctisLabyrinthus. 2. Scrutinize the PitChainsmorohologyand evolution. 3. Reveal the processes responsible for the complex ramify rift systems and troug

    IO9 GEOPLANET Field Trip Guide

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    This document has been prepared by the University of Padova in collaboration with the University D’Annunzio and the whole consortium of the Erasmus+ Strategic Partnership GeoPlaNet-SP (ref. 2020-1-FR01-KA203-079773) with a more consistent effort from University of Nantes personnel. This Intellectual provide a comprehensive overview of some key sites on the Dolomites similar to geological environments on Mars. The field guide is focused on the Upper Permian sedimentary environment of semi-arid alluvial plains, the Upper Permian Lower-Triassic coastal and shallow marine sequences and the Quaternary periglacial morphologies. The main sites of interest are the Bletterbach Gorge, the San Pellegrino Pass and the Rolle Pass. The guide describes in detail the most important analogies of the sites with specific Martian geological settings and provides geological maps of each site

    OMNICAM: Bifocal Panoramic Camera for Human and Robotic Exploration

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    Situational awareness is the key for maximizing the return of any operation, both for scientific and engineering assessments. SPACECLICK and INAF propose the OMNICAM, a novel camera system which can capture a 360° context view and an optically magnified portion of the same panorama with a single lens and sensor. The Bifocal Panoramic Lens (BPL) (designed by INAF researchers) is a lens capable of warping a panoramic Field-of-View (FoV) of 360° x 100° and simultaneously a round FoV of 20° in high-resolution. While the panoramic portion is always available for continuous monitoring surrounding environment, assets and ongoing operations, additionally the OMNICAM makes use of a pan/tilt mechanism to provide users of orientation capabilities for the magnified portion of the FoV

    An Integrated Geologic Map of the Rembrandt Basin, on Mercury, as a Starting Point for Stratigraphic Analysis

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    Planetary geologic maps are usually carried out following a morpho-stratigraphic approach where morphology is the dominant character guiding the remote sensing image interpretation. On the other hand, on Earth a more comprehensive stratigraphic approach is preferred, using lithology, overlapping relationship, genetic source, and ages as the main discriminants among the different geologic units. In this work we produced two different geologic maps of the Rembrandt basin of Mercury, following the morpho-stratigraphic methods and symbology adopted by many authors while mapping quadrangles on Mercury, and an integrated geo-stratigraphic approach, where geologic units were distinguished also on the basis of their false colors (derived by multispectral image data of the NASA MESSENGER mission), subsurface stratigraphic position (inferred by crater excavation) and model ages. We distinguished two different resurfacing events within the Rembrandt basin, after the impact event, and four other smooth plains units outside the basin itself. This provided the basis to estimate thicknesses, volumes, and ages of the smooth plains inside the basin. Results from thickness estimates obtained using different methodologies confirm the presence of two distinct volcanic events inside the Rembrandt basin, with a total thickness ranging between 1−1.5 km. Furthermore, model ages suggest that the volcanic infilling of the Rembrandt basin is among the ones that extended well into the mid-Calorian period, when Mercury’s effusive volcanism was previously thought to be largely over

    Structural analysis of sulfate vein networks in Gale crater (Mars)

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    The Curiosity rover's campaign in the Gale crater on Mars provides a large set of close-up images of sedimentary formations outcrops displaying a variety of diagenetic features such as light-toned veins, nodules and raised ridges. Through 2D and 3D analyses of Mastcam images we herein reconstruct the vein network of a sample area and estimated the stress field. Assessment of the spatial distribution of light-toned veins shows that the basin infillings, after burial and consolidation, experienced a sub-vertical compression and lateral extension coupled with fluid overpressure and cracking. Overall, rock failure and light-toned veins formations could have been generated by an overload produced by infilling material within the basin

    The heterogeneous ice shell thickness of Enceladus

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    Saturn's moon Enceladus is the smallest Solar System body that presents an intense geologic activity on its surface. Plumes erupting from Enceladus' South Polar terrain (SPT) provide direct evidence of a reservoir of liquid below the surface. Previous analysis of gravity data determined that the ice shell above the liquid ocean must be 30-40 km thick from the South Pole up to 50° S latitude (Iess et al., 2014), however, understand the global or regional nature of the ocean beneath the ice crust is still challenging. To infer the thickness of the outer ice shell and prove the global extent of the ocean, we used the self-similar clustering method (Bonnet et al., 2001; Bour et al., 2002) to analyze the widespread fractures of the Enceladus's surface. The spatial distribution of fractures has been analyzed in terms of their self-similar clustering and a two-point correlation method was used to measure the fractal dimension of the fractures population (Mazzarini, 2004, 2010). A self-similar clustering of fractures is characterized by a correlation coefficient with a size range defined by a lower and upper cut-off, that represent a mechanical discontinuity and the thickness of the fractured icy crust, thus connected to the liquid reservoir. Hence, this method allowed us to estimate the icy shell thickness values in different regions of Enceladus from SPT up to northern regions.We mapped fractures in ESRI ArcGis environment in different regions of the satellite improving the recently published geological map (Crow-Willard and Pappalardo, 2015). On these regions we have taken into account the fractures, such as wide troughs and narrow troughs, located in well-defined geological units. Firstly, we analyzed the distribution of South Polar Region fracture patterns finding an ice shell thickness of ~ 31 km, in agreement with gravity measurements (Iess et al., 2014). Then, we applied the same approach to other four regions of the satellite inferring an increasing of the ice shell thickness from 31 to 70 km from the South Pole to northern regions. By these findings, we prove the global extent of the ocean underneath the ice crust of the satellite
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