83 research outputs found

    Structural analysis of the Victoria quadrangle (H2) of Mercury based on NASA MESSENGER data

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    Objective of this thesis is the mapping and structural analysis of the H2 quadrangle, "Victoria", and a reconnaissance study of the geometry and kinematics of lobate scarps on Mercury. To this end, I produced a 1:3,000,000 geologic map of the area using the images provided by the NASA spacecraft MESSENGER, which has been orbiting the planet since March 2011. The structural analysis was supplemented by an innovative method to calculate fault slip data using craters cross-cut by lobate scarps. This method permits to fully constrain remotely-sensed fault kinematics, and it was applied on 16 craters found across 30% of Mercury covered by stereo-DTM data. Inversion of fault slip data gathered within the quadrangle thus allowed the estimation of the orientation of the stress field pertaining to the mapped lobate scarp systems

    Geology of the Shakespeare quadrangle (H03), Mercury

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    By using images acquired by the Mercury dual imaging system (MDIS) on-board the MESSENGER spacecraft during 2008–2015 and available DTMs, a new 1:3,000,000-scale geological map of the Shakespeare quadrangle of Mercury has been compiled. The quadrangle is located between latitudes 22.5°–65.0°N and longitudes 270.0°–180.0°E and covers an area of about 5 million km2. The mapping was based on photo-interpretation performed on a reference monochromatic basemap of reflectance at 166 m/pixel resolution. The geological features were digitized within a geographic information system with a variable mapping scale between 1:300,000 and 1:600,000. This quadrangle is characterized by the occurrence of three main types of plains materials and four basin materials (pertaining to the Caloris basin), whose geologic boundaries have been here redefined compared to the previous map of the quadrangle. The stratigraphic relationships between the craters were based on three main degradation morphologies. Furthermore, previously unmapped tectonic landforms were detected and interpreted as thrusts or wrinkle ridges

    European Co-ordinated Quadrangle Mapping of Mercury

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    MESSENGER data are being used to create 1:3M quadrangle geologic maps of Mercury, in preparation for BepiColombo. Maps H02-H05 have already been published and others are in progress or scheduled with the exception of H01. Mapping uses 166 mpp mosaics, and digitization is at a scale of 1:300k. The mapper for each quadrangle maps a 5° overlap with adjacent quadrangles, and it will be possible to produce a globally merged product. Mapping protocols follow the mapping standards document of the Planmap project, which are modelled closely on the USGS equivalent

    BepiColombo MCAM Channels Spice Kernels Optimization

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    The aim of this document is to define the correction to be implemented on the Spice Kernels (SK) of the BepiColombo Monitoring-CAMera (MCAM) to improve the geometric definition of the pinhole models (intrinsic parameters of the cameras) and their pointing (extrinsic parameters) with respect to the BepiColombo Space Craft reference frame

    Geologic Map of the Shakespeare Quadrangle (H03), Mercury

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    A 1:3M geological map of the H03 Shakespeare quadrangle of Mercury has been compiled through photointerpretation of the MESSENGER images. The most prominent geomorphological feature is the Caloris basin, the largest impact crater on Mercury

    MOD derived pyrochlore films as buffer layer for all-chemical YBCO coated conductors

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    We report a detailed study performed on La2Zr2O7 (LZO) pyrochlore material grown by Metal-Organic Decomposition (MOD) method as buffer layers for YBa2Cu3O7-x (YBCO) coated conductors. High quality epitaxial LZO thin films have been obtained on single crystal (SC) and Ni-5%at.W substrates. In order to evaluate structural and morphological properties, films have been characterized by means of X-ray diffraction analyses (XRD), atomic force microscope (AFM) and scanning electron microscope (SEM). Precursors solutions and heat treatments have been studied by thermogravimetric analyses (TG-DTA-DTG) and infrared spectra (FT-IR) with the aim of optimizing the annealing process. Thin films of YBCO have been deposited by pulsed laser ablation (PLD) on this buffer layers. The best results obtained on SC showed YBCO films with critical temperature values above 90 K, high self field critical current density values (Jc > 1 MA/cm2) and high irreversibility field values (8.3 T) at 77 K together with a rather high depinning frequency vp (0.5 T, 77 K)>44 GHz as determined at microwaves. The best results on Ni-5%at.W has been obtained introducing in the heat treatment a pyrolysis process at low temperature in air in order to remove the residual organic part of the precursor solution

    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

    Geology of the Kuiper quadrangle (H06), Mercury

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    The geological map is available as supplemental material at: https://www.tandfonline.com/doi/suppl/10.1080/17445647.2022.2035268The Kuiper quadrangle (H06) is located at the equatorial zone of Mercury and encompasses the area between 288°E–360°E and 22.5°N–22.5°S. Using the NASA MESSENGER data, we compiled a geological map of the quadrangle at a 1:3,000,000 scale. The mapping was mainly based on photo-interpretation of an MDIS (Mercury Dual Imaging System) monochrome 166 m/pixel basemap. Additional datasets were also considered: stereo-DTM of the region, mosaics with high-incidence illumination, and the MDIS global color mosaic. The map shows that the quadrangle is characterized by the prevalence of crater materials which are distinguished into three classes based on their degradation degree. Different plain units were also identified and classified on the basis of their density of cratering. Several structures, mainly represented by contractional faults, were mapped in all quadrangle areas. The map represents the first complete geologic survey of H06 at this scale and provides a highly detailed analysis of the Kuiper quadrangle’s surface geology

    Geologic map and structural analysis of the Victoria quadrangle (H2) of Mercury based on NASA MESSENGER images

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    The first stratigraphic and geologic study of Mercury was released by Trask & Guest (1975) followed by Spudis & Guest (1988, and references therein), whose work was based on the images taken by Mariner 10 covering 42% of the total surface of Mercury. The planet has been officially divided into fifteen quadrangles: 2 polar, 5 equatorial and 8 at midlatitudes. Quadrangle H2 (= Hermes sheet n.2), named ``Victoria'' (20°N - 65°N Lon.; 270°E - 0° Lat.), was partially mapped by McGill & King (1983), though a wide area (∼64%) remained unmapped due to the lack of imagery. Following the terrain units recognized and described by the above authors, we have produced a geologic map of the entire quadrangle using MESSENGER (MErcury Surface, Space ENvironment, GEochemistry and Ranging) images. The images taken by the Mercury Dual Imaging System (MDIS) Wide Angle Camera (WAC) and Narrow Angle Camera (NAC) allowed us to map geologic and tectonic features in much greater detail than the previously published map (mapping scale range between 1:300k and 1:600k). We classified craters larger than 20 km using three relative age classes, which are a simplification of the past five degradation classes defined by McCauley et al. (1981). Victoria quadrangle is characterized by a localized N-S thrust array constituted by Victoria Rupes, Endeavour Rupes and Antoniadi Dorsum to the East and by a more diffuse system of NE-SW oriented fault arrays to the West: the two systems seem to be separated by a tectonic bulge. The Victoria-Endeavour-Antoniadi system has been interpreted as a fold-and-thrust belt by Byrne et al. (2014) and a previous study made on craters cross-cut by its thrusts reveals fault dips of 15-20o and a near dip slip motion (Galluzzi et al., 2015). This geologic map has the aim to build a regional model of its structural framework. Deciphering the geological setting of this quadrangle will bring important insights for understanding the tectonic evolution of the whole planet. Moreover, the results obtained with this study can help in the future targeting choices of the BepiColombo SIMBIOSYS instruments
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