A global permittivity map of the Martian surface from SHARAD and some geological correlations

We present the first global SHARAD permittivity map of the Martian surface and use it to constrain the subsurface geology inferred from other data sources. Geological correlations are discussed at the dichotomy boundary, Elysium Mons, and high-latitude ice-filled craters

Hydrothermal Alteration of Ultramafic Rocks in Ladon Basin, Mars - Insights From CaSSIS, HiRISE, CRISM, and CTX

The evolution of the Ladon basin has been marked by intense geological activity and the discharge of huge volumes of water from the Martian highlands to the lowlands in the late Noachian and Hesperian. We explore the potential of the ExoMars Trace Gas Orbiter/Color and Stereo Surface Imaging System color image data set for geological interpretation and show that it is particularly effective for geologic mapping in combination with other data sets such as HiRISE, Context, and Compact Reconnaissance Imaging Spectrometer for Mars. The study area displays dark lobate flows of upper Hesperian to early Amazonian age, which were likely extruded from a regional extensional fault network. Spectral analysis suggests that these flows and the underlying rocks are ultramafic. Two distinct altered levels are observed below the lobate flows. The upper, yellow-orange level shows hundreds of structurally controlled narrow ridges reminiscent of ridges of listwanite, a suite of silicified, fracture-controlled silica-carbonate rocks derived from an ultramafic source and from serpentine. In addition to serpentinite, the detected mineral assemblages may include chlorite, carbonates, and talc. Kaolin minerals are detected in the lower, white level, which could have formed by groundwater alteration of plagioclase in the volcanic pile. Volcanism, tectonics, hydrothermal activity, and kaolinization are interpreted to be coeval, with hydrothermal activity and kaolinization controlled by the interactions between the aquifer and the hot, ultramafic lobate flows. Following our interpretations, East Ladon may host the first listwanite ridges described on Mars, involving a hydrothermal system rooted in a Hesperian aquifer and affecting ultramafic rocks from a magmatic source yet to be identified

Data for: Nanotopographic characterization of microfractures in rocks by Atomic Force Microscopy

DATASET D1 AFM nanoscale topography of the Udokan basalt sample (Fig. 2c) in ASCII format.DATASET D2 AFM nanoscale topography of the Ogaden basalt sample (Fig. 2f) in ASCII format

Data for: Nanotopographic characterization of microfractures in rocks by Atomic Force Microscopy

DATASET D1 AFM nanoscale topography of the Udokan basalt sample (Fig. 2c) in ASCII format.DATASET D2 AFM nanoscale topography of the Ogaden basalt sample (Fig. 2f) in ASCII format.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Infrared spectrometric data of basaltic Martian analogues from Mongolian terranes and the Baikal Rift Zone

Introduction Infrared spectroscopy has been used to analyse the composition of the rock material of basaltic Martian analogues from Mongolian terranes and the southern part of the Baikal Rift Zone, for comparison of the results with those of Martian missions. Collected samples of basalts derive from various geologic environments (rift zone, island-arc, ophiolite). Microscopic observations in thin sections show diversification of composition and structures of basalts. The most diversified are basalts from the Mandalovoo terrane [1]. Transmittance data Transmittance spectra of the samples have been recorded in the range from 400 to 2000 cm−1 for the particle size &lt;25 μm (Fig. 1). The results indicate the presence of the main components of basalts (plagioclases, pyroxenes and olivines), in different proportions, accessory minerals (leucite, analcime) and often of the products of their alteration, e.g. saponite [1]. Comparison with the long wavelength channel data of the Planetary Fourier Spectrometer of the Mars Express mission indicates similar absorption bands of clinopyroxenes in both spectra [1]. Emissivity measurements As the next step of the spectroscopic analysis of these basalts, measurements of the emissivity have been taken in the Planetary Emissivity Laboratory (PEL) at the DLR, Berlin, using a Fourier transform infrared spectrometer Bruker VERTEX 80v in the wavelength range from 3 to 50 μm. For each sample we measured the spectra of four particle size ranges: &lt;25 μm, 25-63 μm, 63-125 μm and 125-250 μm (Fig. 2). Using both such wavelength and particle size ranges enlarges the possibilities of observations, interpretation and comparison with the spectrometric data from Martian missions. For the interpretation of the spectra we are using the Berlin Emissivity Database (BED), which presently contain all the most important mineral components of basaltic analogs [2]. According to the previous interpretation, the spectra show distinct absorption bands of plagioclases and pyroxenes. Presence of other characteristic bands of minerals in the spectra usually reflects the intensity of alteration of the basalts. References [1] Gurgurewicz J. and Kostylew J. (2007) EPSC2007-A-00260. [2] Maturilli A. et al. (2008) Planet. Space Sci., 56, 420-425.<br /

Modelling the influence of the emittance of weathered basaltic materials on radiance spectra - related to observations of Valles Marineris region on Mars

Currently developed studies on simulated radiance of the surface and atmosphere of Mars are presented. Laboratory measurements of spectral emissivity of basaltic materials with various particle size ranges and degree of weathering were used in calculations in order to account for real variations as a function of wavelength. The works presented here are directly connected with the spectrometric measurements during Mars Express mission. Our studies can be useful in analysis of geological and mineralogical properties of Valles Marineris region on Mars