scholarly journals Chronological Analysis and Remote Sensing of Craters on the Surface of Mars

2021 ◽  
Vol 9 ◽  
Author(s):  
Fares M. Howari ◽  
Manish Sharma ◽  
Cijo M. Xavier ◽  
Yousef Nazzal ◽  
Fatima AlAydaroos
Keyword(s):  
Compositional Analysis ◽  
Landing Site ◽  
Surface Characteristics ◽  
High Elevation ◽  
Imaging Spectrometer ◽  
Machine Learning Approach ◽  
Geological Formation ◽  
Southern Side ◽  
Geological Boundaries ◽  
Geological Units

In the present research, we carried out detailed chronological and compositional analyses along with detailed spectral analysis of three unnamed craters on the surface of Mars. Knowledge on chronology/age analysis and compositional analysis of Mars’ surface is essential for future manned and unmanned missions. The study area is near the landing site of previous landed missions, which could be used for future landing. The area is interesting to be studied because of its high elevation in the northeastern side and low elevation in the southern side, consisting of three major geological boundaries, i.e., Hesperian, Noachian, and Amazonian, which are further subdivided into fourteen units. Chronological investigations were carried out using the active machine learning approach and Craterstats 2.0 software, which revealed the age plot of 3.09 ± 0.04 Ga for Amazonian, 3.63 ± 0.0 Ga for Hesperian, and 3.73 ± 0.0 Ga for Noachian geological units, stating that N(1) craters’ density corresponds to the early Amazonian, early Hesperian, and late Noachian/early Hesperian periods according to the established crater density boundaries, respectively. Compact Reconnaissance Imaging Spectrometer for Mars (CRISM)-derived browse products are used for the compositional study of the surface characteristics of Mars. A spectral investigation was performed on an unnamed crater belonging to the Amazonian period, which showed to be majorly composed of oxides as the primary mineral, indicating the spectra of hematite, boehmite, and akaganeite. A Hesperian unit-unnamed crater shows the signature of monohydrated sulfates, melilite, illite, and kaolinite minerals in the region. For the unnamed crater 3, which belongs to the Noachian period, it has diagnostic absorptions of clay minerals in their extracted spectra, indicating the sign of long-term water–rock interactions in the period. Derived chronology results and compositional studies of craters help in better understanding the geological formation units of Mars’ surface.

scholarly journals Atmospheric, Geomorphological, and Compositional Analysis of Martian Asimov and Hale Craters: Implications for Recurring Slope Lineae

2022 ◽  
Vol 8 ◽  
Author(s):  
Fares M. Howari ◽  
Manish Sharma ◽  
Cijo M. Xavier ◽  
Yousef Nazzal ◽  
Fatima Alaydaroos
Keyword(s):  
Compositional Analysis ◽  
Surface Characteristics ◽  
Open Science ◽  
Imaging Spectrometer ◽  
Atmosphere Interaction ◽  
Main Factors ◽  
Recurring Slope Lineae ◽  
Steep Slopes ◽  
Compositional Study ◽  
Observation Period

Recurring slope lineae (RSL) are small, dark, seasonal albedo features lengthening down “warm” Martian steep slopes. Their origin has been attributed to both liquid and dry processes, hence representing one of the major open science questions on present day Mars. In the present study, we report a catalog of previous literature and newly added RSL sites making a total of 940 sites globally on Mars along with the detailed geological and compositional investigation of the Hale and Asimov craters with their RSL features. We also estimate temperature and atmospheric water abundances in the study area, which are two of the main factors to explain the origin and formation of RSL. The study found that the Asimov crater’s local temperatures are high enough to allow either the melting of brines or deliquescence of calcium perchlorate and other salts during the HiRISE observation period and found the water vapor column to be nearly five times higher than those measured “before RSL appearance.” This supports the theory of deliquescence as one of the mechanisms for the regolith-atmosphere interaction and RSL formation in the studied crater, which suggests that minerals absorb moisture from the environment until the minerals dissolve in the absorbed water and yield a solution. We also used compact reconnaissance imaging spectrometer for Mars–derived browse products for a compositional study associated with RSL features hosting craters and surface characteristics of Mars.

scholarly journals Photometric Normalization of Chang’e-4 Visible and Near-Infrared Imaging Spectrometer Datasets: A Combined Study of In-Situ and Laboratory Spectral Measurements

2020 ◽  
Vol 12 (19) ◽  
pp. 3211
Author(s):  
Xiaobin Qi ◽  
Zongcheng Ling ◽  
Jiang Zhang ◽  
Jian Chen ◽  
Haijun Cao ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Imaging ◽  
Landing Site ◽  
Near Infrared Imaging ◽  
Imaging Spectrometer ◽  
Quantitative Mineralogy ◽  
Infrared Spectral ◽  
Phase Functions ◽  
Phase Angles

Until 29 May 2020, the Visible and Near-Infrared Imaging Spectrometer (VNIS) onboard the Yutu-2 Rover of the Chang’e-4 (CE-4) has acquired 96 high-resolution surface in-situ imaging spectra. These spectra were acquired under different illumination conditions, thus photometric normalization should be conducted to correct the introduced albedo differences before deriving the quantitative mineralogy for accurate geologic interpretations. In this study, a Lommel–Seeliger (LS) model and Hapke radiative transfer (Hapke) model were used and empirical phase functions of the LS model were derived. The values of these derived phase functions exhibit declining trends with the increase in phase angles and the opposition effect and phase reddening effect were observed. Then, we discovered from in-situ and laboratory measurements that the shadows caused by surface roughness have significant impacts on reflectance spectra and proper corrections were introduced. The validations of different phase functions showed that the maximum discrepancy at 1500 nm of spectra corrected by the LS model was less (~3.7%) than that by the Hapke model (~7.4%). This is the first time that empirical phase functions have been derived for a wavelength from 450 to 2395 nm using in-situ visible and near-infrared spectral datasets. Generally, photometrically normalized spectra exhibit smaller spectral slopes, lower FeO contents and larger optical maturity parameter (OMAT) than spectra without correction. In addition, the band centers of the 1 and 2 μm absorption features of spectra after photometric normalization exhibit a more concentrated distribution, indicating the compositional homogeneity of soils at the CE-4 landing site.

scholarly journals Bayesian Surface Warping Approach for Rectifying Geological Boundaries Using Displacement Likelihood and Evidence from Geochemical Assays

2022 ◽  
Vol 8 (1) ◽  
pp. 1-23
Author(s):  
Raymond Leung ◽  
Alexander Lowe ◽  
Anna Chlingaryan ◽  
Arman Melkumyan ◽  
John Zigman
Keyword(s):  
Domain Knowledge ◽  
Large Scale ◽  
A Priori ◽  
Compositional Analysis ◽  
Scale Model ◽  
Grade Estimation ◽  
Global Trend ◽  
Large Scale Model ◽  
Geological Boundaries ◽  
Clear Delineation

This article presents a Bayesian framework for manipulating mesh surfaces with the aim of improving the positional integrity of the geological boundaries that they seek to represent. The assumption is that these surfaces, created initially using sparse data, capture the global trend and provide a reasonable approximation of the stratigraphic, mineralization, and other types of boundaries for mining exploration, but they are locally inaccurate at scales typically required for grade estimation. The proposed methodology makes local spatial corrections automatically to maximize the agreement between the modeled surfaces and observed samples. Where possible, vertices on a mesh surface are moved to provide a clear delineation, for instance, between ore and waste material across the boundary based on spatial and compositional analysis using assay measurements collected from densely spaced, geo-registered blast holes. The maximum a posteriori (MAP) solution ultimately considers the chemistry observation likelihood in a given domain. Furthermore, it is guided by an a priori spatial structure that embeds geological domain knowledge and determines the likelihood of a displacement estimate. The results demonstrate that increasing surface fidelity can significantly improve grade estimation performance based on large-scale model validation.

Preservation of organic compounds and constraints on diagenetic processes by reactive iron phases on Mars

2021 ◽  
Author(s):  
Christian Schröder ◽  
Emily Bonsall
Keyword(s):  
Clay Minerals ◽  
Organic Compounds ◽  
Compositional Analysis ◽  
Landing Site ◽  
Earth Planet ◽  
X Ray ◽  
Gale Crater ◽  
Reactive Iron ◽  
Diagenetic Processes ◽  
Fe Species

<p>Over 20% of organic carbon in sediments on Earth are bound to reactive Fe mineral phases [1]. These reactive Fe phases are generally Fe (oxyhydr)oxides, often associated with clay minerals. It is important to note that they occur as nanoparticulate and X-ray amorphous phases that are challenging to identify. On Earth, proxy methods such as chemical sequential extractions are often used but they can produce misleading results when used for mineral identification [2,3]. We develop and use Mössbauer spectroscopy applications to identify these phase [2-4] and compare these to Raman spectroscopy because the Mars 2020 Perseverance rover and the ExoMars 2022 Rosalind Franklin rover use Raman spectrometers for mineralogical identification.</p> <p>Reactive Fe phases are abundant on Mars. It is important to note that they are not the well-crystalline expression of Fe (oxyhydr)oxides such as hematite and goethite that have been observed from orbit and with a variety of rover-based instruments. Instead, reactive Fe phases are represented by as yet unidentified Fe phases: Aqueously altered rocks and soils in Gusev crater and at Meridiani Planum (including the Burns formation) contain large amounts of nanophase iron oxides (npOx and Fe3D3) [5]; and 20-60 wt% of minerals in fluvio-lacustrine deposits in Gale crater are X-ray amorphous and this amorphous phase is rich in iron [6]. Mineralogical interpretation of CRISM data of Rosalind Franklin's landing site at Oxia Planum also suggest the presence of these phase. These reactive Fe phases can be any combination of a number of minerals including ferrihydrite, lepidocrocite, akaganèite, hissingerite, schwertmannite, and superparamagnetic (i.e. nanoparticulate) hematite and goethite [5].</p> <p>The preservation of organic compounds by reactive Fe species is effective over hundreds of thousands of years in Earth sediments [1]. In return, organic compounds slow down the transformation of reactive Fe species such as ferrihydrite into the more crystalline and thermodynamically stable Fe (oxyhydr)oxides hematite or goethite during diagenetic processes. With temperature and pressure rising further during diagenesis, however, organic compounds are oxidized and destroyed through the reduction of Fe (resulting in the diagenetic formation of the Fe carbonate siderite, for example), and the non-reduced Fe species are transformed into thermodynamically stable minerals. Thus, the presence of reactive Fe species in Martian sediments/sedimentary rocks indicates only little diagenetic overprinting and therefore a high preservation potential of organic compounds. Such samples will be of high priority for analysis with MOMA. However, the presence of Fe species during pyrolysis can reduce the detectability of certain organic compounds. This effect depends on the specific Fe species present and is mitigated in the presence of clay minerals [7,8].</p> <p>We will present Mössbauer and Raman spectrocopy investigations of reactive Fe phases in various sedimenatry settings and compare these results into the context of rover landing sites on Mars.</p> <p>References:</p> <p>[1] Lalonde et al (2012) <em>Nature</em> 483, 198-200. [2] Schröder et al (2016) <em>Hyperfine Interact </em>237, 85<em>.</em> [3] Hebpburn et al (2020) <em>Chem Geol</em> 543, 119584. [4] Klingelhöfer et al (2003) <em>J Geophys Res</em> 108(E12), 8067. [5] Morris et al (2019) in <em>Remote Compositional Analysis: Techniques for Understanding Spectroscopy, Mineralogy, and Geochemistry of Planetary Surfaces</em>, pp. 538-554, Cambridge University Press. [6] Rampe et al (2017) <em>Earth Planet Sci Lett</em> 471, 172–185. [7] Tan et al (2021) <em>Astrobiology</em> 21, 199-218. [8] Royle et al (2021) <em>Astrobiology</em> in press. </p>

scholarly journals Olivine-norite rock detected by the lunar rover Yutu-2 likely crystallized from the SPA-impact melt pool

2019 ◽  
Vol 7 (5) ◽  
pp. 913-920 ◽  
Author(s):  
Honglei Lin ◽  
Zhiping He ◽  
Wei Yang ◽  
Yangting Lin ◽  
Rui Xu ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Imaging ◽  
Lunar Regolith ◽  
Thermal Conditions ◽  
Landing Site ◽  
Lunar Crust ◽  
Imaging Spectrometer ◽  
Melt Pool ◽  
Moon Mineralogy Mapper ◽  
The Impact

Abstract Chang’E-4 landed in the South Pole-Aitken (SPA) basin, providing a unique chance to probe the composition of the lunar interior. Its landing site is located on ejecta strips in Von Kármán crater that possibly originate from the neighboring Finsen crater. A surface rock and the lunar regolith at 10 sites along the rover Yutu-2 track were measured by the onboard Visible and Near-Infrared Imaging Spectrometer in the first three lunar days of mission operations. In situ spectra of the regolith have peak band positions at 1 and 2 μm, similar to the spectral data of Finsen ejecta from the Moon Mineralogy Mapper, which confirms that the regolith's composition of the landing area is mostly similar to that of Finsen ejecta. The rock spectrum shows similar band peak positions, but stronger absorptions, suggesting relatively fresh exposure. The rock may consist of 38.1 ± 5.4% low-Ca pyroxene, 13.9 ± 5.1% olivine and 48.0 ± 3.1% plagioclase, referred to as olivine-norite. The plagioclase-abundant and olivine-poor modal composition of the rock is inconsistent with the origin of the mantle, but representative of the lunar lower crust. Alternatively, the rock crystallized from the impact-derived melt pool formed by the SPA-impact event via mixing the lunar crust and mantle materials. This scenario is consistent with fast-cooling thermal conditions of a shallow melt pool, indicated by the fine to medium-sized texture (<3 mm) of the rock and the SPA-impact melting model [Icarus 2012; 220: 730–43].

scholarly journals Mapping Neodymium Model Ages of the Quebecia Terrane Near Saguenay, Quebec

2020 ◽  
pp. 4-12
Author(s):  
Serena Formenti ◽  
Alan Dickin
Keyword(s):  
Age Distribution ◽  
Geological Samples ◽  
Detailed Structure ◽  
Grenville Province ◽  
Geological Evolution ◽  
History Of ◽  
Southern Side ◽  
Geological Units ◽  
Orogenic Events ◽  
Insight Into

The geological evolution of the Grenville Province remains a subject of confusion among geologists. Orogenic events have deformed the original features, making the geology of the area challenging to delineate. This study maps the distribution of crustal formation ages within the Quebecia terrane of the Grenville Province. This provides insight into the crustal provenance of the geological units present. Previous research suggested the presence of slivers of Paleoproterozoic crust (>1.65 Ga) within Pinwarian crust (1.5 Ga). Four geological samples were analyzed from the southern side of the Saguenay graben, where the Paleoproterozoic crustal slivers were thought to extend. Analysis through TDM model ages derived from Sm-Nd radiogenic dating aimed to identify the boundaries of these slivers. Determining the model age distribution within the terrane allows for further delineation of the geological history of the region. The samples analyzed in this study yielded Pinwarian TDM model ages, indicating that slivers of old crust are not present within the study area. These results provide further constraints in the detailed structure of the Quebecia composite arc belt and the geological events preserved within the Grenville Province.

scholarly journals Thermophysical Features of the Rümker Region in Northern Oceanus Procellarum: Insights from CE-2 CELMS Data

2020 ◽  
Vol 12 (19) ◽  
pp. 3272
Author(s):  
Zhiguo Meng ◽  
Jietao Lei ◽  
Yuqi Qian ◽  
Long Xiao ◽  
James W. Head ◽  
...  
Keyword(s):  
Brightness Temperature ◽  
Single Unit ◽  
Thermal Evolution ◽  
Microwave Radiometer ◽  
Landing Site ◽  
Age Dating ◽  
The Moon ◽  
Landing Sites ◽  
Geological Boundaries ◽  
Scientific Value

The Rümker region is located in the northern Oceanus Procellarum, which has been selected as the landing and sampling region for China’s Chang’e-5 (CE-5) mission. The thermophysical features of the mare units are studied in detail using the brightness temperature (TB) maps (TB, normalized TB, TB difference) derived from the CE-2 microwave radiometer data. The previously interpreted geological boundaries of the Rümker region are revisited in this study according to their TB behaviors: IR1, IR2, and IR3 Rümker plateau units are combined into one single unit (IR); and a hidden unit is found on the Mons Rümker; Mare basaltic units Im1 and Em1 are combined into Em1; and Em2 is more likely the extending of Im2. Each of the previous proposed landing sites and their scientific value are summarized and reevaluated. Based on this, four landing sites are recommended in order to maximize the scientific outcome of the CE-5 mission. We suggest that the Eratosthenian-aged Em4 and Em1 units as the top priority landing site for the CE-5 mission; the age-dating results will provide important clues concerning the thermal evolution of the Moon.

Structural characterization of Zn–In–Se thin films

2017 ◽  
Vol 31 (05) ◽  
pp. 1750043 ◽  
Author(s):  
H. H. Güllü ◽  
M. Parlak
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Film Surface ◽  
Compositional Analysis ◽  
Surface Characteristics ◽  
Thermal Evaporation Method ◽  
Near Surface ◽  
X Ray ◽  
Force Microscopy ◽  
Thin Film Surface

In this study, structural properties of the Zn–In–Se (ZIS) thin films deposited by thermal evaporation method were investigated. The as-grown and annealed ZIS films were found in polycrystalline structure with the main orientation in (112) direction. The compositional analysis of the films showed that they were in Zn-rich behavior and there was a slight change in the elemental contribution to the structure with annealing process. Raman analysis was carried out to determine the crystalline structure and the different vibration modes of ZIS thin films. According to these measurements, the highest Raman intensity was in the LO mode which was directly proportional to the crystallinity of the samples. The atomic force microscopy (AFM) analyses were done in order to obtain detailed information about the morphology of the thin film surface. The surface of the films was observed as nearly-smooth and uniform in as-grown and annealed forms. X-ray photoelectron spectroscopy (XPS) measurements were analyzed to get detailed information about surface and near-surface characteristics of the films. The results from the surface and depth compositional analyses of the films showed quite good agreement with the energy dispersive X-ray spectroscopy (EDS) analysis.

Compositional Analysis of III-V Interface Lattice Images

1980 ◽  
Vol 38 ◽  
pp. 318-319
Author(s):  
A. Olsen ◽  
J.C.H. Spence ◽  
P. Petroff
Keyword(s):  
Crystal Structure ◽  
Image Matching ◽  
Compositional Analysis ◽  
Depth Of Field ◽  
Limit Set ◽  
High Contrast ◽  
Resolution Limit ◽  
Fourier Image ◽  
Lattice Images ◽  
True Structure

Since the point resolution of the JEOL 200CX electron microscope is up = 2.6Å it is not possible to obtain a true structure image of any of the III-V or elemental semiconductors with this machine. Since the information resolution limit set by electronic instability (1) u0 = (2/πλΔ)½ = 1.4Å for Δ = 50Å, it is however possible to obtain, by choice of focus and thickness, clear lattice images both resembling (see figure 2(b)), and not resembling, the true crystal structure (see (2) for an example of a Fourier image which is structurally incorrect). The crucial difficulty in using the information between Up and u0 is the fractional accuracy with which Af and Cs must be determined, and these accuracies Δff/4Δf = (2λu2Δf)-1 and ΔCS/CS = (λ3u4Cs)-1 (for a π/4 phase change, Δff the Fourier image period) are strongly dependent on spatial frequency u. Note that ΔCs(up)/Cs ≈ 10%, independent of CS and λ. Note also that the number n of identical high contrast spurious Fourier images within the depth of field Δz = (αu)-1 (α beam divergence) decreases with increasing high voltage, since n = 2Δz/Δff = θ/α = λu/α (θ the scattering angle). Thus image matching becomes easier in semiconductors at higher voltage because there are fewer high contrast identical images in any focal series.

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