A Stand-Off Laser-Induced Breakdown Spectroscopy (LIBS) System Applicable for Martian Rocks Studies

Laser-induced breakdown spectroscopy (LIBS) is a valuable tool for evaluating the geochemical characteristics of Martian rocks and was applied in the Tianwen-1 Mars exploration mission with the payload called Mars Surface Composition Detection Package (MarSCoDe). In this work, we developed a laboratory standoff LIBS system combined with a Martian simulation chamber to examine the geochemical characteristics of igneous rocks, with the intention to provide a reference and a basis for the analysis of LIBS data acquired by MarSCoDe. Fifteen igneous geological standards are selected for a preliminary LIBS spectroscopic study. Three multivariate analysis methods were applied to characterize the geochemical features of igneous standards. First, quantitative analysis was done with Partial Least Squares (PLS) and Least Absolute Shrinkage and Selection (LASSO), where the major element compositions of these samples (SiO2, Al2O3, T Fe2O3, MgO, CaO, K2O, Na2O, and TiO2) were derived. The predicted concentrations ((Fe2O3 + MgO)/SiO2, Fe2O3/MgO, Al2O3/SiO2, and (Na2O + K2O)/Al2O3) were used to identify the geochemical characteristics of igneous rocks. Also, PCA, an unsupervised multivariate method was tested to directly identify the igneous rock lithology with no prior quantification. Higher correlation (0.82–0.88) are obtained using Principal Component Analysis (PCA) scores than using predicted elemental ratios derived by PLS and LASSO, indicating that PCA is better suited to identify igneous rock lithology than via quantitative concentrations. This preliminary study, using this LIBS system, provides suitable methods for the elemental prediction and geochemical identification of martian rocks, and we will use extended geologic standards and continue to build a robust LIBS spectral library for MarSCoDe based on this LIBS system in the future.

Geologi Situs Benteng Saksi Dan Kuripan Saka, Kabupaten Lampung Selatan

The sites of Benteng Saksi and Kuripan Saka are the center of settlement or the capital of Keratuan Darah Putih. The research was conducted in Kuripan Village, Penengahan District, South Lampung Regency. The research objective was to determine the factors causing the sites of Benteng Saksi and Kuripan Saka suitable for settlements. The method used is a field survey and interpretation of geological map data. The results of field observations and mapping showed that the areas of the sites of Benteng Saksi and Kuripan Saka were included in the morphological unit of undulating plains with an average height of 50 m above sea level consisting of tertiary-quaternary and alluvial volcanoclastic deposits. The rock lithology found was Breccia Rocks from the eruption of Rajabasa Volcano and Tufan Sandstones. Based on the analysis of basic physical aspects of the area such as the physical characteristics of the rocks, morphological conditions, availability of water sources, and disaster factors in the area of Benteng Saksi and Kuripan Saka sites, it does not indicate any problems in terms of the basic physical aspects of the area.

UAV (Unmanned Aerial Vehicle) for Landslide Analysis Case Study in Grenggeng Village, Kebumen District, Central Java

Remote sensing technology has developed rapidly; one of them is data acquisition techniques using UAV (Unmanned Aerial Vehicle). With high-resolution aerial photographs, an unmanned aerial vehicle (UAV) can be a flexible, cost-effective, and accurate monitoring of landslide technique. This research aimed to determine and test the utilization of unmanned aerial vehicles (UAVs) in congested areas. Data was collected at Grenggeng Village, Kebumen Regency, using unmanned aerial vehicles cruising altitude of 90 – 110 meters above ground level and a spatial resolution of 5 – 10 cm over a 0.200 km2 area. In November 2020, the research site will be a landslide area with similar rock lithology to the Halang Formation’s sandstone and claystone layers. Direct field observations revealed the geological structures involved and the rock lithology that produced the slip field, seepage, and the sorts of vegetation that the community had planted. According to aerial photography data, the relief appears to be a straight-line pattern in the direction of the geological structure, the slope of the layers, and different vegetation. Aerial photography using UAV can also be used to carry out rehabilitation and reconstruction techniques.

Slope Stability Analysis Based on Safety Factors on Slope CV. Mutiara Timur in Klampok Village, Tongas District, Probolinggo Regency

CV. Mutiara Timur is a company that is applying for a mining business permit for sirtu commodities in Klampok Village, Tongas District, Probolinggo Regency. The planned mining system is open pit mining using the quarry method. From the results of research in the field obtained rock lithology in the form of topsoil, gravel and sand. Where in the slope design later, the topsoil will be peeled off first. The purpose of slope stability analysis is to determine the geometry of the slope by taking into account the safety factor in order to create safe working conditions. Slope stability analysis on CV. Mutiara Timur using the Bishop method using the Slide v6.0 software. Based on the analysis carried out, the recommendation for slope geometry on a single slope is 4 meters high with a slope of 600 so that the no-load safety factor is 1.350 and the safety factor with load is 1.267. In addition, the slope geometry is obtained on the overall slope, which is a total height of 21 meters with a slope of 380 so that the no-load safety factor is 1.243 and the safety factor with the load is 1.239.

Organic Matter of Domanik Deposits of the Timan–Pechora Basin: the Oil Window Conditions

—A comprehensive study of Domanik deposits of the Timan–Pechora Basin has been carried out. The examined composition of hydrocarbon biomarkers, chemical structure of kerogen, carbon isotope composition, and rock lithology, the Rock-Eval pyrolysis data, and the contents of bitumen and Corg in the rocks give an insight into the geochemical processes in the oil window in the Domanik deposits, which took place at Tmax = 435–450 °C. The bitumen coefficient βCB is maximum in this temperature interval, reaching 30%. The obtained data on the distribution of polycyclic biomarkers in the Domanik rocks and the bitumen and Rock-Eval pyrolysis data allowed determining the boundary values of biomarker maturity coefficients in the study of the maturation of organic matter of the rocks. The carbon isotope composition of bitumen fractions in the Domanik rocks is considered, and the bimodal distribution of the δ13C values of the bitumen is shown.

Multiple Influence Factor Sensitivity Analysis and Height Prediction of Water-Conducting Fracture Zone

To explore the influence law and sensitivity of various factors on the height of the water-conducting fracture zone, and further predict the development height of the water-conducting fracture zone, taking the field survey and collected actual measured data as the research foundation, establishing mathematical model, regression analysis, and field measurement were adopted comprehensively. Based on the Data Processing System (DPS), influence factors of the development height of the water-conducting fracture zone were analyzed. By introducing sensitivity coefficient, a sensitivity quantification mathematical model was established, and sensitivity ranking was obtained. The regression relationship between each factor and the height of the water-conducting fracture zone was obtained by single factor analysis. Based on this, the prediction formula was proposed and successfully used in the field practice. Results show that the sensitivity coefficient of mining thickness, ratio coefficient of hard rock lithology, mining depth, and length of working face was 0.75, 0.69, 0.66, and 0.58, respectively. The dispersion degree of working face length and mining depth was greater than that of ratio coefficient of hard rock lithology and mining thickness. To some extent, it also reflects that the sensitivity of working face length and mining depth to the height of the water-conducting fracture zone was the weakest, which was consistent with the previous conclusions. Using the multiple regression mathematical model, a nonlinear statistical relationship between the height of the water-conducting fracture zone and ratio coefficient of hard rock lithology, mining thickness, working face length, and mining depth was obtained. This research provides some scientific basis and guidance for safe and efficient underwater mining.

An application of field-based photogrammetry as a virtual outcrop building target: a key example from Santorini’s northern caldera wall, Greece

<p>The application of photogrammetry to volcanic areas is usually made using UAVs for collecting pictures aimed at producing high-resolution orthomosaic and digital surface models. In the present work, instead, we use a boat-camera-based photogrammetry approach, as a tool for orthomosaic, digital surface modelling and virtual outcrop production at an almost vertical 300-m-high geological feature: the northern caldera wall of Santorini. This is a geological structure of great interest, where many tens of dykes crop out within a heterogeneous host rock made of sequences of effusive and explosive volcanic deposits. Some active and inactive faults also dissect the caldera wall. Thus, the study area is almost inaccessible for classic field surveys due to challenging logistic conditions and landslide hazard.</p><p>We used a 20 MPX camera run by an operator who collected a total of 887 pictures almost continuously, orthogonal to the ground and opposite to the target, during a 5.5-km-long boat survey. We performed the study along the northern caldera wall, at a constant boat velocity and at a distance from the coast/caldera wall that varied between 35.8 m and 296.5 m. The outcomes of the photogrammetry application include: 1) a high-resolution 3D model of the study area, 2) a high-resolution virtual outcrop for two selected parts of the caldera, 3) qualitative and quantitative structural data (dyke attitude, thickness, cross-cutting relationships, host rock lithology) along the vertical caldera cliff. Our method represents a new approach for 3D outcrop building for research under extreme logistic conditions.</p>

Analisis Kelayakan Pemukiman Menggunakan Metode Analytic Hierarchy Process (AHP) Kecamatan Kuta Baro, Kabupaten Aceh Besar

The use of land resources for settlements is generally determined by the capability of the land or the appropriateness of the land. Residential area planning must consider the risk of a disaster because it will have an impact on material and physical losses. Administratively, the research area is located in the north of Kuta Baro Sub-District, Aceh Besar District, Aceh Province with a research area of about 12 km2. The research location which is close to the Seulawah Agam volcano will cause potential impacts of disasters such as volcanic eruption and landslide. The purpose of analyzing settlement land use using the Analytic Hierarchy Process (AHP) method in this study is to determine and analyze the feasibility of residential land at the research location. The parameters used in the land use analysis consist of 5 parameters including rock lithology, geomorphological conditions, slope, soil type, and rainfall. The results obtained in this study were 3 (three) classes of land use feasibility zones, namely the feasible zone, the less feasible zone, and the unfeasible zone. Analysis of land use suitability based on the feasible zone for settlements in Kuta Baro District with lowland geomorphology (0 - 8% slope level), rock lithology in the form of silt deposits, low rainfall, and alluvium soil types which have a very low level of erosion.

Experimental Evaluation of Multiple Frost Heaving Parameters for Preflawed Granite in Beizhan Iron Mining, Xinjiang, China

Ice-driven mechanical weathering in cold regions is considered a main factor impacting the stability of rock mass. In this work, the response surface method (RSM) was employed to evaluate and optimize the multiple frost heaving parameters to seek the maximum frost heaving force (FHF), in combination with experimental modeling based on a specially designed frost heaving force measurement system. Three kinds of rocks were prepared with parallel flaws in it having different flaw width, length, and cementation type, and these factors were used to fit an optimal response of the maximum FHF. The experimental results reveal five distinguished stages from the frost heaving force curve, and they are inoculation stage, explosive stage, decline to steady stage, recovery stage, and sudden drop stage. The sensitivity analysis reveals the influential order of the considered factors to peak FHF, which is the rock lithology, flaw width, flaw cement type, and flaw length. For low-porosity hard rock, increasing flaw width, flaw length, and flaw cement strength can improve the probability of frost heaving failure. It is suggested that rock lithology determines the water migration ability and influences the water-ice phase transformation a lot.

IDENTIFICATION OF FAULT CONTINUITY AND HOT WATER RESERVOIR USE SCHLUMBERGER CONFIGURATION RESISTIVITY METHOD IN CANGAR

Research that uses the Schlumberger configuration resistivity method had been conducted in Cangar. The purpose of this study is to identify cracks/faults and potential hot springs use resistivity well analysis and correlate it with rock lithology in Cangar, East Java. Data acquisition is carried out using 3 tracks with 10 sounding points. The space between points is 50 meters. The rock resistivity values obtained were 9945 Ωm, 7360 Ωm, and 5573 Ωm which were thought to be breccia layers and functioned as hot springs. This estimation is strengthened by the existence of a layer of breccia-andesite because this layer is very good as a water reservoir. In addition, based on the lateral cross-section on lane 1, there was a decrease in boulder-sized breccia-andesite layers; this decrease was the production of faults.