Lithological Types Research Articles

Influence of stress and geology on the most prone time of rockburst in drilling and blasting tunnel: 25 tunnel cases

Rockburst exhibits different occurrence time characteristics during drilling and blasting in tunnel excavation, posing challenges to the safe and efficient construction of tunnels. In this study, 25 tunnels with rockburst hazards were examined. By employing the clustering method, we analyzed the characteristics of the most prone time (MPT) for rockburst. Furthermore, we investigated the contribution degree and influence mechanism of stress and geological factors related to the MPT of rockburst. The outcomes revealed that distinct tunnels exhibit diverse rockburst-prone times, leading to varying hazards and losses. The higher the maximum principal stress and the angle between it and the tunnel axis, the earlier the rockburst occurs. Moreover, the MPT of rockburst is influenced by both lithological types, macro and micro rock structures. When the joint intersects with the maximum principal stress at a small angle, rockburst occurs earlier. The stress direction, UCS, attitude of the dominant joint, and stress magnitude stand out as the principal controlling factors. The findings of this research can serve as a basis for assessing the MPT of tunnel rockburst, timing rockburst risk control measures, and selecting appropriate mitigation strategies.

Potential Controlling Factors and Landslide Susceptibility Features of the 2022 Ms 6.8 Luding Earthquake

On 5 September 2022, a Ms 6.8 earthquake struck Luding County, Ganzi Tibetan Autonomous Prefecture, Sichuan Province, China. This seismic event triggered over 16,000 landslides and caused serious casualties and infrastructure damages. The aim of this study is to perform the detailed landslides susceptibility mapping associated with this event based on an updated landslide inventory and logistic regression (LR) modeling. Firstly, we quantitatively assessed the importance of different controlling factors using the Jackknife and single-variable methods for modeling landslide occurrence. Subsequently, four landslide susceptibility assessment models were developed based on the LR model, and we evaluated the accuracy of the landslide susceptibility mappings using Receiver Operating Characteristic (ROC) curves and statistical measures. The results show that ground motion has the greatest influence on landslides in the entire study area, followed by elevation, while distance to rivers and topographic relief have little influence on the distribution of landslides. Compared to the NEE plate, PGA has a greater impact on landslides in the SWW plate. Moreover, the AUC value of the SWW plate significantly decreases for lithological types and aspect, indicating a more pronounced lithological control over landslides in the SWW plate. We attribute this phenomenon primarily to the occurrence of numerous landslides in Permian basalt and tuff in the SWW plate. Otherwise, the susceptibility results based on four models indicate that high-susceptibility areas predicted by different models are distributed along both sides of seismogenic faults and the Dadu Rivers. Landslide data have a significant impact on the model prediction results, and the model prediction accuracy based on the landslide data of the SWW plate is higher.

A Novel Sample Generation Method for Deep Learning Lithological Mapping with Airborne TASI Hyperspectral Data in Northern Liuyuan, Gansu, China

High-resolution and thermal infrared hyperspectral data acquired from the Thermal Infrared Airborne Spectrographic Imager (TASI) have been recognized as efficient tools in geology, demonstrating significant potential for rock discernment. Deep learning (DL), as an advanced technology, has driven substantial advancements in lithological mapping by automatically extracting high-level semantic features from images to enhance recognition accuracy. However, gathering sufficient high-quality lithological samples for model training is challenging in many scenarios, posing limitations for data-driven DL approaches. Moreover, existing sample collection approaches are plagued by limited verifiability, subjective bias, and variation in the spectra of the same class at different locations. To tackle these challenges, a novel sample generation method called multi-lithology spectra sample selection (MLS3) is first employed. This method involves multiple steps: multiple spectra extraction, spectra combination and optimization, lithological type identification, and sample selection. In this study, the TASI hyperspectral data collected from the Liuyuan area in Gansu Province, China, were used as experimental data. Samples generated based on MLS3 were fed into five typical DL models, including two-dimensional convolutional neural network (2D-CNN), hybrid spectral CNN (HybridSN), multiscale residual network (MSRN), spectral-spatial residual network (SSRN), and spectral partitioning residual network (SPRN) for lithological mapping. Among these models, the accuracy of the SPRN reaches 84.03%, outperforming the other algorithms. Furthermore, MLS3 demonstrates superior performance, achieving an overall accuracy of 2.25–6.96% higher than other sample collection methods when SPRN is used as the DL framework. In general, MLS3 enables both the quantity and quality of samples, providing inspiration for the application of DL to hyperspectral lithological mapping.

Regional coastal cliff classification: Application to the cantabrian coast, Spain

The retreat of coastal cliffs is a natural process that occurs due to the interaction of different forcings that can be marine and atmospheric, and conditioned by the lithological properties of the rock material. Several attempts have been done at different scales to quantify and rank the various parameters that influence erosion rates, most of them agreeing that cliff retreat is governed by the lithological properties of the cliffs. Although, due to the large number of parameters involved there is not a clear consensus.The present study aims to characterize the cliffs along the Cantabrian coast by using an unsupervised classification of their physical and lithological characteristics, and by analyzing their retreat behavior. The proposed methodology is scalable to larger coastal areas. The study found that Cantabrian coastal cliffs have a low mean retreat rate of 0.042 m/year, with a maximum retreat rate of up to 0.4 m/year in two locations. Nine distinct groups of cliff behavior have been found, with only two of them presenting high erosional records, which are controlled by lithological features. Cliffs with the highest erosion rates are composed of alternating lithologies and more erodible materials. The results suggest that the factors most influencing erosive retreat in cliffs are the type of lithology and the alternation of different lithologies.

Differential characteristics of lithological assemblages and gas-bearing of the Permian Longtan Formation mudstone in well L3, southeastern Sichuan Basin

As the main reservoir of coalbed gas in southeastern Sichuan, the mudstone of the Permian Longtan Formation has been drilled to obtain industrial gas, but the level of exploration and development is low. The researches on the types of lithological assemblages, reservoir characteristics, and gas-bearing properties are poor, which limits the evaluation and selection of the sweet point area for the marine-continental transitional shale gas. In this paper, by comparing the differential of different lithological distribution in the well L3, multiple discriminant functions and logging interpretation models for different lithology are established to determine the classification criteria of lithological assemblage types of shale formations. Based on the experimental results of high-temperature and high-pressure isothermal adsorption, the reservoir space distribution and gas-bearing characteristics of mudstone in different lithological assemblages are compared and analyzed. It is indicated that the four lithological assemblage types are found in the Permian Longtan Formation, including thick mudstone with the interlayer of coalbed (Type I), rich mudstone with the interlayer of sandstone and thin coalbed (Type II), sandstone interbedded with mudstone with the interlayer of coalbed (Type III), and limestone interbedded with sandstone with the interlayer of mudstone (Type IV), which are superimposed with each other. The different pore structure characteristics of mudstone in different lithological assemblages is the main influencing factor of differential gas-bearing property. The dominant lithological assemblages are Type I and Type II. Coalbed and carbonaceous mudstone are the source rock and primary storage space of adsorbed gas. Moreover, with low porosity and permeability, high breakthrough pressure and the strong sealing capacity of regional mudstone, it is easy to form the “microtrap” to store the natural gas. The sealing capacity of mudstone provides a favorable condition for gas preserve. Under the dynamic condition of hydrocarbon generation, the pressure storage box is formed, accompanied with the fine reservoir spaces and gas-bearing contents.

Sinkholes Mapping in Tanjungsari, Gunung Kidul Regency, Yogyakarta: A Preliminary Data for the Assessment of Sinkhole’s Susceptibility

Abstract Tanjungsari district is located in Gunung Kidul Regency, Yogyakarta, known as the karst region where the dissolution process has taken place and caused some sinkhole occurrence. However, there is no any study that carry out the characteristic and the specific number of sinkholes presence in this area yet. Therefore, this study aims to create a sinkhole map in the study area with the observation of its physical characteristics based on some important data such as lithological data, geomorphological feature, existed sinkhole location as well as its physical characteristic that were collected by field observation and the secondary data evaluation. Limestone is the only lithology type was found in the study area and it is likely to be influenced by the dissolution process. Furthermore, there are more than 20 sinkholes were found with approximate 1m to 80 m in diameter and a few meters onward in depth. Some of them formed like a shallow bowl and some are vertical wall. Most of them associated with the gentle slope and the soil cover area. The results from the study will serve as important information for further detail study such as sinkhole’s susceptibility mapping.

Geology of the Kebasen Paleovolcano in Banyumas Regency, Central Java Province, Indonesia

Abstract The new interpretation on geology of Kebasen district in Central Java, Indonesia which is located in the middle parts of Sunda Arc indicates the existence of a paleovolcano. This conclusion is achieved through 1:25,000 geological mapping with a focus on volcanic facies, characterization of lithology types, mineralogy, and fossil analysis, to clarify its volcanic history and paleo-environment. Laboratory analysis works on representative rock samples are done using petrography and fossil identification on calcareous sedimentary members. Our research results conclude that Kebasen paleovolcano was a composite volcano with a diameter of about 8 km, elongated in NW-SE orientation, with Kebasen city located at the SW rim of the old volcanic edifice. The volcanic history and resulting volcanic rocks consisted of two contrasting volcanic stages. The first one was explosive caldera-forming eruptions that produced thick and partly welded pyroclastic rocks, dominated by pyroclastic breccia at the lower parts and finer tuff members at the upper parts. After caldera-forming eruptions, volcanic activity was followed by effusive eruptions of basaltic to andesitic lavas that covered the caldera floor. The lavas have abundant pillow structures indicating a submarine environment, intermediate to basaltic composition, and porphyritic texture, with plagioclase and pyroxene as the most abundant phenocryst minerals. Available rock geochemistry data demonstrate that lavas have mafic to intermediate compositions, with magma affinity at the transition of calc-alkaline to tholeiitic series. Results of geomorphological and lithology association analysis conclude that the research area was part of the central to distal facies of a paleovolcano complex, with the paleo depositional environment in the open marine environment. The results of fossil analysis on calcareous sedimentary rocks between volcanic layers indicate that the age of volcanism was Early Pliocene (N18) with the paleobathymetry transitioning from upper-middle bathyal to outer–middle neritic, which were parts of the continental margin. It is concluded that Kebasen paleovolcano is a newly identified submarine caldera-type Pliocene volcano within the middle parts of the Sunda Arc in Central Java, Indonesia.

Geology and Geochemistry of Aberma and Its Environ Sheet 54se Gusau, Zamfara State, Nigeria

The study area falls within the northwestern part of Nigeria and is underlain by crystalline rocks of the Basement Complex. Field mapping in Aberma and its environs were carried out using topographical map sheet of 54 SE Gusau on a scale 1: 25,000 with an area extends of about 30.8052km2. This field work was carried out using traverse method in conjunction with field equipment such as compass/clinometers, geologic hammer, sample bag and global positioning system. This study however, aims at producing a detail geological map, including the various rock geochemistry and petrography of the study area. The area is underlain by two major lithological rock type which is mica schist and granite gneiss. The granite gneiss is strongly foliated, caused by high temperature and pressure and the minerals observed in plane polarized light include quartz, orthoclase, plagioclase, muscovite, opaque mineral and biotite. The mica schists in the study area are mostly weathered in ditches below the ground surface, the rock is moderately weathered and show schistocyte. The minerals observed in plane polarized light include quartz and muscovite. The dominant structures observed include; joints, Quartz veins, foliation and pegmatite dyke. Structural analysis shows that the rocks have been affected by the Pan African orogeny with the joint’s orientation trending dominantly NNE-SSW and Quartz vein trending in somewhat E-W direction. The microscopic studies revealed that the mineralogical composition of the rocks types of the study area contain varying percentages of quartz, muscovite, plagioclase, orthoclase, opaque mineral and biotite as the major minerals. The geochemical analysis revealed the major and minor elemental distribution of the rock types of the study area. The chemical assay revealed that the granite gneiss and mica schist rock type of the study area are super-saturated with respect to silica, silica (SiO<sub>2</sub>) is the most abundant oxide with an average value of 78.12% in the rock sample. This implies that the rock analyzed is acidic in nature and must have formed from crystallization of an acidic magma because the silica content being greater than 65%.

Groundwater identification using geophysical tools and its implications for the stability of slopes in an open pit mine

The open pit mining development begins with the opening of pits with the rock mass excavation and formation of slopes and berms for ore exploration. Knowledge about the geological conditions represents an important step in this process, since rock masses generally have heterogeneous characteristics and the presence of discon- tinuities can become an aggravating factor in the safety of operations. The characterization and classification of these discontinuities, as well as the identification of the groundwater in the rock mass, has a great importance to ensure the safety of operations during the mine's production process, in addition to ensure the effectiveness of its decommissioning process. The use of DC resistivity geophysical method has been increasing to characterization and identification lithological types and presence of water, since it is a non-invasive research tool with fast ability to obtain data. DC resistivity together with visual investigation methods, such as obtaining the discontinuities orientation and their alteration characteristics, provides important information for the characterization of the rock mass. Given this importance, the present work aimed to use DC resistivity to identify the presence of water and its correlation with lithology and rock mass structure in order to identify how these variables influence the occurrence of ruptures. To this end, two-dimensional resistivity sections were designed and related to visual inspection data and kinematic analyzes obtained from structural data of the rock mass. The integration of these results indicated that the ruptures present in the investigated mine slopes are related to zones whose predominant lithology is volcanic breccia with the presence of water in the subsurface. These ruptures compromise the stability of the slopes and consequently make the decommissioning mine process difficult.

Coupling of Paleosedimentary Environment and Lithofacies: Implications for Shale Oil Enrichment in the Lianggaoshan Formation, Northeastern Sichuan Basin, China.

The sedimentary environment is paramount in dictating depositional processes, ecological settings, and hydrodynamic conditions, all of which are pivotal to the aggregation of organic-rich sediments. A synergistic interplay is observed among the paleosedimentary environment, lithofacies, and enrichment of shale oil. Utilizing an analysis of elemental geochemistry and organic geochemical parameters-such as total organic carbon (TOC) content-this study endeavors to identify the predominant factors that govern the enrichment of organic matter (OM). It reconstructs the evolutionary trajectory of the paleosedimentary environment and introduces a dynamic model for shale oil enrichment within the Jurassic Lianggaoshan Formation of the Sichuan Basin. The results indicate that the Lianggaoshan Formation shale can be categorized into five lithological types, including high TOC felsic-rich shale (A), moderate TOC felsic-rich shale (B), moderate TOC felsic-rich mudstone (C), low TOC felsic-rich shale (D), and low TOC felsic-rich mudstone (E), and high TOC felsic-rich shale has the highest TOC and oil content. The shales of the Lianggaoshan Formation were deposited in an environment characterized by abundant terrestrial input, humid climate, freshwater conditions, reduced oxygen levels, and thriving primary productivity. OM enrichment is mainly controlled by the combination of a humid paleoclimate, high primary productivity, and other factors. The paleoenvironment deposited by lithofacies A coincides with the paleoenvironment conducive to OM enrichment, which makes lithofacies A become the dominant lithofacies for shale oil enrichment. Additionally, the sedimentary environment evolution characteristics and shale oil enrichment model of the Lianggaoshan Formation were established based on geochemical parameters. The paleosedimentary environment of the Lianggaoshan Formation from bottom to top is more and more unfavorable. The No.1 submember of the Lianggaoshan Formation is the most potential shale submember for shale oil exploration due to the paleosedimentary environment that promoted the deposition of lithofacies A and OM enrichment.

Landslide susceptibility assessment using different rainfall event-based landslide inventories: advantages and limitations

AbstractThe present work aims to evaluate potential sources of uncertainty associated with rainfall-triggered event-based landslide inventories within the framework of landslide susceptibility assessment. Therefore, this study addresses the following questions: (i) How representative is an event-based landslide inventory map of the total landslide activity and distribution in a study area?; (ii) How reliable is an event-based landslide susceptibility map?; (iii) How appropriate is an event-based landslide inventory map for independently validating a landslide susceptibility map? To address these questions, two independent and contrasting rainfall event-based landslide inventories were used, together with a historical landslide inventory, to assess landslide susceptibility for different types of landslides in a study area located north of Lisbon, Portugal. The results revealed the following findings: (i) contrasting rainfall critical conditions for failure can trigger similar landslide types, although they may vary in size and be spatially constrained by different predisposing conditions, particularly lithology and soil type; (ii) landslide susceptibility models using event-based landslide inventories are not reliable in the study area, regardless of the landslide inventory map used for training and validation; and (iii) complementary sources of uncertainty results from using incomplete historical landslide inventories to assess landslide susceptibility and non-totally independent landslide inventories for modeling validation. The present study enhances the understanding of regional landslide susceptibility patterns based on contrasting rainfall-trigger conditions, providing valuable information to minimize exposure; to design regional landslide early warning systems for specific rainfall-trigger landslide events; and to improve the response and preparedness of civil protection services.

Utilizing logs to identify complex lithology of tight marl reservoir in the Leikoupo Formation 32 Submember (T2l32) of the Sichuan Basin, China

Recent exploration has revealed that the Middle Triassic Leikoupo Formation 32 Submember (T2l32) in the Sichuan Basin contains unconventional marl reservoirs with significant natural gas potential. Due to limited cores, old wells, and conventional logs, however, the lithological understanding of T2l32 is incomplete and relies solely on inaccurate mud logs. This lack of lithological foundation challenges geology and petroleum research. To identify complex lithology, this paper presents a double-hierarchical workflow to identify seven types of lithology using logs. The first order distinguishes salt, anhydrite, and marl, while the second order further subdivides marl into anhydrite marl, argillaceous limestone, shaly limestone, and limy shale. Different rocks’ logging response characteristics are summarized based on quantity-limited cores and micro-resistivity imaging logs. Lithological identification of 2D and 3D plots is established using sensitive GR, DEN, and RT. Corresponding identification standards are built in two hierarchies. According to these standards, the lithology of T2l32 is identified in a total of 119 wells. Finally, the lithological characteristics of vertical, horizontal, and plane are discussed in the research area. The research results may aid in comprehending the entire lithological characteristics of the complex marl reservoir in T2l32 of the Sichuan Basin. It would help the exploration potential of petroleum systems in turn.

Revisiting the rocks discovers turbidites and a new exploration play in the Penola Trough, Otway Basin, South Australia

As part of an integrated geological, geochemical, and geophysical study, conventionally cored intervals from the lower-most stratigraphic section of the onshore South Australian part of the Penola Trough, Otway Basin have been reviewed and reinterpreted. Three conventionally cored wells; Bungaloo-1, Jolly-1ST1 and Sawpit-2, were described using a quick-look approach to determine gross lithological and sedimentological information. Seven lithology types were observed: clay-siltstone with horizontal lamination, diamictite (claystone with horizontal lamination and dropstones), clay-siltstone with massive-horizontal lamination, silt-sandstone with horizontal lamination, sandstone with ripple lamination, sandstone with parallel lamination and sandstone with massive bedding ± rip-up clasts. The first two lithologies are interpreted as representing deposition in a cold climate, profundal-lacustrine depositional environment. The first, containing interpreted varves is the most distal and the second, containing dropstones indicates relatively colder freeze/thaw conditions. The last five lithologies are interpreted as lacustrine turbidite depositional environments, specifically Bouma sequences Te, Td, Tc, Tb and Ta, respectively. Seismic facies interpretation has identified canyon-like and mound features and interpreted them as slope-feeder channels and fan/s respectively, at and away from well control. This rock-based turbidite interpretation provides an alternative to the current alluvial channel/crevasse splay/floodplain lake model for reservoir deposition and as such presents a new exploration play. Further the reservoirs’ immediate lateral association with gas/oil-prone source rocks and seals in the clay-rich lithologies potentially provide for stratigraphic trapping in addition to the previously targeted fault-controlled structural traps.

An intelligent lithology recognition system for continental shale by using digital coring images and convolutional neural networks

Lithology identification is a critical component of reservoir evaluation and hydrocarbon development. However, the continental shale rocks, characterized by complex lithologies and developed laminations, present new challenges to traditional lithology identification techniques. In this study, we develop a centimeter-level intelligent identification system for continental shale lithology, leveraging digital image preprocessing and deep learning methods. Specifically, we construct a dataset from 400 m of drilling cores, encompassing 24 types of lithology and 152 lithological transitions. The downsampling and oversampling methods are employed to balance the dataset. The digital image denoising and restoration techniques are then utilized to enhance rock image features. Different neural network models are examined to obtain the optimum predictive results. The results indicate that data balancing improves the TOP1 and TOP5 accuracies by 10% and 5%, respectively. Gaussian low-pass filter denoising, in comparison to other methods, increases the TOP1 and TOP5 accuracies by 2%, establishing it as the superior denoising technique for lithology recognition. Considering both computational efficiency and prediction accuracy, EfficientNet emerges as the most effective model for continental shale image recognition. The optimized model attains up to 60% TOP1 and 95% TOP5 across 22 categories in drilling core samples. This study delves into the intelligent identification of macroscopic drilling core images of continental shale, and the findings can offer technical support for the interpretation and evaluation of continental shale reservoirs.

Unveiling novel APLIS model for identifying groundwater recharge zones in semi-arid regions: A case from Lebanon

The Bekaa Plain in Lebanon, is a major agricultural region known for its fertile soil and extensive crops cultivation using groundwater resources which is recently became under stress due to population growth, urbanization, and climate change. The main aim of this study is to investigate the rate of groundwater recharge (GwR) into this region using APLIS Model which principally depends on altitude, slope, lithology, infiltration, and soil type. Using GIS-based for a multicriteria mapping approach, in this study additional factors were added to the model, by incorporating rainfall rates, stream density, and fracture density. Results revealed various recharge potential area in the Bekaa Plain, with 52 % classified as high to very high GwR zones, equivalent to approximately 42.5 % of precipitated water, which is a testament to the exceptional capacity of the region to replenish groundwater aquifers. The geographic distribution of GwR categories primarily depends on altitude and lithological characteristics. The exceptional GwR potential of the Bekaa Plain holds immense promise for mitigating water scarcity, fostering agricultural productivity, and ensuring the socioeconomic well-being of communities reliant on groundwater resources.

Microfacies and mineralogical analyses of the late cretaceous carbonate rocks from The Central Benue Trough, Nigeria

The Cretaceous limestone facies from Yandev section in the central Benue Trough, Nigeria constitutes parts of the potential reservoirs and sources rocks for petroleum prospects in the basin. The central Benue Trough is the least studied basin among its contemporaries due to lack of subsurface data. Detailed mineralogical, facies analysis and diagenesis of these carbonate rocks in the basin have not received significant study. The aim of this study was to employed multifaceted methodology such as sedimentological, facies analysis petrographic and geochemical approaches which was lacking in previous research in the trough. The sedimentological analysis was done to evaluate fabrics grain sizes, and lithology types. For petrographic analysis, thin sections were prepared and examined under a petrographic microscope and categorized according to Dunham's classification. Geochemical analysis involved X-ray fluorescence (XRF), X-ray diffraction (XRD), and scanning electron microscope - energy dispersive X-ray spectroscopy (SEM-EDX) techniques to unveil mineralogical, oxide, and elemental compositions. The sedimentological results revealed light to dark grey medium to fine-grained limestone facies with intercalation of dark grey shales and siltstones. The XRD mineralogy data, revealed calcite (60.00 - 64.10%), quartz (14.30 - 51.00%), albite (12.30 - 19.00%), and chlorite (6.30 - 8.10%). Microfacies results revealed distinct sandy bioclastic wackstone and sparitic intraclastic packstone, as well as micritic intraclastic wackestone and sparitic bioclastic packstone. SEM images highlighted the intricate composition, including elongated structures, whites and dark spots suggesting varying conditions of deposition. Elemental analysis through EDX emphasized significant proportions of carbon, oxygen, sodium, potassium, calcium, silicon, aluminum, iron, and magnesium. Based on sedimentological, biofacies, lithofacies and geochemical evidence we infer that the carbonate sediments were mainly deposited in a shallow marine depositional environment (inner to outer neritic).

Exploration history of the igneous reservoirs of the Rio Grande Valley (Mendoza), Neuquén Basin (Argentina)

Abstract Oil seeps related to igneous rocks in the Neuquén Basin have been known since pre-Hispanic times (sixteenth century) and have been explored in the southern Mendoza province since the late nineteenth century. In the 1980s, YPF (Yacimientos Petrolíferos Fiscales) began the exploration of igneous rocks as hydrocarbon reservoirs in the Río Grande Valley area. The possible productivity of these ‘unconventional’ reservoirs was recognized by studying outcrops and well data of sills and dykes emplaced in different formations of the fold and thrust belt of the northern Neuquén Basin. Mud-logging control and evaluations with drill stem tests (DST) were decisive to define these reservoirs as prospective. From petrographical reports on samples from outcrops and cores, six lithological types could be distinguished in the igneous units of this region. Recent works confirm that this volcanism belongs to two predominant cycles: from the late Oligocene to the Miocene (‘Molle’) and from the Middle to upper Miocene (‘Huincán’). Although in igneous reservoirs it is difficult to forecast the estimated ultimate recovery (EUR), sills that crosscut the source rocks of the Vaca Muerta and Agrio formations demonstrate surprisingly high production rates, although the number of wells for the complete development is always difficult to establish.

Subsurface Interpretation of the Panjang Fault Area, Lampung, Based on Geomagnetic Method

Research on the area along the Panjang Fault - Lampung, the area from the Teluk Betung to Tanjung Karang Barat area using the 19-T GSM PPM tool with base rover acquisition on 2 tracks 2 kilometers apart obtained 40 acquisition points with a spacing of 0.3 kilometers. This study aims to determine the type of lithology and subsurface rock structure by utilizing the susceptibility value of rocks from magnetic anomalies. In the process of processing magnetic anomaly data, upward continuation is carried out as high as 350 m which is intended to reduce the total anomaly with the upward anomaly results so that a residual anomaly is obtained. Next, make a 2D subsurface model on the incision A - B in the residual anomaly map. Based on the results of qualitative interpretation, the total magnetic anomaly of the research area illustrates positive to negative anomaly values with a tighter contour pattern that indicates the presence of a fault structure. While based on quantitative interpretation, the 2D modeling in incision A - B shows a susceptibility value of 0.100 cgs which can be identified as breccia tuff rock, a susceptibility value of 0.0391 cgs is thought to be rhyolitic tuff rock, pumice tuff rock, and sandstone tuff, and a susceptibility value of 0.150 cgs is a rock from the intrusion of Mount Betung in the form of andesite-basalt lava. In addition, rocks with a susceptibility value of 0.0024 cgs are metamorphic rocks. The correlation between 2D modeling and regional geology is seen in the research area, which is in the Tarahan Formation (Tpot), which is suspected to be a fault structure in the Bumi Waras area with a strike direction of NW - SE which is the course of geothermal manifestations or minerals.

Biogeochemical prospecting of metallic critical raw materials: soil to plant transfer in SW Ciudad Real Province, Spain

The soil–plant transfer of trace elements is a complex system in which many factors are involved such as the availability and bioavailability of elements in the soil, climate, pedological parameters, and the essential or toxic character of the elements. The present study proposes the evaluation of the use of multielement contents in vascular plants for prospecting ore deposits of trace elements of strategic interest for Europe. To accomplish this general goal, a study of the soil–plant transfer of major and trace elements using Quercus ilex as a study plant has been developed in the context of two geological domains with very different characteristics in geological terms and in the presence of ore deposits: the Almadén syncline for Hg and the Guadalmez syncline for Sb. The results have made it possible to differentiate geological domains not only in terms of individual elements, but also as a combination of major and trace elements using Factor Analysis. The bioconcentration factors have demonstrated the uptake of macronutrients and micronutrients in very high concentrations but these were barely dependent, or even independent of the concentrations in the soil, in addition to high values of this factor for Sb. The Factor Analysis allowed for the differentiation of geogenic elements from other linked to stibnite ore deposits (Sb, S, and Cu). This element (Sb) can be uptake by Quercus ilex via the root and from there translocating it to the leaves, showing a direct relation between concentrations in soil and plants. This finding opens the possibility of using Quercus ilex leaves for biogeochemical prospecting of geological domains or lithological types of interest to prospect for Sb deposits.

Prediction of CPTu static sounding parameters based on DPH dynamic probing heavy test on the example of “the Praski terrace” sands inWarsaw title

This paper attempts to relate the parameters obtained from CPTu static sounding and DPH dynamic test conducted in non-cohesive alluvial deposits of the Vistula River. The investigation was carried out in eight test stations located on the left bank of the Vistula River in Warsaw. The presented theses were based on the results of static CPTU and dynamic DPH tests obtained at 8 test stations. Additionally, in order to associate the obtained sounding results to the lithological type of the tested medium, drillings and grain size analyses were performed. The correlation of the different test methods stems from the need to identify and explain observed discrepancies against the background of different geological conditions, such as moisture content or grain size distribution. The comparative analysis of the parameters obtained from static and dynamic probing, is relevant to the alluvial sediments formed the lower over-flood terrace (called “the Praski terrace”) of Warsaw. Based on the comparison this paper proposes a correlation between the cone penetration resistance the sleeve friction and the number of blows, expressed by the functional relationship. Differences in the matching formulas were shown depending on the saturation of the tested sediments. Correlations were referred to a soil type, which enabled to specify the range of applicability of the proposed relationships. The results of the study were further used to show their diversity using statistical methods. This made it possible to assess the variability of the parameters of the non-cohesive soil, which forms a single lithogenetic unit.