Mud Pools Research Articles

Linking top and subsoil types, alteration and degassing processes at Rotokawa geothermal field, New Zealand

Surface geothermal expressions such as mud pools, fumaroles, mineral deposits, collapse pits, and hydrothermal eruption craters vary in scale and type over space and time. The evolution in space and time of these surficial thermal features strongly relates to alteration processes caused by hydrothermal fluids. The changes in the physical and mechanical properties of top and subsoils that can control fluid flow, degassing patterns, and occurrence of geothermal hazards remain understudied. The thermal area located south of the Rotokawa geothermal field (New Zealand) includes a variety of major natural surface thermal features and widespread sulphur deposits precipitated by acid–sulphate fluids in steam-heated zones. Decades of sulphur mining induced the formation of new thermal features. Such a setting represents an exemplary case study for investigating old and recently formed thermal features, soil characteristics, types and patterns of superposed hydrothermal alteration, and degassing processes. We combined field and laboratory methods to define groups of thermal features, soil types, and associated alteration. Their spatial distribution indicates that fluid circulation, alteration intensity, and degassing are strongly influenced by the local and regional geological and structural settings, as well as by mining activity. We found that at the water table level and within excavated areas, acidic fluids led to the deposition of mud deposits, sinters, and stromatolites around warm springs and mud pools. In the vadose, steam-heated portions, fluids generally leach and degrade the Taupo Pumice, resulting in broad unstable grounds and collapse structures, while extensive sulphur-encrusted grounds and sulphur-rich soils formed in excavated sites. In this framework, the degassing and fluid circulation within the top and subsoils are strongly affected by the dominant soil layer type, and in turn by its granulometry, texture, and alteration state. Our study of top and subsoils yields precious insights into surface expression variability, fluid–rock interaction processes, and sulphur deposition patterns within steam-heated zones. Processes at such a scale may strongly influence the migration of thermal manifestations, gas outputs, and ground subsidence within geothermal environments. From a broader perspective, our results will help assess the evolution of geothermal activity and related hazards in similar areas worldwide.

Water of Eastern Taiwan mud volcanoes: part II—trace element distribution of Lei-Gong-Huo mud volcano

Mud volcano (MV) is one of the most important channels for deep seated volatile materials to migrate to Earth’s surface in the sedimentary basins at subduction zones. It plays a meaningful role of elemental budget in hydrosphere. Waters of MV fluid emitted from 46 mud pools in MV Lei-Gong-Huo (LGH) in eastern Taiwan were sampled from October 2015 to July 2016 monthly. Previous research indicates that the chemical characteristic of fluid expelled by MV LGH is dominated by two-end-member mixing of water–rock interaction with sedimentary and igneous rocks (Chao et al., Front Earth Sci 9:750436, 2022). Trace elements of 165 mud pool samples, including Al, Co, Ni, Cu, Zn, As, Br, Rb, Mo, Sb, I, Cs, Pb and U, were measured. The results show that waters of MV LGH reveal similar chemical characteristics to low-temperature ridge-flank hydrothermal spring and marine pore water in anoxic conditions coupled with the addition of clay dehydration. Principle component analysis (PCA) with previous published variables (Chao et al., Front Earth Sci 9:750436, 2022) indicates the important factors are the source of water–rock interaction, the surface ion exchange, the redox condition of mud pool, and the evaporation. In summary, the concentration of trace elements in the waters expelled by MV LGH is in the range of nM to pM. Their behaviors are dominated by secondary factors during and after migration such as surface ion exchange in response to changes in pressure and temperature, redox state of the mud pool, and evaporation. Trace elements in MV water are not suitable for fluid source or provenance studies.

Comparison of preference of layers for laying eggs in Mud Pots Vs Nest Boxes

Comparison of preference of layers for laying eggs in Mud Pots Vs Nest Boxes

Influence of different containers and media on growth and flower yield of Dendrobium orchid cv. ‘Earsakul’

The present investigation entitled “Standardization of different containers and media on growth and flower yield of Dendrobium orchid cv. ‘Earsakul’ under shade net conditions in Floriculture Research Station, Thovalai, Tamil Nadu. The study results revealed that the highest vegetative and flower parameters was recorded in T8 - Perforated plastic pots with Coir compost + Brick pieces + Coconut husk + Charcoal+ Tiles pieces in equal parts viz., Plant height (9.26 cm) Leaf length (7.65 cm) No. of leaves per plant (8.74 cm) Leaf breadth (3.89 cm) Spike length (38.00 cm) Flowers Length (7.50 cm) Flowers Diameter (7.30 cm) No. of flowers per Plant (6.00) significant differences were observed among different containers and media on Dendrobium orchids cv. ‘Earsakul’. The lowest was recorded in the treatment T1 - Perforated mud pots with Coir compost Plant height (8.20 cm) Leaf length (7.17 cm) No. of leaves per plant (7.69 cm) Leaf breadth (3.48 cm) Spike length (27.00 cm) Flowers Length (6.80 cm) Flowers Diameter (6.00 cm) No. of flowers per Plant (3.00).

Investigasi Bawah Permukaan Pada Area Kawah Sikidang, Dieng, Jawa Tengah Menggunakan Metode Geolistrik

Sikidang crater geothermal manifestation area is located in Dieng geothermal field, Banjarnegara, Central Java Province, Indonesia. In 2019 more than 400,000 people visited Sikidang Crater tourism area. Some of the surface manifestation in this area include fumaroles, mud pools, steaming grounds, and altered ground. This research aim is to identify hydrothermal fluid below the surface and estimate the area of conductive zone using resistivity model from geoelectric data (dipole-dipole and Schlumberger configuration), surface temperature measurements, dan geological observation.Based on the results of 1D and 2D resistivity model, the low resistivity anomaly is thought to be a hydrothermal fluid that associated with surface geothermal manifestations appearence. The low resistivity anomaly also assumed to be associated with altered rocks in the study area, while the high resistivity anomaly is thought to be Pangonan andesitic lava with resistivity value above 1500 Ω.m. Several conductive zone dominantly identified in the Kawah Sikidang tourism area, however conductive zone also identified outside the tourism area.

:Etruscan Literacy in Its Social Context

:<i>Etruscan Literacy in Its Social Context</i>

Microbiological analysis, antimicrobial activity, heavy-metals content and physico-chemical properties of Fijian mud pool samples

The hot springs are home to a rich bacterial diversity which could be the source of enzymes, antibiotics and many other commercially important products. Most of the hot springs present in Fiji are unexplored and their analysis of microbial diversity could be of great interest in facilitating various industrial, agricultural and medicinal applications. This study is an attempt to evaluate the heavy metal concentration and to analyze the comprehensive bacterial diversity of two Fijian thermal mud pools, namely Sabeto and Tifajek. The two hot springs have a pH of 7.28 to 7.19 and a temperature of 32.2 to 38.8 °C, respectively. Mean metal concentrations of the studied mud samples ranged from 4.758 to 6.870 mg/kg and followed a decreasing sequence as Fe > Mn > Zn > Na > Ni > Cd > Ca > Cr > Cu. Levels of Fe, Na, Mn, Zn, Ni, Cd, Ca, Cr, Cu in the mud pool samples were within World Health Organisation (WHO) limits, while Cd was above regulatory limits. The heavy metals analysis results showed that both mud pools had high values for Cd, above the WHO limit of 3 mg/kg. In addition, 8 strains of actinomycetes were successfully identified for the first time in the Sabeto mud pool, where most of them showed antibacterial activity. The genetic identification of most isolates was determined in BLASTn analyses of their 16S rRNA sequences. Isolates were identified as that of Streptomyces, Nocardia and Rhodococcus genus. Further, AntiSMASH results of the closest relatives of cultured actinobacteria have shown to produce antibiotics, natural pesticides and other compounds of various usage. This study also found no fecal coliforms and supports existing knowledge and practice of using Fijian thermal mud pools for their therapeutic properties. Overall, the presented work indicated that the studied mud pools have therapeutic properties, harboring wealth of bacteria with antibiotic profiles and were risk free from health-related issues of heavy metals and disease-causing pathogens. It provides great insight into the studied mud pools which serves as a baseline from which further heavy metal monitoring or mitigation programs and microbial researches can be conducted.

Effect of ecological factors and breeding habitat types on Culicine larvae occurrence and abundance in residential areas Southern Thailand

Mosquitoes are a vector of human disease transmitting malaria, and many arboviruses such as dengue virus and Zika virus. This study determined mosquito larval occurrence and abundance in residential areas around Suratthani Rajabhat University as influenced by ecological factors and breeding container diversity. Mosquito larvae were collected using a standard dipping method from 95 locations during April through September 2019 and environmental factors such as physicochemical parameters of water in the breeding containers were measured. During the survey, a total of 194 houses were inspected, of which 58 were found to be infested with mosquito larvae, with a house index of 29.90, a container index of 25.55, and a Breteau index of 48.99. A total of 5,123 mosquito larvae were reported from seven breeding habitat types namely, plastics, cement, mud pots, glass, foam, discarded tires and natural materials. Among the collected larvae, Aedes albopictus (56.45%) was most prevalent, while Culex sp. (22.33%) and Aedes aegypti were less prevalent (21.21%). The most common mosquito larvae breeding habitats were plastics (44.22%) followed by discarded tires (18.14%). The spearman correlation analysis showed that the number of mosquito larvae were significantly positively correlated with the depths and width of containers (p<0.05). These findings are helpful in understanding the ecological factors and breeding habitat types that influence mosquito species and their abundance, and also in determining ways to control mosquito borne diseases.

Removal of algae from thermal mud pool: A case study in Koprukoy (Erzurum, Northeast (NE) Turkey) thermal spring area

ABSTRACT. Thermal spring areas, which are available globally, are used for recreational purposes or wellness applications because these areas have mineral-rich materials of thermal water and thermal muds. At the same time, thermal spring areas are one of the best habitats for algae among aquatic habitats. If algae formed on the surface of the thermal water in these areas, they create an ugly appearance and disrupt the aesthetics of the water because of their uncontrolled growth. The algae removal applications are the most effective methods for solution of these adversities in the thermal spring areas. In this work, experimental study was carried out to investigate the removal of algae from thermal water and thermal mud pools in the Delicermic-Koprukoy (Erzurum, NE Turkey) thermal spring area. For this purpose, some chemical materials were used for the removal of algae. The results of the experimental studies showed that the Al2SO3+CaO solution is a good material that provides 100% removal of algae from thermal water and thermal mud pools at pH 6.&#x0D; &#x0D; KEY WORDS: Algae, Algae removal, Thermal water, Thermal mud, Spring area &#x0D; &#x0D; Bull. Chem. Soc. Ethiop. 2022, 36(3), 545-553. &#x0D; DOI: https://dx.doi.org/10.4314/bcse.v36i3.5

Identifikasi Komposisi Mineral Batuan Teralterasi Menggunakan Spektroskopi SEM-EDX dan FTIR Pada Daerah Manifestasi Panas Bumi di Desa Mototompiaan Kecamatan Modayg Kabupaten Bolaang Mongondow Timur

Mototompiaan village is one part of the area that has geothermal potential, there are 2 types of manifestations that exist in the area that is in the form of hot springs and mud pool. The purpose of this study to determine mineral composition of rocks which is in the area around geothermal manifestation of hot springs by SEM-EDX and FTIR. Based on the result of identification using SEM-EDX in sample 1 shows that there are composition of Aluminium (Al) 6.11%, Fe 11,10% and Silica (Si) 82.79%, while sample 2 contains Aluminium (Al) 6.53%, Fe 9,16%, Co 2,85% and Silica (Si) 87.13%. The test result by FTIR spectroscopy can be known the types of minerals contained in rock samples are Hermatite, Arganite, Quartz, and Palygorskite.

Recognition of Geothermal Surface Manifestations: A Comparison of Machine Learning and Deep Learning

Geothermal surface manifestations (GSMs) are direct clues towards hydrothermal activities of a geothermal system in the subsurface and significant indications for geothermal resource exploration. It is essential to recognize various GSMs for potential geothermal energy exploration. However, there is a lack of work to fulfill this task using deep learning (DL), which has achieved unprecedented successes in computer vision and image interpretation. This study aims to explore the feasibility of using a DL model to fulfill the recognition of GSMs with photographs. A new image dataset was created for the GSM recognition by preprocessing and visual interpretation with expert knowledge and a high-quality check after downloading images from the Internet. The dataset consists of seven GSM types, i.e., warm spring, hot spring, geyser, fumarole, mud pot, hydrothermal alteration, crater lake, and one type of none GSM, including 500 images of different photographs for each type. The recognition results of the GoogLeNet model were compared with those of three machine learning (ML) algorithms, i.e., Support Vector Machine (SVM), Decision Tree (DT), and K-Nearest Neighbor (KNN), by using the assessment metrics of overall accuracy (OA), overall F1 score (OF), and computational time (CT) for training and testing the models via cross-validation. The results show that the retrained GoogLeNet model using transfer learning has significant advantages of accuracies and performances over the three ML classifiers, with the highest OA, the biggest OF, and the fastest CT for both the validation and test. Correspondingly, the three selected ML classifiers perform poorly for this task due to their low OA, small OF, and long CT. This suggests that transfer learning with a pretrained network be a feasible method to fulfill the recognition of the GSMs. Hopefully, this study provides a reference paradigm to help promote further research on the application of state-of-the-art DL in the geothermics domain.

Surface Thermal Manifestation Mapping in Kamojang Geothermal Field, West Java, Indonesia

Kamojang Geothermal Field is located in Bandung, West Java, Indonesia. Since 1978, this field has been producing electricity with total capacity about 235 MWe. Surface thermal manifestation monitoring is a powerful tool to monitor changes of reservoir condition. The investigation aimed at mapping new thermal manifestations and ground temperatures in Kamojang crater. The method employed is field mapping using drones and tracking. Ground temperatures were acquired directly in the field by measuring at 20 cm depth. Geologically, Kamojang Crater area is dominated by volcanic rocks such as andesite lava, pyroclastic breccia, tuff, and lapilli. It has undergone moderate to very strong alteration into clay, silica, iron oxide, and anhydrite minerals. The main geological structures that play a role in Kamojang area are Kendang, Patengteung, and Citeupeus Fault systems. Surface manifestations discharged in Kamojang area consist of mud pools/vents, hot springs/pools, steaming ground, and steam vents that are controlled by Citeupeus and Pateungteung Faults with a NE-SW orientation. The area was later referred to as Kamojang Crater, which consists of Manuk, Berecek, Sakarat, Kamojang, Kereta Api, Cikahuripan, Hujan, Loutak, Baru, Saar, and Inactive Craters. Several new hot spots have not been mapped in detail by previous research, including Timur Crater, Mud Pool Complex, and Tengah Crater. Meanwhile, an Inactive Crater to the north of study area indicates activity shown by boiling and bubbling hot pool. The thermal manifestation has a high temperature of 50.4 to 94.7°C. Manifestations in the form of liquids (mud and water) have an acidic fluid, with a pH ranging between 1.30 and 5.50. Ground temperatures in Kamojang Crater area range from 17 to 95°C. High temperature areas of 80 - 95oC are associated to thermal manifestations.

Reconstructing Hydrothermal Fluid Pathways and Storage at the Solfatara Crater (Campi Flegrei, Italy) Using Seismic Scattering and Absorption

Imaging of fluid pathways is crucial to characterize processes taking place in hydrothermal systems, a primary cause of volcanic unrest and associated hazards. The joint imaging of seismic absorption and scattering is an efficient instrument to map fluid flow at crustal scale, and specifically in volcanoes; however, this technique has so far been applied to image volcanoes and hydrothermal systems at the kilometre scale. Here, we use data from a meter-scale, active seismic survey inside the shallow structure of the Solfatara crater to obtain the first frequency-dependent near-surface scattering and absorption model of a hydrothermal system. The Solfatara crater is the place used to monitor historic unrest at Campi Flegrei caldera (Italy), a high-risk volcano under continuous surveillance due to its closeness to a densely populated area. Improving the imaging of the shallow part of this system is crucial to broaden the understanding of unrest processes that are progressively characterizing other portions of the eastern caldera. The scattering contrasts highlight the primary structural feature, a fault separating the hydrothermal plume from zones of CO2saturation nearing fumaroles. While high-absorption anomalies mark zones of high soil temperatures and CO2fluxes, low-absorption anomalies indicate zones of very shallow upflow and are caused by contrasts between liquid-rich and vapour-rich fluids coming from mud pools and fumaroles, respectively. All maps show a SW-NE trend in anomalies consistent with fluid-migration pathways towards the eastern fumaroles. The results provide structural constraints that clarify mechanisms of fluid migration inside the crater. The techniques offer complementary geophysical images to the interpretation of hydrothermal processes and prove that seismic attenuation measurements are suitable to map fluid pathways in heterogeneous media at a detailed scale.

Geothermal Surface Manifestation Identification Using Airborne Hyperspectral Imagery Case Study: Davis-Schrimpf Geothermal Field, Salton Sea, California

DOI:10.17014/ijog.9.1.119-130Research on surface geothermal evidence has been done extensively using remote sensing techniques. For detailed remote sensing exploration on geothermal areas, UAV and airborne based were preferred over the satellite-based sensor. In this research, anomalies in surface temperature, mineral occurrence, and ammonia emission were studied on a set of airborne hyperspectral imagery from NASA, the Hyperspectral Thermal Emission Spectrometer (HyTES). High-resolution surface temperature and mineral maps were able to identify and describe the mineralogy of the mud pots and gryphons at the Davis-Schrimpf Geothermal Field, Salton Sea, California. From the surface temperature map, the surface temperature of the geothermal features was measured at approximately 314°K (40oC) and higher. The purest pixels from MNF transformation of the first four cleanest bands of emissivity map produce endmembers that include the geothermal indicator minerals (barite, anhydrite, quartz, gypsum). Based on the mineralogy deposits, these manifestations are classified as potassic alteration types from a porphyry system that could be an indication of an active geothermal system. This also explains that the surface features are part of the upper reservoir of the Salton Sea Geothermal Field. On the other hand, ammonia detection that was performed in this research failed to get any clear recognition from the simple image processing. It is concluded that the airborne hyperspectral imagery could be a reliable option for remote sensing geothermal exploration, as it was able to characterize the surface geothermal manifestation with quite good detail using this imagery from a wide area of survey.

Geochemistry of trace metals and Rare Earth Elements in shallow marine water affected by hydrothermal fluids at Vulcano (Aeolian Islands, Italy)

Trace metals and Rare Earth Element (REE) are amply discharged by submarine hydrothermal vents, sometimes leading to the formation of ore deposits of economic interest. We report on first data on the geochemical processes involving REE and trace metals, at the solid-liquid interface, in the hydrothermal area of Levante Bay at Vulcano Island (Aeolian Archipelago, Italy). Samples were collected from several submarine springs and seeps, a mud pool and one thermal well, and analyzed for Al, Si, Ti, V, Cr, Mn, Fe, Co, As, Rb, Sr, Cs, Ba, U and REE, besides major ions.Within the bay, hydrothermal fluids contaminate seawater and promote the leaching of metals from sediments through the dissolution of CO2 and H2S, while the particulate matter removes several elements from the water. The leaching of the bottom sediments and the contribution of steam-heated water produce an enrichment of some metals and REE in the Levante Bay with respect to the concentrations expected in the ambient seawater. An enrichment up to one order of magnitude is measured for Fe, Al, Ba, Cs and Rb, and up to two orders of magnitude for Mn in the submarine samples. Other transition metals (Ti, V, Co, Cr), U, As and Sr have concentrations similar or slightly lower than the ambient seawater. REE are in concentrations higher than in ambient seawater up to two orders of magnitude. Despite being significantly higher than uncontaminated seawater, the concentrations of some metals (namely Fe, Al, Ti, Cr, V, Co, U) and REE in most samples are lower than expected by the mixing between seawater and the steam-heated water, discharging from submarine springs. Indeed, equilibrium and reaction path modeling indicate the likely precipitation of Fe-oxyhydroxides, able to remove minor elements, such as Ti, Cr, Co, V and As, and REE. The last ones are significantly removed by newly-forming solid phases, due to the presence of a large amount of Fe released by the acidic fluids through the leaching of sediments. The low pH limits the formation of solution complexes of REE with carbonate ions (the main complexing agent for REE in seawater), whereas the sorption onto particles is still effective, even at close distance from the submarine springs and seeps.This study brings new insights on the geochemical processes occurring in submarine hydrothermal systems, in particular, those in subduction-related context.

Two-End-Member Mixing in the Fluids Emitted From Mud Volcano Lei-Gong-Huo, Eastern Taiwan: Evidence From Sr Isotopes

Mud volcano is one of the most important conduits for deep seated materials to migrate upward in sedimentary basins, convergent margins, and subduction zones. Understanding their temporal and spatial characteristics and variations provides us the important information on fluid sources and chemical compositions at depth. Mud volcano Lei-Gong-Huo (MV LGH) is a unique mud volcano, which is located on the mélange formation lying on the andesitic volcanic arc. Fluids emitted from 46 mud pools in MV LGH in eastern Taiwan were sampled and their major trace constitutes as well as H, O, and Sr isotopes (87Sr/86Sr and δ88Sr) were measured. Major constitutes of the fluids are Cl−, Na, and Ca. Compared with seawater, LGH fluids have lower Cl−, δD, δ18O, Na/Cl, K/Cl, and Mg/Cl but higher Ca/Cl ratios, indicating water–rock interaction of igneous rock and the ancient seawater at the source region. This interpretation is further supported by Sr isotopes, which show low value of 87Sr/86Sr ratio down to 0.70708. The result of spatial distribution showing strong negative correlation between Na and Ca concentration as well as Ca and 87Sr/86Sr ratios indicates that two end-member mixing is the major chemical characteristic. The fluids interacting with igneous rock carry high Ca, high δ88Sr, low Na, and low 87Sr/86Sr ratio, while those interacting with sedimentary rock carry low Ca, low δ88Sr, high Na, and high 87Sr/86Sr ratio. The source from the igneous region dominates the eastern and southeastern parts of the mud pools while sedimentary source dominates the western and northwestern parts. Most mud pools show mixing behavior between the two sources. Some of the sedimentary-dominated mud pools reveal existence of residual ancient water as indicated by 87Sr/86Sr. The major factor to fractionate the stable Sr isotopes in LGH waters is the source lithology. In summary, fluids emitted by mud pools in LGH originate from two sources, which are water–rock interactions of igneous rock with the ancient seawater from the east and sedimentary rock from the west at depth, resulting from the complex geologic background of mélange formation.

Controls on S mineral formation and preservation in hydrothermal sediments: Implications for the volcanic, aqueous, and climatic history of Gusev crater, Mars

Acidic hydrothermal and fumarolic surface deposits within the Columbia Hills in Gusev crater on Mars were found to have elevated concentrations of Fe-Mg-Ca-sulfate minerals. However, this is inconsistent with analogous terrestrial hydrothermal settings that are usually enriched in elemental sulfur (S). Consequently, this raises questions about the origin and hydrothermal history of the Gusev sediments. To address this discrepancy, we analyzed quantities and S isotope compositions of S-bearing minerals in hydrothermal sediment samples from acidic hot springs, mud pots, and fumaroles with elevated H2S emissions in Iceland and the United States (e.g., Valles Caldera, Lassen, and Yellowstone). Our results indicate that the typical concentrations (e.g., inter-quartile range) of elemental S and sulfide minerals (0.3 to 10.5 wt% S, but as high as ~75 wt% S; and 0.1 to 1.7 wt% S, but as high as ~10 wt% S) are significantly higher compared to sulfate (0.1 to 1.1 wt% S, but as high as ~4.5 wt% S) in the surface hydrothermal deposits. In most cases, the concentrations of elemental S, sulfides, and sulfates in the sediments decreased with increasing hydrological connectivity and in wetter climates. Similar δ34S values between sulfate (−0.1 to +1.4‰) and elemental S (−0.4 to +1.6‰) compared to lower δ34S of sulfide (−2.4 to +0.4‰) suggest that more sulfate is likely derived from the subsequent oxidation of elemental S than sulfide. Conversely, minor amounts of sulfate are formed via direct oxidation of H2S which had higher δ34S values (+1.1 to +5.9‰). Our laboratory experiments carried over a wide range of temperatures (25, 65, and 85 °C) and low pH (~2) indicate that elemental S and pyrite undergo subsequent oxidation to sulfate via both ferric iron (Fe3+) and O2. While the amount of sulfate increased with increasing temperature in the presence of both Fe3+ and O2, Fe3+ appears to be a more efficient oxidizer than O2. For example, pyrite oxidation by only Fe3+ resulted in ~1.5× more sulfate (~80 to 180 mg/L SO42−) than by only O2 (~40 to 140 mg/L SO42−). In contrast, considerably less sulfate was formed during the oxidation of elemental S, although in the presence of O2 ~10× more sulfate (~0.1 to 45 mg/L SO42−) was formed than when Fe3+ was present (~0.3 to 7.5 mg/L SO42−).Despite the prevalence of sulfate minerals rather than elemental S and sulfides in the hydrothermal Gusev deposits on Mars, the total S concentrations measured by the Spirit rover (2.9 to 9.3 wt% S) are highly comparable to the total S in hydrothermal sediments formed in colder and moderately wet climates such as coastal Iceland (1.8 to 10.7 wt% S). This contrasts with sediments formed in the high-altitude and drier climate of Valles Caldera (9.9 to 37.6 wt% S), or the wetter climates of Yellowstone (4.1 to 17.3 wt% S) and Lassen (0.5 to 3.5 wt% S). Because water is needed to further oxidize the hydrothermal elemental S and sulfide to sulfate, we infer that the aqueous conditions must have persisted in Gusev crater for a period of time after the main hydrothermal activity ceased. Later, under low water-to-rock conditions with little (or no) H2S emission, complete oxidation of the Gusev hydrothermal deposits likely took place and led to the formation of the sulfate minerals that were identified by the Spirit rover.

Design and development of all wheel drive transmission system for an all-terrain vehicle

An All-Wheel Drive Transmission system powered by a 10 HP Briggs & Stratton engine is designed for a single-seater all-terrain vehicle. Because of the engine power limitation, it's important to reduce the vehicle's weight and improve its performance. The aim is to increase the traction of the vehicle and it must be able to climb high grades, cross slippery mud pools, and snow tracks with minimum drive slip. While performing, the system must be reliable and not fail under any circumstances. The study focuses on the optimized calculation of engine performance, vehicle mass, air drag, rolling resistance, continuously variable transmission (CVT) shifting, gearbox reduction ratio, gear selection, shaft, and casing. The design and analysis process includes the development of a compound gear train with gears having a minimum diameter and face width, to lower the rotational inertia of the system and included the calculation of static failure from contact and bending stresses, gearbox housing, shafts, and bearings. All components are designed in Solidworks 2016 and analyzed in Ansys Workbench 19.2.

APPLICATION OF UPWARD CONTINUATION FILTER FOR GEOMAGNETIC DATA INTERPRETATION IN GONDANG, BOJONEGORO AREA

There are several manifestations of hot springs and mud pools in Gondang area, Bojonegoro, East Java, there were. This can be an indication of certain geological conditions. The description of these conditions can be done by measuring the geomagnetic method. A total geomagnetic anomaly has been generated through some geomagnetic values recorded in the region, which has been corrected using IGRF correction and diurnal correction. These steps were done to reduce external influences on the real value of the data. This research will use several variations of values in the Upward Continuation filter and one of them will be chosen to proceed as a model. Upward Continuation Filter is a process of transforming potential field data from a flat plane towards the higher plane. The purpose of this study is to compare the results of contour maps on several variations of the Upward Continuation value, to obtain the results of the separation of residual and regional anomalies using the Upward Continuation method, and to determine the value of the susceptibility distribution of inversion modeling in the Gondang region, Bojonegoro. Based on the results of data processing, it is known that the upward continuation value used is 100mdatum with a magnetic intensity value in the regional anomaly of 106.5 nT to 509.0. While the value of the residual anomaly is -232.1 nT to 159.4 nT. The 3D model was made using this residual anomaly which shows the low susceptibility distribution value in the range of -0.0298 to -0.0135 SI around the manifestation area, whereas the high susceptibility value has a value range of 0.0114 to 0.0466 SI interpreted as rock intrusion. Rock intrusion occurs within the area around the manifestation of mud pools.

Silica Sinter and the Evolution of Hot Springs in the Alvord/Pueblo Valleys, Southeast Oregon, USA

Hot springs in the Alvord/Pueblo valleys in southeastern Oregon are analogous to Basin-and-Range hydrothermal systems where heat source and permeable pathways are met through crustal thinning. Silica sinter deposition at Mickey Springs, Alvord Valley, predates the late Pleistocene high stand of pluvial Lake Alvord. At Borax Lake, Pueblo Valley, sinter deposition occurred during the Holocene. This study examines the evolution of springs at Mickey Springs, where three morphologies of sinter are present: (1) basalt clasts surrounded by sinter in interbedded conglomerate and sandstone, (2) pool-edge and aprons of sinter surrounding depressions (12–32 m diameter), and (3) quaquaversal sinter mounds with pool-edge sinter. The oldest sinter occurs in silica-cemented conglomerate and sandstone, where deposition occurred prior to 30 kya. Deposition around broad depressions and mounds occurred after 30 kya but before water levels began to rise in pluvial Lake Alvord. Thermoluminescence dates suggest sinter deposition ceased before 18 kya when silt and clay filled inactive vents and buried aprons. A few mounds hosted active springs after sinter deposition ceased but while submerged in pluvial Lake Alvord. Now, high-temperature springs, steam vents, and mud pots are concentrated in a 50 × 50 m area near the southern edge of the spring area.