The alteration of effusive rocks due to acidic leaching by shallow thermal waters: The Baranskii geothermal system, Iturup Island

The Mud Volcano area in Yellowstone National Park provides an example of a vapor‐dominated geothermal system. A test well drilled to a depth of about 347 ft penetrated the vapor‐dominated reservoir at a depth of less than 300 ft. Subsequently, 16 vertical electrical soundings (VES) of the Schlumberger type were made along a 3.7‐mile traverse to evaluate the electrical resistivity distribution within this geothermal field. Interpretation of the VES curves by computer modeling indicates that the vapor‐dominated layer has a resistivity of about 75–130 ohm‐m and that its lateral extent is about 1 mile. It is characteristically overlain by a low‐resistivity layer of about 2–6.5 ohm‐m, and it is laterally confined by a layer of about 30 ohm‐m. This 30‐ohm‐m layer, which probably represents hot water circulating in low‐porosity rocks, also underlies most of the survey at an average depth of about 1000 ft. Horizontal resistivity profiles, measured with two electrode spacings of an AMN array, qualitatively corroborate the sounding interpretation. The profiling data delineate the southeast boundary of the geothermal field as a distinct transition from low to high apparent resistivities. The northwest boundary is less distinctly defined because of the presence of thick lake deposits of low resistivities. A broad positive self‐potential anomaly is observed over the geothermal field, and it is interpretable in terms of the circulation of the thermal waters. Induced‐polarization anomalies were obtained at the northwest boundary and near the southeast boundary of the vapor‐dominated field. These anomalies probably are caused by relatively high concentrations of pyrite.

Download Full-text

A seismic and gravity study of the McGregor geothermal system, southern New Mexico

Geophysics ◽

10.1190/1.1487048 ◽

2001 ◽

Vol 66 (4) ◽

pp. 1002-1014 ◽

Cited By ~ 2

Author(s):

T. M. O’Donnell ◽

K. C. Miller ◽

J. C. Witcher

Keyword(s):

New Mexico ◽

Heat Flow ◽

Water Table ◽

Alluvial Fan ◽

Hot Water ◽

Thermal Waters ◽

Small Scale ◽

Geothermal System ◽

Velocity Models ◽

Basin Fill

Seismic and gravity studies have proven to be valuable tools in evaluating the geologic setting and economic potential of the McGregor geothermal system of southern New Mexico. An initial gravity study of the system demonstrated that a gravity high coincides with the heat‐flow high. A subsequent seismic reflection survey images a strong reflector, interpreted to be associated with a bedrock high that underlies the gravity and heat‐flow highs. A single reflection, which coincides with the water table, occurs within the Tertiary basin fill above bedrock. This reflector is subhorizontal except above structurally high bedrock, where it dips downward. This observation is consistent with well data that indicate a bedrock water table 30 m lower than water in the basin‐fill aquifer. Velocity models derived from seismic tomography show that the basin fill has velocities in the range of 800 to 4000 m/s and that the bedrock reflector coincides with high velocities of 5000 to 6000 m/s. Low‐velocity zones within the bedrock high are interpreted as karsted bedrock with solution‐collapse breccias and cavities filled with hot water. Higher velocity material that flanks the bedrock high may represent an earlier stage of basin fill or older alluvial‐fan deposits. The heat‐flow anomaly appears to be constrained to the region of shallowest bedrock that lacks these deposits, suggesting that they may act as an aquitard to cap underlying bedrock aquifers or geothermal reservoirs. Taken together, these observations suggest that the geothermal system is associated with karsted and fractured structurally high bedrock that serves as a window for upwelling and outflow of thermal waters. Thermal waters with a temperature as high as 89°C have the potential for space heating, geothermal desalinization, and small‐scale electrical production at McGregor Range.

Download Full-text

Hydrogeochemical Characterization of GeothermalWater in Arjuno-Welirang, East Java, Indonesia

Journal of Applied Geology ◽

10.22146/jag.39979 ◽

2018 ◽

Vol 2 (2) ◽

pp. 48

Author(s):

Vanadia Martadiastuti ◽

Agung Harijoko ◽

I Wayan Warmada ◽

Kotaro Yonezu

Keyword(s):

Water Samples ◽

Hot Springs ◽

Shallow Groundwater ◽

Thermal Waters ◽

Geothermal System ◽

Volcanic Complex ◽

Geothermal Fluids ◽

Geothermal Fields ◽

System Data ◽

Hydrogeochemical Characterization

Arjuno-Welirang Volcanic Complex (AWVC) is one of geothermal fields whichlocated in East Java province, Indonesia. It belongs to a Quarternary volcanic arc and has potential for development of electricity. The field is situated in a steep volcanic terrain and there are only few geothermal manifestations, i.e., hot springs, fumaroles, solfataras, steaming ground and hydrothermal alteration. This study aims to classify the type and source of geothermal fluid and to estimate the reservoir condition of Arjuno- Welirang geothermal system. Data are obtained from collecting water samples including hot springs, cold springs, river waters and rain water, then they are analyzed using ICP-AES, titration and ion chromatography.All thermal waters have temperatures from 39.5–53°C and weakly acidic pH (5.2–6.5). Cangar and Padusanhot springs show bicarbonate water, formed by steam condensing or groundwater mixing. On the other hand, Songgoriti shows Cl-HCO3 type, formed by dilution of chloride fluid by either groundwater or bicarbonate water during lateral flow. All of the waters represent immature waters, indicating no strong outflow of neutral Cl-rich deep waters in AWVC. Cl/B ratios show that all water samples have a similar mixing ratio, showing they are from common fluid sources. However, Padusan and Songgoriti have higher Cl/B ratios than Cangar, suggesting that geothermal fluids possibly have reacted with sedimentary rocks before ascending to the surface. All waters were possibly mixed with shallow groundwater and they underwent rock-water reactions at depth before ascending to the surface. An estimated temperatures reservoir calculated using CO2 geothermometer yielded temperatures of 262–263 °C based on collecting of fumarole gas at Mt. Welirang crater. According to their characteristics, Cangar and Padusan are associated with AWVC, while Songgoriti is associated with Mt. Kawi.

Download Full-text

Behavior of Nuclear Waste Elements During Hydrothermal Alteration of Glassy Rhyolite in an Active Geothermal System: Yellowstone National Park, Wyoming

MRS Proceedings ◽

10.1557/proc-44-557 ◽

1984 ◽

Vol 44 ◽

Author(s):

Neil C. Sturchio ◽

Martin G. Seitz

Keyword(s):

Hydrothermal Alteration ◽

Nuclear Waste ◽

Yellowstone National Park ◽

National Park ◽

Thermal Waters ◽

Geothermal System ◽

Altered Rock ◽

Active Geothermal System

AbstractThe behavior of a group of nuclear waste elements (U, Th, Sr, Zr, Sb, Cs, Ba, and Sm.d)u ring hydrothermal alteration of glassy rhyolite is investigated through geochemaical analyses of whole rocks, glass and mineral separates, and thermal waters. Significant enrichments of U, Sr, Sb, Cs, and Ba are found in altered rock relative to unaltered rock. Excess Sr, Cs, and Ba are concentrated in zeolites in altered rock. Excess U is associated with titanomagnetite surfaces. Th, Zr, and Sm are relatively immobile during alteration, and are strongly concentrated in celadonite.

Download Full-text

Origin of thermal waters from the Hakone geothermal system, Japan.

GEOCHEMICAL JOURNAL ◽

10.2343/geochemj.19.27 ◽

1985 ◽

Vol 19 (1) ◽

pp. 27-44 ◽

Cited By ~ 15

Author(s):

Sadao Matsuo ◽

Minoru Kusakabe ◽

Mariko Niwano ◽

Tomio Hirano ◽

Yasue Oki

Keyword(s):

Thermal Waters ◽

Geothermal System

Download Full-text

Isotope hydrogeology and geothermometry of the Mount Meager geothermal area

Canadian Journal of Earth Sciences ◽

10.1139/e82-126 ◽

1982 ◽

Vol 19 (7) ◽

pp. 1454-1473 ◽

Cited By ~ 21

Author(s):

I. D. Clark ◽

P. Fritz ◽

F. A. Michel ◽

J. G. Souther

Keyword(s):

Inorganic Carbon ◽

Dissolved Inorganic Carbon ◽

Environmental Isotopes ◽

Thermal Waters ◽

Geothermal System ◽

Altitude Effect ◽

Geothermal Resources ◽

Geothermal Waters ◽

Maximum Temperatures ◽

Cold Groundwaters

A survey of stable and radioactive environmental isotopes has been carried out in order to investigate the recharge, thermal history, age, and geothermometry of the thermal waters at Mount Meager, British Columbia, a Quaternary volcano that is currently the site of active exploration for geothermal resources. Isotope determinations include 18O, 2H, and 3H in precipitation, thermal and cold groundwaters, and glacier ice; 13C and 14C in dissolved inorganic carbon; 18O and 34S in dissolved sulphate from thermal and cold groundwaters; and 13C and 18O in hydrothermal calcite crystals. Major ion analyses were performed on thermal and cold spring waters.Precipitation data are used to define the local meteoric water line and to document the altitude effect on waters recharging the geothermal system, demonstrating that there are two hydrogeologically separate reservoirs recharged at different altitudes. Both pools of geothermal waters have experienced shifts of between +0.5 and +2.5‰ in δ18O values, indicating a limited degree of 18O exchange with hot silicate minerals.Tritium contents indicate that these waters recharged prior to 1955. 13C contents of dissolved inorganic carbon and hydrothermal calcites from drill core document contamination of the thermal waters with "dead" volcanogenic CO2 plus carbon exchange with fracture calcite, which precludes the possibility of "dating" the thermal waters using 14C.Several chemical and isotopic geothermometers are used to estimate the maximum temperatures experienced by the thermal waters. The fractionation of 18O between SO42− and H2O in these waters gives calculated maximum temperatures of less than 140 °C. The Mg-corrected Na–K–Ca geothermometer shows excellent correlation with the SO4–H2O estimates with maximum temperatures of less than 140 °C. Fractionation of 13C and 18O in the systems CaCO3–CO2 and CaCO3–H2O using hydrothermal calcites and borehole fluids also offers no indications of subsurface temperatures in excess of 140 °C. Silica geothermometer results are not reliable because of equlibrium with amorphous silica phases in the subsurface.It is concluded that these thermal waters are not deeply circulating and have not experienced temperatures in excess of 140 °C.

Download Full-text

The recharge area for the Coso, California, geothermal system deduced from [delta]D and [delta]180 in thermal and non-thermal waters in the region

Open-File Report ◽

10.3133/ofr80454 ◽

1980 ◽

Cited By ~ 1

Author(s):

Robert O. Fournier ◽

J.M. Thompson

Keyword(s):

Thermal Waters ◽

Geothermal System ◽

Recharge Area

Download Full-text

The main geothermal reservoirs in the south Algeria and their interest for local economic development

E3S Web of Conferences ◽

10.1051/e3sconf/20198001006 ◽

2019 ◽

Vol 80 ◽

pp. 01006

Author(s):

Abdelkader Ait-Ouali ◽

Salima Ouali ◽

MM Hadjiat ◽

Khaled Imessad

Keyword(s):

Multidisciplinary Approach ◽

Local Economic Development ◽

Geothermal Reservoir ◽

Thermal Waters ◽

Geothermal System ◽

Chemical Characteristics ◽

Geochemical Analysis ◽

Reservoir Temperature ◽

Hot Arid Climate ◽

Very High

The study area is one of the important geothermal provinces in south Algeria. It is characterized by a hot arid climate with intense dryness and very high evaporation rates. The Albian geothermal system is exploited by the wells mainly for domestic and agricultural purposes. The sandstone Continental Intercalary (CI) formation constitutes the reservoir for the Albian aquifer, covering an area of 600,000 km2. This reservoir is covered by calcareous formations which yield the chemical characteristics of highly mineralized Na-Cl type representing the deep thermal waters and Ca-SO4 type determined the presence of evaporate lithology . For a better understanding of geothermal reservoir characteristic, a multidisciplinary approach was adopted, including hydrogeochemistry and geothermometry. More than fifty samples collected from wells recently in 2017 with a temperature average between 38 and 60° C and conductivities range from 2010 to 3460 μS/cm. Geochemical analysis of those thermal waters exhibits a certain degree of salinity with sodium-chloride type waters domination. The maximal geothermal reservoir temperature estimated using geothermometry is about 120°C.

Download Full-text

Numerical modeling as a tool for evaluating the renewability of geothermal resources: the case study of the Euganean Geothermal System (NE Italy)

Environmental Geochemistry and Health ◽

10.1007/s10653-021-01028-4 ◽

2021 ◽

Author(s):

Filippo Torresan ◽

Leonardo Piccinini ◽

Mauro Cacace ◽

Marco Pola ◽

Dario Zampieri ◽

...

Keyword(s):

System Development ◽

Sharp Decrease ◽

Scenario Planning ◽

Thermal Waters ◽

Geothermal System ◽

Veneto Region ◽

Geothermal Resources ◽

Ne Italy ◽

Human Footprint ◽

Geological Processes

AbstractRenewable natural resources are strategic for reducing greenhouse gas emissions and the human footprint. The renewability of these resources is a crucial aspect that should be evaluated in utilization of scenario planning. The renewability of geothermal resources is strictly related to the physical and geological processes that favor water circulation and heating. In the Veneto region (NE Italy), thermal waters of the Euganean Geothermal System are the most profitable regional geothermal resource, and its renewability assessment entails the evaluation of fluid and heat recharge, regional and local geological settings, and physical processes controlling system development. This renewability assessment is aimed at defining both the importance of such components and the resource amount that can be exploited without compromising its future preservation. In the second part of the twentieth century, the Euganean thermal resource was threatened by severe overexploitation that caused a sharp decrease in the potentiometric level of the thermal aquifers. Consequently, regulation for their exploitation is required. In this work, the renewability of the Euganean Geothermal System was assessed using the results from numerical simulations of fluid flow and heat transport. The simulations were based on a detailed hydrogeological reconstruction that reproduced major regional geological heterogeneities through a 3D unstructured mesh, while a heterogeneous permeability field was used to reproduce the local fracturing of the thermal aquifers. The model results highlight the role played by the resolved structural elements, in particular the subsurface high-angle faults of the exploitation field, and by the anomalous regional crustal heat flow affecting the central Veneto region.

Download Full-text

Isotopic Investigation of the Surdulica Geothermal System

Radiocarbon ◽

10.1017/s0033822200012510 ◽

1989 ◽

Vol 31 (03) ◽

pp. 893-901 ◽

Cited By ~ 3

Author(s):

Branislav Milovanović ◽

Svetislav Stanković ◽

Miomir Komatina ◽

Munevera Hadžišehović ◽

Mladen Župančić ◽

...

Keyword(s):

Stable Isotope ◽

Meteoric Water ◽

Thermal Waters ◽

Geothermal System ◽

Independent Data ◽

Recharge Area ◽

Tritium Content ◽

Geothermal Waters ◽

Water Formation ◽

Natural Springs

The object of our investigation was to study a mechanism of water formation in the Surdulica geothermal system (recharge area, age and homogeneity of the waters). We collected 56 samples to determine the chemical, stable isotope, 14C and tritium content of the waters. We found large stable isotope variations in precipitation collected at different altitudes, whereas the geothermal waters are largely homogeneous and seasonally independent. Data on springs and rivers, the local meteoric water line and recharge area were obtained. Three groups of groundwater were identified by age – modern from natural springs, old from mines and very old from the Vranjska Banja. Because the initial 14C activity of infiltrated waters from the recharge area is unknown, the age of thermal waters can only be inferred, from HCO3 −, 14C and 3H content, to be 10,000 to 28,000 years old.

Download Full-text