Upper Jurassic travertine at El Macanudo, Argentine Patagonia: a fossil geothermal field modified by hydrothermal silicification and acid overprinting

2017 ◽  
Vol 155 (6) ◽  
pp. 1394-1412 ◽  
Author(s):  
DIEGO M. GUIDO ◽  
KATHLEEN A. CAMPBELL
Keyword(s):  
Hot Spring ◽  
Sedimentary Facies ◽  
Upper Jurassic ◽  
Geothermal Field ◽  
Hydrothermal Systems ◽  
Geothermal Systems ◽  
Volcanic Event ◽  
Exceptional Preservation ◽  
Argentine Patagonia ◽  
Clay Formation

AbstractThe Deseado Massif hosts numerous Late Jurassic (150 Ma) fossil geothermal systems related to an extensive volcanic event developed in a diffuse extensional back-arc setting. Detailed mapping, petrography and mineralogical observations of El Macanudo outcrops verify that it represents a hot-spring-related travertine partially replaced by silica and delineated by six sedimentary facies. These are large concentric cones (F1), laminated vertical columnar structures (F2), porous layers (F3), shrubby and irregular lamination (F4), low-amplitude wavy bedding (F5) and mounds and breccias (F6). The Macanudo Norte Outcrop rocks constitute a silica-replaced travertine sequence, with development of large conical stromatolites in a deep pool or geothermally influenced shallow lacustrine environment, surrounded by a subaerial travertine apron terrace; whereas, the Macanudo Sur Outcrop is a subaerial travertine mound sequence. Structurally controlled vent areas occur in both northern (F1) and southern (F6) outcrops, mainly located along regional NNE- and ENE-trending faults. The other sedimentary units display a concentric distribution of travertine facies with respect to the interpreted vent areas. The El Macanudo palaeo-hot spring deposit is situated in an eroded Jurassic volcanic centre, and records a complex evolutionary-fluid history. The sediments archived three different Jurassic events, when large and long-lasting hydrothermal systems were active across the region. This relative temporal sequence was formed by: (1) travertine precipitation; (2) development of a silica cap, where early silicification was responsible for exceptional preservation of some stromatolitic fabrics; and (3) acid alteration, recorded by dissolution textures and clay formation, and caused by a palaeo-phreatic water-level drop.

Expanding a Geothermal Field Downwards. The Challenge of Drilling a Deep Well in the Hengill Area, SW Iceland.

2020 ◽  
Author(s):  
Gunnar Gunnarsson ◽  
Vignir Demusson ◽  
Ingvi Gunnarsson ◽  
Bjarni Reyr Kristjánsson ◽  
Sigrún Tómasdóttir ◽  
...  
Keyword(s):  
Geothermal Field ◽  
Hydrothermal Systems ◽  
Measured Temperature ◽  
Geothermal Systems ◽  
Magma Body ◽  
Deep Well ◽  
Well Design ◽  
Geothermal Fields ◽  
Original Plan ◽  
Promising Target

<p><span>In 1986 a well, which was planned as a convetional production well in the Nesjavellir Field in the Hengill Area, SW Iceland, was unexpectedly drilled into a very hot formation at the depth of 2.1 km. The measured temperature in the lowest part of the well was 380°C, which was the upper range of the measuring tool used. Thus, the bottom-hole temperature was most probably higher. No one expected to hit such a hot body in this place and the well design was not appropriate to handle such high temperatures and resulting pressures. Thus, the lower parts of that well were closed off and it has since then been operated as a conventional geothermal well.</span></p><p><span>This incidence sparked the idea of drilling deeper into volcanic hydrothermal systems in Iceland in order to gain a better understanding of the roots of the geothermal systems and to be able to produce fluids with higher enthalpy. The Iceland Deep Drilling Project (IDDP) is supposed to realize that idea. The IDDP project is a consortium of domestic and international partners, both from industry and academia. The three power companies in Iceland, which operate power-production in volcanic geothermal fields (Landsvirkjun, HS-Orka, OR), committed themselves to drill one deep well each in a field of theirs. </span></p><p><span>To date two wells have been drilled in the IDDP project. The first one, IDDP-1, was drilled in the Krafla Field, N Iceland, which is operated by Landsvirkjun, and the second well, IDDP-2, was drilled in the Reykjanes Field, which is operated by HS-Orka. The original plan was to drill down to 4-5 km. However, the IDDP-1 in Krafla was drilled into magma of rhyolite composition at the depth of 2.1 km and could therefore not be drilled further. During flow tests, it was flowing superheated steam at high pressure at well head temperature of 450°C. The power capacity was estimated to be 36 MW<sub>e</sub>. However, due to hostile chemistry of the fluid and damaged casing, the well had to be abandoned and closed after the well tests. IDDP-2 was drilled down to 4,659 m. The highest temperature measured in the bottom of the well was 426°C at a pressure of 340 bar. It was also possible to obtain core samples from the bottom of the well. However, due to damaged casing it hasn't been possible to do further temperature and pressure measurements in the lower parts of IDDP-2. To date flow tests in IDDP-2 have not started.</span></p><p><span>The next well in the IDDP project is planned in the Hengill Area. The most promising target is the hot body that started it all in the Nesjavellir Field. According to experience from IDDP-1 and IDDP-2 the main techincal obstacle is the casing. Both wells have serious casing problems. The magma body unexpectedly hit by IDDP-1 illustrated that careful interdisciplinary preperations are needed when drilling into the unknown. Currently, few projects are ongoing to fill the knowledge gaps in order to minimize risk and maximize the probability of successful drilling. </span></p>

Life is everywhere in sinters: examples from Jurassic hot-spring environments of Argentine Patagonia

2019 ◽  
Vol 156 (9) ◽  
pp. 1631-1638 ◽  
Author(s):  
Diego M Guido ◽  
Kathleen A Campbell ◽  
Frédéric Foucher ◽  
Frances Westall
Keyword(s):  
Early Life ◽  
Hot Spring ◽  
Biotic Interactions ◽  
Carbonaceous Material ◽  
Geothermal Field ◽  
Argentine Patagonia ◽  
Life On Earth ◽  
Ubiquitous Presence ◽  
Deseado Massif

AbstractJurassic siliceous hot-spring (sinter) deposits from Argentine Patagonia were evaluated to determine the distribution and preservation quality of their entombed microbial fabrics. Detailed study showed that the Claudia palaeo-geothermal field hosts the best-preserved sinter apron in the Deseado Massif geological province, where we also found hot-spring silica–biotic interactions extending into hydrothermally influenced fluvial and lacustrine settings. Carbonaceous material was identified by petrography and Raman spectroscopy mapping; it is inter-laminated with silica across proximal vent to distal marsh facies. The ubiquitous presence of microbial biosignatures has application to studies of hydrothermal settings of early life on Earth and potentially Mars.

scholarly journals Multiscale Microbial Preservation and Biogeochemical Signals in a Modern Hot-Spring Siliceous Sinter Rich in CO2 Emissions, Krýsuvík Geothermal Field, Iceland

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 263
Author(s):  
Jose Javier Álvaro ◽  
Mónica Sánchez-Román ◽  
Klaas G.J. Nierop ◽  
Francien Peterse
Keyword(s):  
Fatty Acids ◽  
Dissolved Inorganic Carbon ◽  
Hot Spring ◽  
Carbon Isotopic Composition ◽  
Methanogenic Archaea ◽  
Geothermal Field ◽  
Carbon Isotopic ◽  
Siliceous Sinter ◽  
Episodic Fluctuations ◽  
Abandoned Meanders

The microbial communities inferred in silica sinter rocks, based on multiscale morphological features (fabrics and textures) and the presence of lipid biomarkers and their carbon isotopic composition, are evaluated in the Krýsuvík geothermal area of Iceland. Close to vent environments (T > 75 °C and pH 1.7‒3), stream floors are capped with homogeneous vitreous crusts and breccia levels, with no distinct recognizable silicified microbes. About 4 m far from the vents (T 75‒60 °C and pH 3‒6) and beyond (T < 60 °C and pH 6‒7.6), microbial sinters, including wavy and palisade laminated and bubble fabrics, differ between abandoned meanders and desiccated ponds. Fabric and texture variances are related to changes in the ratio of filament/coccoid silicified microbes and associated porosity. Coatings of epicellular silica, less than 2 µm thick, favor identification of individual microbial filaments, whereas coalescence of opal spheres into agglomerates precludes recognition of original microbial textures and silicified microbes. Episodic fluctuations in the physico-chemical conditions of surface waters controlled the acidic hydrolysis of biomarkers. Wavy laminated fabrics from pond margins comprise fatty acids, mono- and dialkyl glycerol, mono- and diethers, monoalkyl glycerol esters and small traces of 10-methyl branched C16 and C18 fatty acids and archaeol, indicative of intergrowths of cyanobacteria, Aquificales, and sulfate reducing bacteria and methanogenic archaea. In contrast, wavy laminated fabrics from abandoned meanders and palisade laminated fabrics from ponds differ in their branched fatty acids and the presence vs. absence of bacteriohopanetetrol, reflecting different cyanobacterial contributions. δ13C values of biomarkers range from −22.7 to −32.9‰, but their values in the wavy (pond) and bubble fabrics have much wider ranges than those of the wavy (meander), palisade, and vitreous fabrics, reflecting dissolved inorganic carbon (DIC) sources and a decrease in 13C downstream outflow channels, with heavier values closer to vents and depleted values in ponds.

Environment deterioration and related fungal infection of Upper Jurassic horseshoe crabs with remarks on their exceptional preservation

2019 ◽  
Vol 516 ◽  
pp. 336-341 ◽  
Author(s):  
Błażej Błażejowski ◽  
Piotr Gieszcz ◽  
Andrew P. Shinn ◽  
Rodney M. Feldmann ◽  
Ewa Durska
Keyword(s):  
Fungal Infection ◽  
Upper Jurassic ◽  
Exceptional Preservation ◽  
Horseshoe Crabs

scholarly journals Methodology Applied for Thickness Selection and Stored Heat Evaluation in Non-producer Geothermal Wells in Order to Its Investment Rescue

2020 ◽  
pp. 91-111
Author(s):  
Alfonso Aragon- Aguilar ◽  
Georgina Izquierdo- Montalvo ◽  
Dominic A. Becerra- Serrato ◽  
Victor M. Monrroy- Mar
Keyword(s):  
Electric Energy ◽  
Geothermal Field ◽  
Geothermal Systems ◽  
Drainage Radius ◽  
Heterogeneous Behavior ◽  
Water Recharge ◽  
Geothermal Wells ◽  
Using Data ◽  
Heat Calculation ◽  
Heat Store

An assessment methodology of stored heat in rock formation surrounding to wellbore in geothermal systems is shown. Due to geothermal systems generally are nested in volcanic rock, it is characteristic its heterogeneous behavior. Proposed methodology starts since zone selection with possibilities of heat store. This methodology is focused to be applied in geothermal reservoirs with tendency to production decline, due to low permeability and unbalance between exploitation and water recharge. Because the high costs of drilling geothermal wells, methodology shown in this work is proposed to be applied in those with production decline or non-producers, in order to rescue its investment. The objective is to select the thickness with heat, evaluate its storage, design the appropriate instrumentation for its recovery, its energy conversion and rescue its investment done. The different designs for energy recovery using non-conventional methods to those, used habitually are reviewed. Each one of the variables for stored heat calculation was determined using technical tools of reservoir engineering. A parametric analysis about variables sensitivity (porosity and drainage radius) for determining thermal energy and corresponding electric energy of analyzed rock volume is done. Practical application of this methodology was carried out using data of one of wells of Los Humeros Mexican geothermal field.

scholarly journals Geochemical Modeling of Scale Formation due to Cooling and CO2-degassing in San Kamphaeng Geothermal Field, Northern Thailand

2021 ◽  
Vol 20 (3) ◽  
Author(s):  
Sutthipong Taweelarp ◽  
Supanut Suntikoon ◽  
Thaned Rojsiraphisal ◽  
Nattapol Ploymaklam ◽  
Schradh Saenton
Keyword(s):  
Carbon Dioxide ◽  
Hot Springs ◽  
Hot Spring ◽  
Geochemical Modeling ◽  
Chemical Properties ◽  
Geothermal Field ◽  
Spring Water ◽  
Northern Thailand ◽  
Scaling Potential ◽  
Co2 Degassing

Scaling in a geothermal piping system can cause serious problems by reducing flow rates and energy efficiency. In this work, scaling potential of San Kamphaeng (SK) geothermal energy, Northern Thailand was assessed based on geochemical model simulation using physical and chemical properties of hot spring water. Water samples from surface seepage and groundwater wells, analyzed by ICP-OES and ion chromatograph methods for chemical constituents, were dominated by Ca-HCO3 facies having partial pressure of carbon dioxide of 10–2.67 to 10–1.75 atm which is higher than ambient atmospheric CO2 content. Surface seepage samples have lower temperature (60.9°C) than deep groundwater (83.1°C) and reservoir (127.1°C, based on silica geothermometry). Geochemical characteristics of the hot spring water indicated significant difference in chemical properties between surface seepage and deep, hot groundwater as a result of mineral precipitation along the flow paths and inside well casing. Scales were mainly composed of carbonates, silica, Fe-Mn oxides. Geochemical simulations based on multiple chemical reaction equilibria in PHREEQC were performed to confirm scale formation from cooling and CO2-degassing processes. Simulation results showed total cumulative scaling potential (maximum possible precipitation) from 267-m deep well was estimated as 582.2 mg/L, but only 50.4% of scaling potential actually took place at SK hot springs. In addition, maximum possible carbon dioxide outflux to atmosphere from degassing process in SK geothermal field, estimated from the degassing process, was 6,960 ton/year indicating a continuous source of greenhouse gas that may contribute to climate change. Keywords: Degassing, Geochemical modeling, PHREEQC, San Kamphaeng Hot Springs, Scaling

Using precise CA-TIMS ages of volcanic air-fall tuff beds in correlating the Walloon Coal Measures of the Surat Basin, Australia

2017 ◽  
Vol 57 (2) ◽  
pp. 810 ◽  
Author(s):  
Carmine Wainman ◽  
Peter McCabe
Keyword(s):  
High Precision ◽  
Sedimentary Facies ◽  
Time Frame ◽  
Upper Jurassic ◽  
Marine Strata ◽  
Stratigraphic Framework ◽  
Lithostratigraphic Units ◽  
Spectrometry Technique ◽  
Discontinuous Nature ◽  
Coal Measures

The Upper Jurassic Walloon Coal Measures of the Surat Basin is one of Australia’s largest and most productive gas provinces. Despite the drilling of over 8500 wells and numerous publications, the stratigraphic framework is poorly defined. The laterally discontinuous nature of the sedimentary facies, including coals and fluvial channel sandstones, makes correlation difficult. The abundance of volcanic air-fall tuff beds within strata across the basin provides a unique opportunity to independently verify existing stratigraphic frameworks. Using the high-precision chemical abrasion thermal ionisation mass spectrometry technique, zircon grains from 28 tuff beds have been successfully dated within an error margin of less than 100 kyr. These dates substantially revise biostratigraphic and lithostratigraphic frameworks. Lithostratigraphic units are diachronous across the basin. In addition, the sparsity of key spore–pollen taxa limits the application of biostratigraphy. The complex interplay of climate and subsidence on facies distributions can now be documented over a time frame of ~4 Ma. Syntectonism played an important role in variable palaeodrainage patterns across the basin, the frequency of fluvial avulsions and preferential sites of peat accumulation through time. The new stratigraphic framework should aid in future exploration for coal seam gas in the area. Dating tuff beds using high-precision dating techniques should also assist in correlation of non-marine strata elsewhere in the world.

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