scholarly journals Fault-Related Controls on Upward Hydrothermal Flow: An Integrated Geological Study of the Têt Fault System, Eastern Pyrénées (France)

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Audrey Taillefer ◽  
Roger Soliva ◽  
Laurent Guillou-Frottier ◽  
Elisabeth Le Goff ◽  
Guillaume Martin ◽  
...  
Keyword(s):  
Hot Springs ◽  
Geothermal Gradient ◽  
High Elevation ◽  
Fault Zones ◽  
Hydrothermal Systems ◽  
Crystalline Rocks ◽  
Fault System ◽  
Hydrogeological Model ◽  
Eastern Pyrenees ◽  
Hydrothermal Flow

The way faults control upward fluid flow in nonmagmatic hydrothermal systems in extensional context is still unclear. In the Eastern Pyrénées, an alignment of twenty-nine hot springs (29°C to 73°C), along the normal Têt fault, offers the opportunity to study this process. Using an integrated multiscale geological approach including mapping, remote sensing, and macro- and microscopic analyses of fault zones, we show that emergence is always located in crystalline rocks at gneiss-metasediments contacts, mostly in the Têt fault footwall. The hot springs distribution is related to high topographic reliefs, which are associated with fault throw and segmentation. In more detail, emergence localizes either (1) in brittle fault damage zones at the intersection between the Têt fault and subsidiary faults or (2) in ductile faults where dissolution cavities are observed along foliations, allowing juxtaposition of metasediments. Using these observations and 2D simple numerical simulation, we propose a hydrogeological model of upward hydrothermal flow. Meteoric fluids, infiltrated at high elevation in the fault footwall relief, get warmer at depth because of the geothermal gradient. Topography-related hydraulic gradient and buoyancy forces cause hot fluid rise along permeability anisotropies associated with lithological juxtapositions, fracture, and fault zone compositions.

Thermal groundwater movement and radionuclide transport in SW England

1985 ◽  
Vol 49 (351) ◽  
pp. 289-299 ◽  
Author(s):  
E. M. Durrance ◽  
M. J. Heath
Keyword(s):  
Hot Springs ◽  
Geothermal Gradient ◽  
Fault System ◽  
Fracture Permeability ◽  
Groundwater Movement ◽  
Main Requirement ◽  
Fracture Systems ◽  
Groundwater Circulation ◽  
High Concentrations ◽  
The Uk

AbstractHeat flow in SW England is well above average for the UK as a whole, but northwards towards Bath and Bristol the values decrease rapidly. However, hot springs occur both in the Bath-Bristol area and in mines in Cornwall. The development of hydrothermal circulation systems is thus not controlled entirely by geothermal gradient: the presence of a suitable fracture permeability is the main requirement. The thermal ‘head’ produced, which nevertheless depends upon the temperature and volume of water in the system, theoretically can exceed local topographic heads even in areas of low geothermal gradient.Thermal groundwaters usually carry above average quantities of radioelements in solution because of the long residence times involved. 222Rn values are often particularly high. High concentrations of 222Rn in surface waters arise from the discharge of groundwater. The results of a survey of 222Rn in streams in SW England have established areas of high values which are interpreted as rising limbs of convection cells with dimensions in the order of 5–10 km.In SE Devon γ-ray spectrometry of soils shows two E.-W. belts of high activity. The northern is coincident with the faulted southern margin of the Crediton Trough, while the southern is coincident with the westerly extension of the Abbotsbury fault system. Groundwater movement along deep-seated fracture systems is considered to be the explanation of these features. The horizontal scale of the area involved suggests that a thermal rather than local topographic head is the driving force. Groundwater circulation within fractures, driven by a thermal head, may therefore occur even in areas of low geothermal gradient and should be considered when selecting waste disposal sites.

Thermochronology and REE analyses as new tools to track thermal anomaly and fluid flow along a crustal scale fault (Têt fault, French Pyrenees)

2020 ◽  
Author(s):  
Gaétan Milesi ◽  
Monié Patrick ◽  
Philippe Münch ◽  
Roger Soliva ◽  
Sylvain Mayolle ◽  
...  
Keyword(s):  
Numerical Modelling ◽  
Hot Springs ◽  
Hot Spring ◽  
Numerical Models ◽  
Hanging Wall ◽  
Damage Zone ◽  
Thermal Anomaly ◽  
Geothermal Gradient ◽  
Fault Damage Zone ◽  
Hydrothermal Flow

<p>The Têt fault is a crustal scale major fault in the eastern Pyrenees that displays about 30 hot springs along its surface trace with temperatures between 29°C and 73°C. The regional process of fluid circulation at depth has previously been highlighted by thermal numerical modelling supported by hydrochemical analyses and tectonic study. Numerical modelling suggests the presence of a strong subsurface anomaly of temperature along-fault (locally > 90°C/km), governed by topography-driven meteoric fluid upflow through the fault damage zone (advection). On the basis of this modelling, we focused our thermochronological study on 30 samples collected close and between two hot spring clusters in both the hanging wall and the footwall of the Têt fault, where the most important thermal anomaly is recorded by models. We analysed apatite using (U-Th)/He (AHe) dating combined with REE analyses on the same dated grains.</p><p>Along the fault, AHe ages are in a range of 26 to 8 Ma in the footwall and 43 and 18 Ma in the hanging wall, and only few apatite grains have been impacted by hydrothermalism near the St-Thomas hot spring cluster. By contrast, particularly young AHe ages below 6 Ma, correlated to REE depletion, are found around the Thuès-les-bains hot spring cluster. These very young ages are therefore interpreted as thermal resetting due to an important hydrothermal activity. A thermal anomaly can be mapped and appears restricted to 1 km around this cluster of hot springs, i.e. more restricted than the size of the anomaly predicted by numerical models. These results reveal that AHe dating and REE analyses can be used to highlight neo- or paleo-hydrothermal anomaly recorded by rocks along faults.</p><p>This study brings new elements to discuss the onset of the hydrothermal circulations and consequences on AHe and REE mobilisation, and suggest a strong heterogeneity of the hydrothermal flow pattern into the fault damage zone. Moreover, this study suggests that crustal scale faults adjacent to reliefs can localise narrow high hydrothermal flow and important geothermal gradient.  Besides these results, this study provides new constraints for geothermal exploration around crustal faults, as well as a discussion on the use of thermochronometers into fault damage zones. </p>

scholarly journals Linking deeply-sourced volatile emissions to plateau growth dynamics in southeastern Tibetan Plateau

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Maoliang Zhang ◽  
Zhengfu Guo ◽  
Sheng Xu ◽  
Peter H. Barry ◽  
Yuji Sano ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Growth Dynamics ◽  
High Elevation ◽  
Fault System ◽  
The Tibetan Plateau ◽  
Southeastern Tibetan Plateau ◽  
Surface Uplift ◽  
Multi Stage ◽  
Geodynamic Processes ◽  
Underlying Mechanisms

AbstractThe episodic growth of high-elevation orogenic plateaux is controlled by a series of geodynamic processes. However, determining the underlying mechanisms that drive plateau growth dynamics over geological history and constraining the depths at which growth originates, remains challenging. Here we present He-CO2-N2 systematics of hydrothermal fluids that reveal the existence of a lithospheric-scale fault system in the southeastern Tibetan Plateau, whereby multi-stage plateau growth occurred in the geological past and continues to the present. He isotopes provide unambiguous evidence for the involvement of mantle-scale dynamics in lateral expansion and localized surface uplift of the Tibetan Plateau. The excellent correlation between 3He/4He values and strain rates, along the strike of Indian indentation into Asia, suggests non-uniform distribution of stresses between the plateau boundary and interior, which modulate southeastward growth of the Tibetan Plateau within the context of India-Asia convergence. Our results demonstrate that deeply-sourced volatile geochemistry can be used to constrain deep dynamic processes involved in orogenic plateau growth.

scholarly journals THREE-DIMENSIONAL ANALYSIS OF NORMAL FAULT ZONES IN KARDIA MINE, PTOLEMAIS BASIN, NW GREECE

2016 ◽  
Vol 50 (1) ◽  
pp. 15 ◽  
Author(s):  
E. Delogkos ◽  
T Manzocchi ◽  
C. Childs ◽  
C. Sachanidis ◽  
T. Barmpas ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Normal Fault ◽  
3D Models ◽  
Fault Zones ◽  
System Structure ◽  
Open Pit ◽  
Fault System ◽  
Zone Structure ◽  
Geological Interpretation ◽  
Lignite Mine

Six normal fault zones, with throws ranging from a few meters up to 50 m, were studied within an active, open pit, lignite mine in Ptolemais. Each fault was mapped 20 times over a period of five years because at intervals of ca. 3 months working faces are taken back between 20 and 50 m exposing fresh fault outcrops for mapping.Various resolutions of photographs and structural measurements were imported into a fully georeferenced 3D structural interpretation package, resulting in aseismic scale and outcrop resolution 3D fault volume with outcrop and panoramic photographs acting as the seismic sections in equivalent seismic surveys. Low resolution 3D models for the fault system structure at mine scale and higher-resolution 3D models for the fault zone structure were produced after geological interpretation and they can be used for qualitative and quantitative analysis.

scholarly journals Audiomagnetotelluric survey at the Bañitos-Gollete geothermal area, main Andes Cordillera of San Juan, Argentina.

2019 ◽  
Author(s):  
H. BARCELONA ◽  
G. PERI ◽  
D. WINOCUR ◽  
A. FAVETTO
Keyword(s):  
Geothermal Gradient ◽  
Geothermal Field ◽  
Flow Path ◽  
Fault System ◽  
Conductive Heat ◽  
Exploration Process ◽  
Tectonic Environment ◽  
Geothermal Potential ◽  
Geologic Setting ◽  
Andes Cordillera

The present research explores the Bañitos-Gollete geothermal field located in the Frontal Andes Cordillera over the Pampean flat-slab. We carried out an audiomagnetotelluric survey in order to define the underground geoelectrical structure and to understand the link between the geothermal fluid flow path and the main geological structures. 2-D audiomagnetotelluric models suggest that the deep-rooted N-S fault system controls the geothermal flow path. We propose a conductive heat-driven system, taking into consideration the geologic setting and the supposed low geothermal gradient of this tectonic environment. The mature Na-Cl waters from Gollete and an estimated reservoir temperature of ~140ºC are consistent with this conceptual model. Further investigations are required to assess the geothermal potential of the study area, and the present work likely represents only the first but necessary step in the exploration process.

Recent and active deformation in the North Evia domain, a diffuse plate boundary between Eurasia and Aegean plates in the Western termination of the North Anatolian Fault. 

2021 ◽  
Author(s):  
Fabien Caroir ◽  
Frank Chanier ◽  
Virginie Gaullier ◽  
Julien Bailleul ◽  
Agnès Maillard-Lenoir ◽  
...  
Keyword(s):  
Fault Zone ◽  
Plate Boundary ◽  
Fault Zones ◽  
North Anatolian Fault ◽  
Fault System ◽  
Eurasian Plate ◽  
Slip Rates ◽  
The North ◽  
South West ◽  
North Aegean

<p>The Anatolia-Aegean microplate is currently extruding toward the South and the South-West. This extrusion is classically attributed to the southward retreat of the Aegean subduction zone together with the northward displacement of the Arabian plate. The displacement of Aegean-Anatolian block relative to Eurasia is accommodated by dextral motion along the North Anatolian Fault (NAF), with current slip rates of about 20 mm/yr. The NAF is propagating westward within the North Aegean domain where it gets separated into two main branches, one of them bordering the North Aegean Trough (NAT). This particular context is responsible for dextral and normal stress regimes between the Aegean plate and the Eurasian plate. South-West of the NAT, there is no identified major faults in the continuity of the NAF major branch and the plate boundary deformation is apparently distributed within a wide domain. This area is characterised by slip rates of 20 to 25 mm/yr relative to Eurasian plate but also by clockwise rotation of about 10° since ca 4 Myr. It constitutes a major extensional area involving three large rift basins: the Corinth Gulf, the Almiros Basin and the Sperchios-North Evia Gulf. The latter develops in the axis of the western termination of the NAT, and is therefore a key area to understand the present-day dynamics and the evolution of deformation within this diffuse plate boundary area.</p><p>Our study is mainly based on new structural data from field analysis and from very high resolution seismic reflexion profiles (Sparker 50-300 Joules) acquired during the WATER survey in July-August 2017 onboard the R/V “Téthys II”, but also on existing data on recent to active tectonics (i.e. earthquakes distribution, focal mechanisms, GPS data, etc.). The results from our new marine data emphasize the structural organisation and the evolution of the deformation within the North Evia region, SW of the NAT.</p><p>The combination of our structural analysis (offshore and onshore data) with available data on active/recent deformation led us to define several structural domains within the North Evia region, at the western termination of the North Anatolian Fault. The North Evia Gulf shows four main fault zones, among them the Central Basin Fault Zone (CBFZ) which is obliquely cross-cutting the rift basin and represents the continuity of the onshore Kamena Vourla - Arkitsa Fault System (KVAFS). Other major fault zones, such as the Aedipsos Politika Fault System (APFS) and the Melouna Fault Zone (MFZ) played an important role in the rift initiation but evolved recently with a left-lateral strike-slip motion. Moreover, our seismic dataset allowed to identify several faults in the Skopelos Basin including a large NW-dipping fault which affects the bathymetry and shows an important total vertical offset (>300m). Finally, we propose an update of the deformation pattern in the North Evia region including two lineaments with dextral motion that extend southwestward the North Anatolian Fault system into the Oreoi Channel and the Skopelos Basin. Moreover, the North Evia Gulf domain is dominated by active N-S extension and sinistral reactivation of former large normal faults.</p>

INTERACTION: INTeraction between lifE, Rifting And Caldera Tectonics In OkataiNa

2021 ◽  
Author(s):  
Cécile Massiot ◽  
Craig Miller ◽  
Matthew Stott ◽  
Pilar Villamor ◽  
Hiroshi Asanuma ◽  
...  
Keyword(s):  
Hot Springs ◽  
Microbial Community Composition ◽  
Volcanic Eruptions ◽  
Economic Benefits ◽  
Hydrothermal Systems ◽  
Seismic Hazards ◽  
Geothermal Resources ◽  
Ongoing Research ◽  
Scientific Drilling ◽  
Drill Cores

<p>Calderas are major volcanic features with large volcanic and seismic hazards. They also host diverse microbiota, provide heat, energy, mineral and economic benefits. Despite their scientific and socio-economic importance, we still do not completely understand calderas and the interactions between volcanism, tectonism, fluid circulation and the deep biosphere because in-situ and subsurface observations are sparse.</p><p>The Okataina Volcanic Centre (OVC) in Aotearoa New Zealand, is one of two active giant calderas of the Taupō Volcanic Zone within the rapidly extending continental intra-arc Taupō Rift. This superb natural laboratory has: 1) numerous past eruptions of varied size and style, 2) documented co-eruptive earthquakes, 3) vigorous hydrothermal manifestations, 4) diverse microbial communities in hot springs but unknown in the subsurface.</p><p>We propose to establish a scientific drilling programme at the OVC to address:</p><ul><li>What are the conditions leading to volcanic eruptions; and volcano-tectonic feedbacks in intra-rift calderas?</li> <li>What controls fluid circulations in active calderas/rift regions?</li> <li>Does subsurface microbial community composition vary with tectonic and/or volcanic activity?</li> </ul><p>High temperatures complicate drillhole design, restrict data collection and prevent exploration of the biosphere. By targeting the cooler parts of the caldera, this project will use conventional engineering to maximise sampling (drill cores and fluids), downhole logging and establish long-term observatories.</p><p>Two preliminary drill targets are suggested: (1) in the centre of the caldera; (2) through the caldera margin. Drill data will provide a comprehensive record of past activity, establishing eruption frequency-magnitude relationships and precursors. Combined with well-known fault rupture history, the relative timing of tectonic and magmatic activity will be untangled. Drill data will unravel the relationships between the groundwater and hydrothermal systems, magma, faults and stress, informing thermo-hydro-mechanical regional caldera models with findings applicable worldwide. Drill cores and a dedicated fluid sampler triggered by nearby earthquakes will reveal the composition, function and potential change of microbial activity in response to rock and fluid variations.</p><p>The programme is informed by indigenous Māori, regulatory authorities and emergency managers to ensure scientific, cultural, regulatory and resilience outcomes. The programme will underpin 1) community resilience to volcanic and seismic hazards; 2) sustainable management of groundwater and geothermal resources, and 3) understanding of subsurface microbial diversity, function and geobiological interactions. At these early stages of planning, we invite the scientific community to contribute to the concept of this project in the exceptional OVC settings and strengthen linkages with other ongoing research and scientific drilling programmes.</p>

scholarly journals Fingerprinting molecular and isotopic biosignatures on different hydrothermal scenarios of Iceland, an acidic and sulfur-rich Mars analog

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Laura Sánchez-García ◽  
Daniel Carrizo ◽  
Antonio Molina ◽  
Victoria Muñoz-Iglesias ◽  
María Ángeles Lezcano ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Isotopic Composition ◽  
Hot Springs ◽  
Hydrothermal Systems ◽  
Extraterrestrial Life ◽  
High Sulfur Content ◽  
Life On Mars ◽  
Geothermal Alteration ◽  
Mars Analog ◽  
Mineralogical Assemblage

AbstractDetecting signs of potential extant/extinct life on Mars is challenging because the presence of organics on that planet is expected to be very low and most likely linked to radiation-protected refugia and/or preservative strategies (e.g., organo-mineral complexes). With scarcity of organics, accounting for biomineralization and potential relationships between biomarkers, mineralogy, and geochemistry is key in the search for extraterrestrial life. Here we explored microbial fingerprints and their associated mineralogy in Icelandic hydrothermal systems analog to Mars (i.e., high sulfur content, or amorphous silica), to identify potentially habitable locations on that planet. The mineralogical assemblage of four hydrothermal substrates (hot springs biofilms, mud pots, and steaming and inactive fumaroles) was analyzed concerning the distribution of biomarkers. Molecular and isotopic composition of lipids revealed quantitative and compositional differences apparently impacted by surface geothermal alteration and environmental factors. pH and water showed an influence (i.e., greatest biomass in circumneutral settings with highest supply and turnover of water), whereas temperature conditioned the mineralogy that supported specific microbial metabolisms related with sulfur. Raman spectra suggested the possible coexistence of abiotic and biomediated sources of minerals (i.e., sulfur or hematite). These findings may help to interpret future Raman or GC–MS signals in forthcoming Martian missions.

Geothermal gradients in the Hinton area of west-central Alberta

1982 ◽  
Vol 19 (4) ◽  
pp. 755-766 ◽  
Author(s):  
H. L. Lam ◽  
F. W. Jones ◽  
C. Lambert
Keyword(s):  
Hot Springs ◽  
Rocky Mountain ◽  
Geothermal Gradient ◽  
Temperature Data ◽  
Petroleum Exploration ◽  
Well Logs ◽  
Thermal Gradients ◽  
Disturbed Region ◽  
West Central ◽  
Exploration Well

Temperature data from petroleum exploration well logs of 3360 wells in a region of west-central Alberta are used to estimate thermal gradients. A relatively high geothermal gradient (~36 °C/km) of oblong shape located near Hinton is observed. The axis of the anomaly strikes approximately southwest–northeast and passes through the Miette Hot Springs area. It appears that water is heated at depth in the Rocky Mountain disturbed region and travels eastward and toward the surface along fault planes.

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