scholarly journals Tracking geothermal anomalies along a crustal fault using (U − Th)∕He apatite thermochronology and rare-earth element (REE) analyses: the example of the Têt fault (Pyrenees, France)

Solid Earth ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 1747-1771 ◽  
Author(s):  
Gaétan Milesi ◽  
Patrick Monié ◽  
Philippe Münch ◽  
Roger Soliva ◽  
Audrey Taillefer ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Element ◽  
Earth Element ◽  
Hot Springs ◽  
Hot Spring ◽  
Thermal Evolution ◽  
Hanging Wall ◽  
Damage Zone ◽  
Hydrothermal Activity ◽  
Eastern Pyrenees

Abstract. The Têt fault is a major crustal-scale fault in the eastern Pyrenees (France) along which 29 hot springs emerge, mainly within the footwall damage zone of the fault. In this study, (U-Th)/He apatite (AHe) thermochronology is used in combination with rare-earth element (REE) analyses in order to investigate the imprint of hydrothermal activity around two main hot spring clusters (Thuès-les-Bains and St Thomas) and between them. The main goal is to better define the geometry and intensity of the recent thermal anomalies along the fault and to compare them with previous results from numerical modelling. This study displays 99 new AHe ages and 63 REE analyses on single apatite grains from samples collected in the hanging wall (18 to 43 Ma) and footwall (8 to 26 Ma) of the Têt fault. In the footwall, the results reveal AHe age resetting and apatite REE depletion due to hydrothermal circulation along the Têt fault damage zone, near the two hot spring clusters, and also in areas lacking present-day geothermal surface manifestation. These age resettings and element depletions are more pronounced around the Thuès-les-Bains hot spring cluster and are spatially restricted to a limited volume of the damage zone. Outside this damage zone, new modelling of thermochronological data specifies the thermal evolution of the massifs. The footwall model suggests the succession of two main phases of cooling: between 30 and 24 Ma and a second one around 10 Ma. In the hanging wall, little evidence of hydrothermal imprint on AHe ages and REE signatures has been found, and thermal modelling records a single cooling phase at 35–30 Ma. Low-temperature thermochronology combined with REE analyses allows us to identify the spatial extent of a recent geothermal perturbation related to hydrothermal flow along a master fault zone in the eastern Pyrenees, opens new perspectives to constrain the geometry and intensity of geothermal fields, and provides new regional constraints on the cooling history of the footwall and hanging-wall massifs.

scholarly journals Tracking geothermal anomalies along a crustal fault using (U-Th)/He apatite thermochronology and REE analyses, the example of the Têt fault (Pyrenees, France)

2020 ◽  
Author(s):  
Gaétan Milesi ◽  
Patrick Monié ◽  
Philippe Münch ◽  
Roger Soliva ◽  
Audrey Taillefer ◽  
...  
Keyword(s):  
Hot Springs ◽  
Hot Spring ◽  
Hanging Wall ◽  
Regional Scale ◽  
Damage Zone ◽  
Hydrothermal Activity ◽  
Thermal Anomalies ◽  
Eastern Pyrenees ◽  
Major Fault ◽  
Surface Manifestation

Abstract. The Têt fault is a crustal scale major fault in the eastern Pyrenees along which 29 hot springs emerge mainly within the footwall damage zone of the fault. In this study, (U-Th)/He apatite (AHe) thermochronology is used in combination with REE analyses to investigate the imprint of hydrothermal activity nearby two main hot spring clusters and in between in an attempt to better define the geometry and intensity of the recent thermal anomalies along the fault and to compare them with previous results from numerical modelling. This study displays 99 new AHe ages and 63 REE analyses on samples collected in the hanging wall (18 to 43 Ma) and footwall (8 to 26 Ma) of the Têt fault. In the footwall, the results reveal AHe age resetting and apatite REE depletion due to hydrothermal circulation along the Têt fault damage zone, nearby the actual hot springs (Thuès-les-Bains and St-Thomas) but also in areas lacking actual geothermal surface manifestation. These age resetting and element depletions are more pronounced around Thuès-les-Bains hot spring cluster and are spatially restricted to a limited volume of the damage zone. Outside this damage zone, the modelling of thermochronological data in the footwall suggests the succession of two main phases of exhumation, between 30 and 24 Ma and a second one around 10 Ma. In the hanging wall, few evidences of hydrothermal imprint on AHe ages and REE signatures have been found and thermal modelling records a single exhumation phase at 35–30 Ma. Low-temperature thermochronology combined with REE analyses allows to identify the spatial distribution of a recent geothermal perturbation related to hydrothermal flow along a master fault zone in the eastern Pyrenees, opens new perspectives for the exploration of geothermal fields and provides at the regional scale new constraints on the tectonic uplift of the footwall and hanging wall massifs.

scholarly journals The long-term variations of rare earth element contents in Tamagawa hot spring waters, Akita Prefecture, Japan.

2002 ◽  
Vol 63 (2) ◽  
pp. 135-145 ◽  
Author(s):  
Tetsuya SANADA ◽  
Nobuki TAKAMATSU ◽  
Yuzo YOSHIIKE ◽  
Masayuki IMAHASHI ◽  
Hideo HIGUCHI
Keyword(s):  
Rare Earth ◽  
Rare Earth Element ◽  
Earth Element ◽  
Hot Spring ◽  
Akita Prefecture ◽  
Element Contents ◽  
Long Term Variations

scholarly journals Mineralogical and geochemical characterisation of the Kipawa syenite complex, Quebec: implications for rare-earth element deposits

2022 ◽  
Author(s):  
S Matte ◽  
M Constantin ◽  
R Stevenson
Keyword(s):  
Rare Earth ◽  
Rare Earth Element ◽  
Earth Element ◽  
Crustal Contamination ◽  
Hydrothermal Activity ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
Gneissic Granite ◽  
Icp Ms ◽  
Regional Tectonic

The Kipawa rare-earth element (REE) deposit is located in the Parautochton zone of the Grenville Province 55 km south of the boundary with the Superior Province. The deposit is part of the Kipawa syenite complex of peralkaline syenites, gneisses, and amphibolites that are intercalated with calc-silicate rocks and marbles overlain by a peralkaline gneissic granite. The REE deposit is principally composed of eudialyte, mosandrite and britholite, and less abundant minerals such as xenotime, monazite or euxenite. The Kipawa Complex outcrops as a series of thin, folded sheet imbricates located between regional metasediments, suggesting a regional tectonic control. Several hypotheses for the origin of the complex have been suggested: crustal contamination of mantle-derived magmas, crustal melting, fluid alteration, metamorphism, and hydrothermal activity. Our objective is to characterize the mineralogical, geochemical, and isotopic composition of the Kipawa complex in order to improve our understanding of the formation and the post-formation processes, and the age of the complex. The complex has been deformed and metamorphosed with evidence of melting-recrystallization textures among REE and Zr rich magmatic and post magmatic minerals. Major and trace element geochemistry obtained by ICP-MS suggest that syenites, granites and monzonite of the complex have within-plate A2 type anorogenic signatures, and our analyses indicate a strong crustal signature based on TIMS whole rock Nd isotopes. We have analyzed zircon grains by SEM, EPMA, ICP-MS and MC-ICP-MS coupled with laser ablation (Lu-Hf). Initial isotopic results also support a strong crustal signature. Taken together, these results suggest that alkaline magmas of the Kipawa complex/deposit could have formed by partial melting of the mantle followed by strong crustal contamination or by melting of metasomatized continental crust. These processes and origins strongly differ compare to most alkaline complexes in the world. Additional TIMS and LA-MC-ICP-MS analyses are planned to investigate whether all lithologies share the same strong crustal signature.

Rare-earth element distribution and genesis of manganese ores associated with Tethyan ophiolites, Iran: A review

2016 ◽  
Vol 80 (1) ◽  
pp. 127-142 ◽  
Author(s):  
Alireza Zarasvandi ◽  
Mohsen Rezaei ◽  
Martiya Sadeghi ◽  
Houshang Pourkaseb ◽  
Masoume Sepahvand
Keyword(s):  
Rare Earth ◽  
Trace Element ◽  
Rare Earth Element ◽  
Earth Element ◽  
Hydrothermal Activity ◽  
Element Distribution ◽  
Manganese Ores ◽  
Basaltic Rocks ◽  
Rare Earth Element Distribution ◽  
Manganese Deposits

AbstractThe Zagros orogenic and metallogenic belt is characterized by the widespread occurrence of manganese and ferromanganese deposits. These deposits are spatially associated with radiolarian cherts and basaltic rocks, which cap the ophiolite sequences. The present work provides a review on the rare-earth element (REE) geochemistry coupled with major- and trace-element geochemical characteristics of the Nasirabad and Abadeh Tashk manganese deposits (associated with the Neyriz ophiolite), and Sorkhvand manganese deposit (associated with the Kermanshah ophiolite). These data are used to gain an insight into the primary ore-forming processes that control the deposition of manganese ores. All of the selected manganese deposits have consistently high Ba contents and low concentrations of trace elements (Co, Cu and Ni) with high Mn/Fe ratios typical of hydrothermal activity. A relatively low REE abundance, Lan/Ndn ratios (>3), and position on a Lan/Cen vs. Al2O3/(Al2O3 + Fe2O3) discrimination plot indicate a distal hydrothermal source for almost all of the selected manganese deposits. Most of the deposits are characterized by Ceanom < –0.1 which reflects the prevailing oxidative conditions during the deposition of manganese ores. Importantly, this is consistent with the occurrence of non-sulfide oxic Mn mineralization in all the manganese deposits of the Zagros orogeny. The comparison of the Sorkhvand, Abadeh Tashk and Nasirabad manganese deposits with other manganese deposits elsewhere in the world indicates that major- and trace-element characteristics, as well as the REE composition of the Zagros manganese deposits are analogous to those typical of hydrothermal deposits.

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

&lt;p&gt;The T&amp;#234;t 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&amp;#176;C and 73&amp;#176;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 &gt; 90&amp;#176;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 T&amp;#234;t 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.&lt;/p&gt;&lt;p&gt;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 Thu&amp;#232;s-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.&lt;/p&gt;&lt;p&gt;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.&amp;#160;&amp;#160;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.&amp;#160;&lt;/p&gt;

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