Mineralogy and geochemistry of rare earth elements in the Moyil Valley alteration zones, Meshkinshahr (northwest Iran)

Abstract Sabalan Mountain (northwest Iran) witnessed intense volcanic activity during the Cenozoic (Plio-Pleistocene). The result of this manifests itself in the conical geometry of the Sabalan stratovolcano and ahigh hydrothermal gradient around it, which can be detected by geological phenomena such as hot springs, smoke gases and steam outlet pores. The high hydrothermal slope and upward migration of hot water in this area have caused extensive alteration zones in the host rocks. A mineralogical study of alteration zones in thewells drilled in the Moyil Valley to the northwest of Sabalan Mountain has revealed the presence of phyllic, argillic, calcitic and propylitic alterations in volcanic rocks (trachyandesite) and alteration phyllic and propylitic ones in monzonite rocks. In chondrite-normalised rare-earth-element diagrams, trachyandesite rocks exhibit an HREEs enrichment when compared to MREEs and LREEs in propylitic and calcitic alteration zones. This result can be explained by the acidic nature of hydrothermal fluids containing complex ions such as (SO-2, Cl-). The (La/Yb)cn, (La/Sm)cn and (Tb/Yb)cn ratios for argillic, phyllic, propylitic and calcitic alteration zones have revealed that they are higher in fresh rocks compared to altered rocks, suggesting the enrichment of HREEs in comparison to LREEs and MREEs. The anomalies of Eu do not change remarkably in the argillic and propylitic alteration zones of trachyandesite rocks; apparently, alteration hadno effect on them. Such behaviour reflects the presence of gold cations in Eu+3 formed at temperatures below 250°C. Eu anomalies increased in propylitic alteration zones in monzonite rocks and calciticand phyllic alteration zones in trachyandesiterocks.

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PROMINE

PROMINE ◽

10.33019/promine.v5i2.918 ◽

2017 ◽

Vol 5 (2) ◽

pp. 48-53

Author(s):

Andi Faesal ◽

Arifudin Idrus ◽

Djoko Wintolo

Keyword(s):

Magnetic Anomaly ◽

Porphyry Copper ◽

Volcanic Rocks ◽

Magnetic Anomalies ◽

Alteration Zone ◽

Alteration Zones ◽

Propylitic Alteration ◽

Oxide Minerals ◽

Mineral Sulfides ◽

The Village

The research sites are located in the village of Berambang, Sekotong District, West Lombok Regency,West Nusa Tenggara Province. This area was dominated by volcanic rocks composed of dasiticvolcanic rock, diatrema breccia, and diorite intrusion. Berambang area shows alteration in the form ofpotassic, propylitic, advanced argillic, and argillic alterations where in some places accompanied bypyritisation and stockwork structure, the type of mineralization in this area is a porphyry copper-goldtype. In the potasic alteration zone there are minerals that have a strong anomaly response to themagnetic due to the presence of oxide minerals magnetite (Fe2O3). Mineral sulfides such as pyrite(FeS2) and chalcopyrite (CuFeS2) will also provide significant anomalous responses that have anabundance of 2-5% in the potassic zone. In a propylitic alteration zone characterized by chlorite,calcite and epidote minerals that do not respond to magnetic anomalies, the presence of pyriteminerals, hematites and chalcopyrite with abundance of ≤1% will provide some magnetic anomaly inthe propylitic zone. As for advanceargillic alteration zones characterized by mineral andalusite, aluniteand quartz, there will not be any magnetic anomalies, the phenomena was due to the rarity ofmineralization in this zone gives an insignificant anomalous impact. Meanwhile, for the argillic zonecharacterized by mineral illite, kaolinite and smectite will not have anomalous magnetic impact, veryrare mineralization in the argillic zone so that the magnetic anomaly is not significant. From the floatingEuler 3D shows an anomalous source from a depth of 0 meters to a depth of more than 400 meters.

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Origin of the low-medium temperature hot springs around Nanjing, China

Open Geosciences ◽

10.1515/geo-2020-0269 ◽

2021 ◽

Vol 13 (1) ◽

pp. 820-834

Author(s):

Jun Ma ◽

Zhifang Zhou

Keyword(s):

Hot Springs ◽

Hot Spring ◽

Hot Water ◽

Geothermal Water ◽

Geological Condition ◽

Medium Temperature ◽

Rock Interaction ◽

Karst Landform ◽

Karst Landforms ◽

Development And Management

Abstract The exploration of the origin of hot spring is the basis of its development and utilization. There are many low-medium temperature hot springs in Nanjing and its surrounding karst landform areas, such as the Tangshan, Tangquan, Lunshan, and Xiangquan hot springs. This article discusses the origin characters of the Lunshan hot spring with geological condition analysis, hydrogeochemical data, and isotope data. The results show that the hot water is SO4–Ca type in Lunshan area, and the cation content of SO4 is high, which are related to the deep hydrogeological conditions of the circulation in the limestone. Carbonate and anhydrite dissolutions occur in the groundwater circulation process, and they also dominate the water–rock interaction processes in the geothermal reservoir of Lunshan. The hot water rising channels are deeply affected by the NW and SN faults. Schematic diagrams of the conceptual model of the geothermal water circulation in Lunshan are plotted. The origin of Tangshan, Tangquan, and Xiangquan hot springs are similar to the Lunshan hot spring. In general, the geothermal water in karst landforms around Nanjing mainly runs through the carbonate rock area and is exposed near the core of the anticlinal structure of karst strata, forming SO4–Ca/SO4–Ca–Mg type hot spring with the water temperature less than 60°C. The characters of the hot springs around Nanjing are similar, which are helpful for the further research, development, and management of the geothermal water resources in this region.

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Nisyros Volcanic Island: A Geosite through a Tailored GIS Story

Geosciences ◽

10.3390/geosciences11030132 ◽

2021 ◽

Vol 11 (3) ◽

pp. 132

Author(s):

Varvara Antoniou ◽

Paraskevi Nomikou ◽

Dimitrios Panousis ◽

Effrosyni Zafeirakopoulou

Keyword(s):

Spatial Data ◽

Hot Springs ◽

Volcanic Rocks ◽

Data Communication ◽

Aegean Sea ◽

Volcanic Island ◽

Eastern Aegean ◽

Strongly Connected ◽

Historical Heritage ◽

Available Information

The volcanic island of Nisyros (Greece) is here presented as it presents unique characteristics being a Quaternary volcano in the eastern Aegean Sea, composed of volcanic rocks, and featuring a central caldera that is surrounded by volcanic domes and thick lavas. Its history is strongly connected to the volcano impressing the visitors with steaming hydrothermal craters, intensive smell of sulfur and fumarolic gases, and hot springs. Due to its morphology and geographical position, its cultural and historical heritage has been unchanged in time, bequeath to the island plenty of churches, monasteries with hagiographic frescoes, castles, caves, and spas. To present the geodiversity, the cultural environment, and the biodiversity of this geosite, a relatively new geographic approach was used, ESRI Story Maps. Being web-based applications, they are widespread as an interactive responsive tool used for spatial data communication and dissemination, by combining thematic 2D and 3D webmaps, narrative text, and multimedia content. Such applications can be an ideal way for presenting the available information of places characterized as geosites or protected areas worldwide, providing quick access to the available information to a broader, non-technical audience, developing the interest, and possibly motivating the public to learn more or visit them.

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Vulcânicas potássicas intemperizadas como protólitos dos filitos hematíticos da Serra do Espinhaço Meridional (Minas Gerais)

Geochimica Brasiliensis ◽

10.21715/gb2358-2812.2020342183 ◽

2020 ◽

Vol 34 (2) ◽

pp. 183-194

Author(s):

Alexandre Chaves ◽

Luiz Knauer

Keyword(s):

Rare Earth ◽

Rare Earth Elements ◽

Volcanic Rocks ◽

Alkaline Rock ◽

Major Elements ◽

Volcanic Origin ◽

Espinhaço Range ◽

Weathering Processes ◽

Igneous Layering ◽

Hematitic Phyllite

The hematitic phyllite is a rock that occurs in the São João da Chapada and Sopa-Brumadinho formations of the southern Espinhaço range. Its origin is widely discussed in papers on Espinhaço, but there is no consensus on its protolith due to certain characteristics of the lithotype, such as its chemical composition and textural features. The pattern of rare earth elements strongly enriched [(La/Yb)N 6.80-17.68], with light rare earth elements [(La/Sm)N 2.54-4.83] richer than heavy ones [(Gd/Yb)N 1.28-3,32], suggests that the protolith was an alkaline volcanic rock formed during the rift that generated the Espinhaço basin. The major elements indicate that the alkaline rock met weathering processes, becoming a regolith. During the Brasiliano metamorphism, it finally became hematitic phyllite. Other characteristics of the lithotype, such as the presence of sericite-bearing rounded parts (possibly formed by alteration and deformation of leucite crystals) and the preservation of igneous layering, suggest a potassic volcanic origin for hematitic phyllite. In diagram that allows identifying altered and metamorphic volcanic rocks, the investigated samples have composition similar to a feldspathoid-rich alkali-basalt, probably a leucite tephrite, a leucitite or even a lamproite, rocks from mantle source.

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Petrogenesis of the Upper Cretaceous volcanism in the Kefken region, Western Pontides, NW Turkey

10.5194/egusphere-egu21-5108 ◽

2021 ◽

Author(s):

Turgut Duzman ◽

Ezgi Sağlam ◽

Aral I. Okay

Keyword(s):

Rare Earth ◽

Rare Earth Elements ◽

Partial Melting ◽

Upper Cretaceous ◽

Volcanic Rocks ◽

Early Eocene ◽

Heavy Rare Earth ◽

Heavy Rare Earth Elements ◽

Cretaceous Volcanism ◽

Oceanic Slab

The Upper Cretaceous volcanic and volcaniclastic rocks crop out along the Black Sea coastline in Turkey. They are part of a magmatic arc that formed as a result of northward subduction of the Tethys ocean beneath the southern margin of Laurasia. The lower part of the Upper Cretaceous volcanism in the Kefken region, 100 km northeast of Istanbul, is represented by basaltic andesites, andesites, agglomerates and tuffs, which have yielded Late Cretaceous (Campanian, ca. 83 Ma) U-Pb zircon ages. The volcanic and volcanoclastic rocks are stratigraphically overlain by shallow to deep marine limestones, which range in age from Late Campanian to Early Eocene.&#160; Geochemically, basaltic andesites and andesites display negative anomalies in Nb, Ta and Ti, enrichment in large ion lithophile elements (LILE) relative to high field strength elements (HFSE). Light rare earth elements (LREE) show slightly enrichment relative to heavy rare earth elements (Lacn/Ybcn =2.51-3.63) and there are slight negative Eu anomalies (Eu/Eu* = 0.71-0.95) in basaltic andesite and andesite samples. The geochemical data indicate that Campanian volcanic rocks were derived from the partial melting of the mantle wedge induced by hydrous fluids released by dehydration of the subducted oceanic slab.There is also a horizon of volcanic rocks, about 230 m thick, within the Late Campanian-Early Eocene limestone sequence.&#160; This volcanic horizon, which consists of pillow basalts, porphyritic basalts,&#160; andesites and dacites, is of Maastrichtian age based on paleontological data from the intra-pillow sediments and U-Pb zircon ages from the andesites and dacites (72-68 Ma).&#160; The Maastrichtian andesites and dacites are geochemically distinct from the Campanian volcanic rocks. They show distinct adakite-like geochemical signatures with high ratios of Sr/Y (>85.5), high Lacn/Ybcn (16.4-23.7) ratios, low content of Y (7.4-8.6 ppm) and low content of heavy rare-earth elements (HREE). The adakitic rocks most probably formed as a result of partial melting of the subducting oceanic slab under garnet and amphibole stable conditions.The Upper Cretaceous arc sequence in the Kefken region shows a change from typical subduction-related magmas to adakitic ones, accompanied by decrease in the volcanism.&#160;&#160;

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Geochemistry and petrogenesis of the early Proterozoic Hemlock volcanic rocks and the Kiernan sills, southern Lake Superior region

Canadian Journal of Earth Sciences ◽

10.1139/e88-052 ◽

1988 ◽

Vol 25 (4) ◽

pp. 528-546 ◽

Cited By ~ 9

Author(s):

W. C. Ueng ◽

T. P. Fox ◽

D. K. Larue ◽

J. T. Wilband

Keyword(s):

Trace Elements ◽

Rare Earth ◽

North Atlantic ◽

North Atlantic Ocean ◽

Lake Superior ◽

Volcanic Rocks ◽

Wall Rock ◽

Major Elements ◽

Chemical Contamination ◽

Early Proterozoic

During the early Proterozoic, the 2 km thick differentiated gabbroic Kiernan sills were emplaced into a thick accumulation of pillow basalt and associated deep-water strata, the Hemlock Formation, in the southern Lake Superior region. On the basis of major elements and trace elements (including rare-earth-element data), the Kiernan sills and the hosting volcanic rocks of the Hemlock Formation were determined to be comagmatic in origin, and both evolved from assimilation – crystal fractionation processes. The major assimilated components in these igneous rocks are identified as terrigenous sedimentary rocks. Assimilation affected the abundance of Nb, Ta, light rare-earth elements, and most likely P, Rb, Th, and K in the magma. The effect of chemical contamination from wall-rock assimilation accumulates with increasing differentiation.With wall-rock contamination carefully evaluated, a series of tectonic discriminating methods utilizing immobile trace elements indicates that the source magma was a high-Ti tholeiitic basalt similar to present-day mid-ocean-ridge basalts (MORB). It is suggested from this study that most of the enriched large-ion lithophile elements and LREE of the magma were not inherited from the mantle but from assimilation of supracrustal rocks. Chemical signatures of these rocks are distinctively different from those of arc-related volcanics. A rifting tectonic regime analogous to the opening of the North Atlantic Ocean and extrusion of North Atlantic Tertiary volcanics best fits the criteria revealed by this study.

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THE EFFECT OF BETA-DECAY ON THE EXCHANGE PROPERTIES OF THE RARE EARTH–EDTA COMPLEX IONS

Canadian Journal of Chemistry ◽

10.1139/v61-129 ◽

1961 ◽

Vol 39 (5) ◽

pp. 1049-1053 ◽

Cited By ~ 7

Author(s):

P. Glentworth ◽

R. H. Betts

Keyword(s):

Rare Earth ◽

Metal Ion ◽

Chemical Reactivity ◽

Sudden Change ◽

Chelating Agent ◽

Beta Particle ◽

Central Metal ◽

Complex Ions ◽

Rare Earth Ion ◽

The Rare Earth

It is shown that the rare earth ion Yb3+ is very resistant towards ordinary thermal exchange when it is complexed with the chelating agent EDTA in aqueous solution. However, when the complexed rare earth atom, as the 1.8-h Yb-177, emits a beta-particle, the daughter atom Lu-177 escapes readily from the chelate structure. Nuclear recoil arising from the beta-particle emission is shown not to be the cause of the escape of the daughter atom. It is suggested that the observed lability of the daughter atom is a result of a high degree of chemical reactivity of the chelate ion arising from the sudden change in atomic number of the central metal ion of the chelate structure.

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Eocene Challis-Kamloops volcanism in central British Columbia: an example from the Buck Creek basin

Canadian Journal of Earth Sciences ◽

10.1139/e98-040 ◽

1998 ◽

Vol 35 (8) ◽

pp. 951-963 ◽

Cited By ~ 14

Author(s):

J Dostal ◽

D A Robichaud ◽

B N Church ◽

P H Reynolds

Keyword(s):

British Columbia ◽

Rare Earth ◽

Rare Earth Element ◽

Fractional Crystallization ◽

Earth Element ◽

Volcanic Rocks ◽

Volcanic Belt ◽

The United States ◽

Calc Alkaline ◽

Heavy Rare Earth Element

Eocene volcanic rocks of the Buck Creek basin in central British Columbia are part of the Challis-Kamloops volcanic belt extending from the United States across British Columbia to central Yukon. The volcanic rocks include two units, the Buck Creek Formation, composed of high-K calc-alkaline rocks with predominant andesitic composition, and the overlying Swans Lake unit made up of intraplate tholeiitic basalts. Whole rock 40Ar/39Ar data for both units show that they were emplaced at 50 Ma. They have similar mantle-normalized trace element patterns characterized by a large-ion lithophile element enrichment and Nb-Ta depletion, similar chondrite-normalized rare earth element patterns with (La/Yb)n ~4-14 and heavy rare earth element fractionation, and overlapping epsilonNd values (2.4-3.1) and initial Sr-isotope ratios ( ~ 0.704). These features suggest derivation of these two units from a similar mantle source, probably garnet-bearing subcontinental lithosphere. The differences between tholeiitic and calc-alkaline suites can be due, in part, to differences in the depth of fractional crystallization and the crystallizing mineral assemblage. Fractional crystallization of the calc-alkaline magmas began at a greater (mid-crustal) depth and included fractionation of Fe-Ti oxides. The volcanic rocks are probably related to subduction of the Farallon plate under the North American continent in a regime characterized by transcurrent movements and strike-slip faulting.

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Water, Life and Geology

10.5194/egusphere-egu2020-10127 ◽

2020 ◽

Author(s):

ines freyssinel

Keyword(s):

Hot Springs ◽

Marine Organism ◽

Field Trips ◽

Water Levels ◽

Hot Water ◽

Eastern Africa ◽

Tectonic Activity ◽

Unequal Distribution ◽

Geothermal Activity ◽

Water Springs

In Geology, water plays a major role in the transformation of landscapes. Hot water springs can be exploited as geothermic resources. The first forms of life on Earth, cyanobacteria, lived in water. I studied these three examples with my students, implementing various educational strategies: field trips, academic conferences, and hands-on activities.Example 1-Fields trips In Marseille, I organised a geological outing in the Calanques, the protected rocky coves, which explains the geological history of the region as well and erosion and sedimentation phenomena. The Calanques are made of limestone rocks that were formed by the accumulation of marine organism skeletons at the bottom of a warm sea during the Secondary Era. During the Cretaceous period, the calcareous rocks were pushed to the surface through the tectonic trust and overlapping of the African and European plates. The topography formed (The Provencal and Pyrenean chain and its foothills) undergoes weathering, fractures and distorts under the action of water. The hot rainy periods allow chemical dissolution and facilitates the formation of karstic networks. The periods of glaciation during the quaternary provoke declining water levels and sculpted furthermore the ground thanks to glacial action. In Eastern Africa, in Djibouti, exceptional field trips were possible with the students&#160; to the sites of the Assal-Goubbhet lake. It is a place like no other, a large depression 150 meters under the sea level.We studied the specific hydrological exchanges which explain the water hypersalinization. We measured the elevated thermal flows of the hot-water springs and linked our findings to tectonic activity. Example 2 - Lab activity with stromatolites.Water and the first Life forms.The 3.5 billion year stromatolites are bio-constructed and sedimentary rocks. They bear witness to the presence of life forms in the oceans, cyanobacteria. An exploration of the terrain and a practical session enabled the students to discover the action of these living organisms on the primal atmosphere and grasp the concept of Actualism in Geology. Example 3 - Conference, field trip, and practical activities on geothermal activity.Djibouti aims to become self-sufficient in energy by 2035 thanks to the production of 100% renewable electricity. The country relies on geothermal energy to reach that goal. We therefore studied this theme with the students of the French Highschool. Outings permitted to photograph the hot springs. Rain water infiltrates the ground and heats when in contact with the magma chambers less than 4 km under our feet. Through rock crack cause by earthquakes, the water comes to the surface in the form of steam and concentrates in the hot springs.These examples remind our students of the essential role of water on our planet and its unequal distribution as a source of life, as a factor in the transformation of the landscapes or as a vital energy source.

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Evolution of deep mantle sourced carbonated melt in the mantle lithosphere

10.5194/egusphere-egu2020-13055 ◽

2020 ◽

Author(s):

Guoliang Zhang

Keyword(s):

Rare Earth ◽

Field Strength ◽

Rare Earth Elements ◽

Lithospheric Mantle ◽

High Field ◽

Volcanic Rocks ◽

Mantle Lithosphere ◽

High Field Strength ◽

Alkali Basalts ◽

Deep Mantle

Deep sourced magmas play a key role in distribution of carbon in the Earth&#8217;s system. Oceanic hotspots rooted in deep mantle usually produce CO2-rich magmas. However, the association of CO2 with the origin of these magmas remains unclear. Here we report geochemical analyses of a suite of volcanic rocks from the Caroline Seamount Chain formed by the deep-rooted Caroline hotspot in the western Pacific. The most primitive magmas have depletion of SiO2 and high field strength elements and enrichment of rare earth elements that are in concert with mantle-derived primary carbonated melts. The carbonated melts show compositional variations that indicate reactive evolution within the overlying mantle lithosphere and obtained depleted components from the lithospheric mantle. The carbonated melts were de-carbonated and modified to oceanic alkali basalts by precipitation of perovskite, apatite and ilmenite that significantly decreased the concentrations of rare earth elements and high field strength elements. These magmas experienced a stage of non-reactive fractional crystallization after the reactive evolution was completed. Thus, the carbonated melts would experience two stages, reactive and un-reactive, of evolution during their transport through in thick oceanic lithospheric mantle. We suggest that the mantle lithosphere plays a key role in de-carbonation and conversion of deep-sourced carbonated melts to alkali basalts. This work was financially supported by the National Natural Science Foundation of China (91858206, 41876040).

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