Electron microprobe analyses of zeolite minerals from Neogene volcanic rocks in the Breitenbush-Austen Hot Springs area, Oregon

1996 ◽  
Author(s):  
R.L. Oscarson ◽  
K.E. Bargar
Geosciences ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 132
Author(s):  
Varvara Antoniou ◽  
Paraskevi Nomikou ◽  
Dimitrios Panousis ◽  
Effrosyni Zafeirakopoulou

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.


2020 ◽  
Vol 5 (1) ◽  
pp. 45
Author(s):  
Jeferson Polii ◽  
Alfrie Musa Rampengan

Geothermal energy depends on volcanic regions or plate subduction. Indonesia has geothermal potential due to the meeting of 3 (three) large plates. North Sulawesi is one of the areas located in the ring of fire. Some areas in the Minahasa Regency, North Sulawesi province, were targeted for research because they have manifestations of geothermal such as hot pools, steaming ground, mud pools, and other manifestations. The research location is divided into 3 (three) locations around the Lahendong geothermal area, namely the Lahendong pine forest, the Toraget hot air area, and the hot springs in the village of Totolan. The results of sample and ploting tests in ternary diagrams show that all three geothermal manifestations have sulfuric acid type fluids. This type of geothermal fluid has a high SO4 content, while HCO3 and Cl values ​​are low. Hot springs that have a type of sulfuric acid occur in active volcanic regions. This is supported by the lithology of three areas of manifestation which are composed of basalt resulting from volcanic rocks.


Geologos ◽  
2020 ◽  
Vol 26 (3) ◽  
pp. 219-231
Author(s):  
Hossain Naseri ◽  
Mahnaz Jamadi ◽  
Kaikhosrov Radmard ◽  
Ghafour Alavi

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.


Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-19
Author(s):  
Darwin Augusto Torres-Ceron ◽  
Carlos Daniel Acosta-Medina ◽  
Elisabeth Restrepo-Parra

Hot springs of the volcanic zones are characterized for having high sulfur content in the form of sulphate and other ions resulting from chemical reactions. Sources with these types of elements are of great interest for the tourism and geothermal industry because of their highlighted properties which include therapeutic treatments, relaxation baths, agricultural applications, and preservation of flora and fauna among others. For these reasons, research oriented to carry out the characterization of these factors is of great importance to determine the availability of places with such characteristics. This work shows the characterization of 17 hot spring sources located in the Coconuco and San Juan sectors (Cauca, Colombia, South America). Water samples were taken in May 2017, and laboratory analyses were carried out by the Water Laboratory at Universidad Nacional de Colombia-Manizales, based on the Standard Methods (APHA-AWWA-WEF). Rock samples were taken in November 2017, and laboratory analyses were carried out by the GMAS+ Laboratory (Bogotá, Colombia). The Piper, Stiff, and ternary (Giggenbach) diagrams were used for the classification of major ions. Mineralogy composition was determined through XRD and XRF. Results indicate that most sources are of the sulphated type according to the anions and of the calcium type according to the cations. In concordance with Giggenbach diagrams, most of the sources are immature waters and, despite their interaction with rocks, they have not achieved the equilibrium. Likewise, these sources are of heated vapor type and, considering that they consist of sulphated acid sources, it is not possible to evaluate the reservoir temperatures from Na/K cations. The low Ca2+/Mg2+ ratio in the sources indicates the lack of direct migration of fluids and the high content of Ca2+ and Mg2+ regarding Na+ and K+, which suggests that fluids possibly are mixed with cold waters rich in Ca2+ and Mg2+. From the mineralogic characterization, it was observed that volcanic rocks are composed of cristobalite and albite with TiO2, Fe2O3, and CaO traces and mineral sulfur. Metals like Cr, considered in this case as contaminants, are found in low concentrations in rocks and are not detected in these waters.


2011 ◽  
Vol 76 (1) ◽  
pp. 157-166 ◽  
Author(s):  
Bryan Keith Sell ◽  
Scott Douglas Samson

AbstractGeochemical correlation of ash-fall beds with conventional tephrochronologic methods is not feasible when original glass composition is altered. Thus, alternative correlation methods may be required. Initial studies of heavily altered Paleozoic tephra (K-bentonites) have suggested the potential for employing trace-element concentrations in apatite as ash-fall bed discriminators. To further test the utility of apatite trace-element tephrochronology, we analyzed apatite phenocrysts from unaltered volcanic rocks with an electron microprobe: nine samples from rocks erupted during the Quaternary and one sample from a rock erupted during the Paleogene. The resulting apatite trace-element data provide unique bed discriminators despite within-crystal variability. Each of the volcanic rocks studied possesses unique trends in Mg, Cl, Mn, Fe, Ce and Y concentrations in apatite. The results from this study establish an important tephrochronologic method that can be applied to nearly all portions of the Phanerozoic stratigraphic record and greatly assist development of an advanced timescale. In addition to establishing a fingerprint for a particular eruption, apatite chemistry provides useful information about the source magma.


Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2170 ◽  
Author(s):  
Chaofeng Wu ◽  
Xiangyun Hu ◽  
Guiling Wang ◽  
Yufei Xi ◽  
Wenjing Lin ◽  
...  

The geothermal zone of southeast China, which is one of the country’s known geothermal zones, contains significant natural geothermal resources. To understand the formation of geothermal resources, a magnetotelluric (MT) investigation with a site spacing of 1–2 km was carried out around the Zhangzhou Basin. The recorded MT data were processed by robust time series and remote reference processing techniques. The data analysis results revealed that two-dimensional (2-D) modeling can be used to approximately determine the electrical structure. The joint inversions of TE and TM modes have been performed after distortion decomposition. In the inversion models, a low resistivity cap of 200–800 m thickness was observed, which represented the blanketing sediments composed of Quaternary and volcanic rocks of the late Jurassic period. The presence of high resistivity above a depth of 20 km indicates the granites are widely developed in the upper and middle crust. MT measurements have revealed some deep-seated high conductive zones, which were inferred to be partially melting at depth of 8–17 km, which is likely to be reason behind the formation of higher-temperature hot springs. The results also show that there is a shallower Moho, which indicates that the heat from the upper mantle may have a big contribution to the surface heat flow. Fractures-controlled meteoric fluid circulation is the most likely explanation for the hot springs.


Author(s):  
S.M. Kuehner ◽  
D.J. Joswiak

The group of minerals classified as feldspars are among the most common rock-forming minerals in the earth’s crust. The majority of feldspar compositions fall within the ternary system NaAlSi3O8-KAlSi3O8-CaAl2Si2O8, though substitution of other elements, usually in minor amounts, is common. Described here is a naturally occurring ferric iron sanidine feldspar composition in which up to ∼70 mole% of the KAlSi3O8 molecule is replaced by KFe3+ Si3O8. It thus constitutes a new end-member feldspar composition and the data have been submitted to the Commission on New Mineral Names for evaluation.The ferric iron sanidine is found in the 1.1ma volcanic rocks of the Leucite Hills, Wyo. The composition of these lavas and plugs is unusually rich in K and Fe3+, and depleted in Al compared to typical basaltic rocks. Sanidine grains are among the last phase to crystallize in the groundmass of the rocks classified as orendites, and rarely exceed 150um in length.


1980 ◽  
Vol 43 (329) ◽  
pp. 651-658 ◽  
Author(s):  
Manfred J. van Bergen

SummaryGrandidierite has been identified in two aluminous metasedimentary xenoliths from quartz-latitic volcanic rocks from Mt. Amiata and Mt. Cimino, central Italy. Physical and electron microprobe data for the grandidierites and petrological data for the grandidierite-bearing xenoliths are presented. The grandidierites formed by a reaction involving pre-existing aluminium rich minerals, possibly at temperatures of at least 800 °C and at low pressures. The grandidierite from Mt. Amiata replaces sillimanite. Several common characteristics can be demonstrated for magmatic and metamorphic grandidierite-bearing rocks. It is suggested that metamorphic rocks in which grandidierite occurs have often undergone partial melting.


2019 ◽  
pp. 137-154
Author(s):  
Steven R. McCutcheon ◽  
James A. Walker

The Bathurst Mining Camp of northern New Brunswick is approximately 3800 km2 in area, encompassed by a circle of radius 35 km. It is known worldwide for its volcanogenic massive sulphide deposits, especially for the Brunswick No. 12 Mine, which was in production from 1964 to 2013. The camp was born in October of 1952, with the discovery of the Brunswick No. 6 deposit, and this sparked a staking rush with more hectares claimed in the province than at any time since.   In 1952, little was known about the geology of the Bathurst Mining Camp or the depositional settings of its mineral deposits, because access was poor and the area was largely forest covered. We have learned a lot since that time. The camp was glaciated during the last ice age and various ice-flow directions are reflected on the physiographic map of the area. Despite abundant glacial deposits, we now know that the camp comprises several groups of Ordovician predominantly volcanic rocks, belonging to the Dunnage Zone, which overlie older sedimentary rocks belonging to the Gander Zone. The volcanic rocks formed during rifting of a submarine volcanic arc on the continental margin of Ganderia, ultimately leading to the formation of a Sea of Japan-style basin that is referred to as the Tetagouche-Exploits back-arc basin. The massive sulphide deposits are mostly associated with early-stage, felsic volcanic rocks and formed during the Middle Ordovician upon or near the sea floor by precipitation from metalliferous fluids escaping from submarine hot springs.   The history of mineral exploration in the Bathurst Mining Camp can be divided into six periods: a) pre-1952, b) 1952-1958, c) 1959-1973, d) 1974-1988, and e) 1989-2000, over which time 45 massive sulphide deposits were discovered. Prior to 1952, only one deposit was known, but the efforts of three men, Patrick (Paddy) W. Meahan, Dr. William J. Wright, and Dr. Graham S. MacKenzie, focused attention on the mineral potential of northern New Brunswick, which led to the discovery of the Brunswick No. 6 deposit in October 1952. In the 1950s, 29 deposits were discovered, largely resulting from the application of airborne surveys, followed by ground geophysical methods. From 1959 to 1973, six deposits were discovered, mostly satellite bodies to known deposits. From 1974 to 1988, five deposits were found, largely because of the application of new low-cost analytical and geophysical techniques. From 1989 to 2000, four more deposits were discovered; three were deep drilling targets but one was at surface. RÉSUMÉLe camp minier de Bathurst, dans le nord du Nouveau-Brunswick, s’étend sur environ 3 800 km2 à l’intérieur d’un cercle de 35 km de rayon. Il est connu dans le monde entier pour ses gisements de sulfures massifs volcanogènes, en particulier pour la mine Brunswick n° 12, exploitée de 1964 à 2013. Le camp est né en octobre 1952 avec la découverte du gisement Brunswick n° 6 et a suscité une ruée au jalonnement sans précédent avec le plus d’hectares revendiqués dans la province qu’à présent.   En 1952, on savait peu de choses sur la géologie du camp minier de Bathurst ou sur les conditions de déposition de ses gisements minéraux, car l’accès était très limité et la zone était en grande partie recouverte de forêt. Nous avons beaucoup appris depuis cette période. Le camp était recouvert de glace au cours de la dernière période glaciaire et diverses directions d’écoulements glaciaires sont révélées sur la carte physiographique de la région. Malgré des dépôts glaciaires abondants, nous savons maintenant que le camp comprend plusieurs groupes de roches ordoviciennes à prédominance volcanique, appartenant à la zone Dunnage, qui recouvrent de plus vieilles roches sédimentaires de la zone Gander. Les roches volcaniques se sont formées lors du rifting d’un arc volcanique sous-marin sur la marge continentale de Ganderia, ce qui a finalement abouti à la formation d’un bassin de type mer du Japon, appelé bassin d’arrière-arc de Tetagouche-Exploits. Les gisements de sulfures massifs sont principalement associés aux roches volcaniques felsiques de stade précoce et se sont formés au cours de l’Ordovicien moyen sur ou proche du plancher océanique par la précipitation de fluides métallifères s’échappant de sources chaudes sous-marines.   L’histoire de l’exploration minière dans le camp minier de Bathurst peut être divisée en six périodes: a) antérieure à 1952, b) 1952-1958, c) 1959-1973, d) 1974-1988 et e) 1989-2000, au cours desquelles 45 dépôts de sulfures massifs ont été découverts. Avant 1952, un seul dépôt était connu, mais les efforts de trois hommes, Patrick (Paddy) W. Meahan, William J. Wright et Graham S. MacKenzie, ont attiré l’attention sur le potentiel minier du nord du Nouveau-Brunswick, ce qui a conduit à la découverte du gisement Brunswick n° 6 au mois d’octobre 1952. Dans les années 50, 29 gisements ont été découverts, résultant en grande partie de l’utilisation de levés aéroportés, suivis de campagnes géophysiques terrestres. De 1959 à 1973, six gisements ont été découverts. Ce sont essentiellement des formations satellites de gisements connus. De 1974 à 1988, cinq gisements ont été découverts, principalement grâce à l’utilisation de nouvelles techniques analytiques et géophysiques peu coûteuses. De 1989 à 2000, quatre autres gisements ont été découverts. Trois étaient des cibles de forage profondes, mais l’un était à la surface.


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