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Lava Worlds: From Early Earth to Exoplanets Geochemistry Pub Date : 2021-01-22 Keng-Hsien Chao; Rebecca deGraffenried; Mackenzie Lach; William Nelson; Kelly Truax; Eric Gaidos
The magma ocean concept was first conceived to explain the geology of the Moon, but hemispherical or global oceans of silicate melt could be a widespread lava world” phase of rocky planet accretion, and could persist on planets on short-period orbits around other stars. The formation and crystallization of magma oceans could be a defining stage in the assembly of a core, origin of a crust, initiation
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BaFe[CO3]2, a new double carbonate: Synthesis, structural characterisation, and geostability implications for high and low PT Geochemistry Pub Date : 2021-01-16 Wen Liang; Christine Peters; Lin Li; Olaf Leupold; Heping Li; Michael E. Böttcher
For the first time, a new ordered double carbonate, BaFe(CO3)2, was synthesized by a solid-state reaction between BaCO3 and FeCO3 at high pressure-temperature conditions (PT; 3 GPa and 700 °C). This finding adds a new so-far unknown member to the group of norsethite-structured carbonates, which is often used as a geochemical analogue for dolomite. Thermogravimetric (TG) analysis and differential scanning
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On the origin of bleaching phenomena in red bed sediments of Triassic Buntsandstein deposits in Central Germany Geochemistry Pub Date : 2021-01-10 Michaela Aehnelt; Ulrike Hilse; Dieter Pudlo; Klaus Heide; Reinhard Gaupp
The Lower Triassic Buntsandstein in Central Germany comprises one of the major clastic, lithified hydrocarbon reservoirs, it is a major groundwater aquifer and it is considered as a potential underground gas storage lithology. Thus, sandstones of the Buntsandstein from Thuringia and NE Hesse were used to analyse their geochemical composition combined with mineralogical data in order to investigate
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Geochemistry of Gold-bearing Metamorphic Rocks of the Natitingou area, Atacora Structural Unit, Northwestern Bénin (West Africa): Implications for Au genesis Geochemistry Pub Date : 2021-01-06 Fatchéssin Bruno Adjo; Luc Adissin Glodji; Temidayo Anthony Bolarinwa; Prosper M. Nude; Bertrand Anagonou
The Natitingou area within the Atacora Structural Unit (ASU) of the Pan-African Dahomeyide orogenic belt, northwestern Bénin, is characterized by the monocyclic metasedimentary formations, amphibolites and orthogneisses which belong to the Internal zone of the belt. Representative samples of these different gold-bearing rocks have been analyzed geochemically to determine their petrogenesis, mode of
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1981–2020 winter ozone trends, Erzgebirge, Central Europe Geochemistry Pub Date : 2020-12-31 Hannah Gebhardt; Frank Zimmermann; Jörg Matschullat
Tropospheric ozone (O3) acts as greenhouse gas and air pollutant. Over the last 100 years, tropospheric O3 levels increased above background by factor 2.5 in the northern hemisphere and by factor 3–4 across Europe. The gas poses a potential risk to forest ecosystems in many mountain areas. There, O3 concentrations result from long-range transport and are influenced by removal processes (dry deposition
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Geochemical and thermodynamic modeling of the petrogenesis of A1-type granites and associated intermediate rocks: a case study from the central Fennoscandian Shield Geochemistry Pub Date : 2020-12-28 Kimmo Kärenlampi; Jussi S. Heinonen; Asko Kontinen; Eero Hanski; Hannu Huhma
The origin of ferroan A-type granites in anorogenic tectonic settings remains a long-standing petrological puzzle. The proposed models range from extreme fractional crystallization of mantle-derived magmas to partial melting of crustal rocks, or involve combination of both. In this study, we apply whole-rock chemical and Sm-Nd isotopic compositions and thermodynamically constrained modeling (Magma
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Weighting of BLEG data with drainage and catchment properties to enhance Au anomalies Geochemistry Pub Date : 2020-12-15 Behnam Sadeghi; Huseyin Yilmaz; Franco Pirajno
This research aims to take the effect of drainage sediment dilution into consideration by using catchment weighted-bulk leachable extractable gold (CW-BLEG) data in order to enhance and recognize Au anomalies. As a case study, an area in the Eskisehir region in Western Turkey was selected. In this area, gold-bearing crystalline quartz veins, of probable orogenic type, containing up to 20 g/t Au, occur
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Understanding mafic-felsic magma interactions in a subvolcanic magma chamber using rapakivi feldspar: A case study from the Bathani volcano-sedimentary sequence, eastern India Geochemistry Pub Date : 2020-12-15 Bibhuti Gogoi; Hiredya Chauhan; Ashima Saikia
The Ghansura Rhyolite Dome of the Bathani volcano-sedimentary sequence in eastern India originated from a subvolcanic felsic magma chamber that was intruded by volatile-rich basaltic magma during its evolution leading to the formation of a porphyritic andesite. The porphyritic andesite consists of rapakivi feldspars, which are characterized by phenocrysts of alkali feldspar mantled by plagioclase rims
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Mineralogy and Spectroscopy (Visible Near Infrared and Fourier Transform Infrared) of Mukundpura CM2: Implications for asteroidal aqueous alteration Geochemistry Pub Date : 2020-12-14 S. Baliyan; H. Moitra; S. Sarkar; D. Ray; D.K. Panda; A.D. Shukla; S. Bhattacharya; S. Gupta
We report the textures, mineralogy and mineral chemistry of the Mukundpura matrix component, a clast-bearing, brecciated, new CM2 carbonaceous chondrite. Like other CMs, Mukundpura is matrix-enriched and has experienced different degrees of aqueous alteration with evidences of fracturing and compaction of clasts due to the impact. A few relict chondrule clasts and CAIs (diopside and spinel) survived
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Petrogenesis of mafic microgranular enclaves (MMEs) in the Oligocene-Miocene granitoid plutons from northwest Anatolia, Turkey Geochemistry Pub Date : 2020-12-11 Şenel Özdamar; Haibo Zou; Mehmet Z. Billor; Willis E. Hames
Mafic microgranular enclaves (MMEs) in host granitoids can provide important constraints on the deep magmatic processes. The Oligocene-Miocene granitoid plutons of the NW Anatolia contain abundant MMEs. This paper presents new hornblende Ar-Ar ages and whole-rock chemical and Sr-Nd isotope data of the MMEs from these granitic rocks. Petrographically, the MMEs are finer-grained than their host granites
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Rb–Sr dating of sulfides and S–Pb isotopic study of the Bayanbaolege Ag polymetallic deposit, Inner Mongolia, NE China Geochemistry Pub Date : 2020-12-08 Xi Wang; Yunsheng Ren; Qun Yang; Dongsheng Zhao
The large-scale Bayanbaolege Ag polymetallic deposit is situated in the Tuquan–Linxi Fe-Sn-Cu-Pb-Zn-Ag metallogenic sub-belt in eastern slopes of the southern Great Xing’an Range, NE China. The sulfide-quartz vein-type orebodies in the deposit are hosted primarily in the Early Cretaceous granodiorite porphyry and Late Permian strata. Three primary paragenetic stages of veining have been identified:
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Ni isotope fractionation during coprecipitation of Fe(III)(oxyhydr)oxides in Si solutions Geochemistry Pub Date : 2020-11-23 Anna Neubeck; Christoffer Hemmingsson; Arjen Boosman; Olivier Rouxel; Madeleine Bohlin
The dramatic decline in aqueous Ni concentrations in the Archean oceans during the Great Oxygenation Event is evident in declining solid phase Ni concentrations in Banded Iron Formations (BIFs) at the time. Several experiments have been performed to identify the main removal mechanisms of Ni from seawater into BIFs, whereby adsorption of Ni onto ferrihydrites has shown to be an efficient process. Ni
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Pyroxenite xenoliths and clinopyroxene megacrysts from the Cenozoic Jbel Saghro Volcanic Field (Anti-Atlas, Morocco): Petrography, mineral chemistry and equilibration conditions Geochemistry Pub Date : 2020-11-12 Abdelghani Soukrati; Nasrrddine Youbi; Michel Grégoire; Julien Berger; Moulay Ahmed Boumehdi; Abderrahmane Ibhi; Khalid Rkha Chaham
A suite of mafic pyroxenite xenoliths and clinopyroxene megacrysts was brought to the surface by Cenozoic nephelinites of the Jbel Saghro Volcanic Field (Anti-Atlas, Morocco). The large population of samples was subdivided into five groups: (i) clinopyroxenites sensu stricto; (ii) olivine clinopyroxenites; (iii) mica-bearing clinopyroxenites; (iv) kaersutite-bearing clinopyroxenites; (v) clinopyroxene
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Spatial distribution, pollution characterization and health risk assessment of selected metals in groundwater of Lahore, Pakistan Geochemistry Pub Date : 2020-11-12 Yasir Karim Khan; Muhammad Toqeer; Munir H. Shah
Groundwater pollution is a major global environmental issue especially in the large cities and trace metals are considered as most important aquatic pollutants. The present study is based on the measurement and characterization of various physicochemical parameters (pH, EC, TDS, DO, alkalinity, hardness, and chloride), major cations (Ca, Mg, Na and K) and selected trace metals (Sr, Li, Fe, Zn, Cu,
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Petrology of granitoids from Indus Syntaxis, northern Pakistan: implications for Paleo-Proterozoic A-type magmatism in north-western Indian Plate Geochemistry Pub Date : 2020-11-11 Tanveer Ahmad; Mohammad Arif; Muhammad Qasim; Muhammad Sajid
The granites are exposed at Dubair and Shang respectively in the north and south of Besham, northern Pakistan. The two exposures are very similar in terms of field features, petrographic details, petrogenetically important geochemical parameters and, more importantly, crystallization temperatures and ages. All this strongly suggests that granites at the two locations are co-genetic and represent two
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Genesis of the Maanqiao gold deposit in the western Qinling orogen, central China: Constraints from fluid inclusions and in-situ sulfur isotopes Geochemistry Pub Date : 2020-11-04 Lele Ding; Laimin Zhu; Xiao Xiong; Guowei Zhang; Shenghao Li
The western Qinling orogen (WQO) is one of the most important prospective gold provinces in China. The Maanqiao gold deposit, located on the southern margin of the Shangdan suture, is a representative gold deposit in the WQO. The Maanqiao deposit is hosted by the metasedimentary rocks of the Upper Devonian Tongyusi Formation. The EW-trending brittle-ductile shear zone controls the orebodies; they occur
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Genesis of the Late Archean granitoids of the northern part of the Dharwar foreland (Dharwar Craton), south India - insights from field, crystal size distribution, thermobarometry, microgeochemical and bulk-rock geochemical studies Geochemistry Pub Date : 2020-10-18 Chandan K. Boraiaha; Annappa G. Ugarkar; Jayant K. Padhi; Rashmi Chandan; Mallappa V. Kallapur
An intrusive granitoid pluton into TTG-Dharwar Supergroup greenstone sequence is being reported for the first time from the Dharwar Foreland region. Based on field and petrographic characteristics, these granitoids are classified as - quartz-monzodiorites and granites. Occasional mafic bodies of dioritic- granodioritic composition with size ranging from small microgranular magmatic enclaves to bodies
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Geochemistry of Khor Um-Safi ophiolitic serpentinites, central Eastern Desert, Egypt: Implications for Neoproterozoic arc-basin system in the Arabian-Nubian Shield Geochemistry Pub Date : 2020-10-15 Shehata Ali; Theodoros Ntaflos; Mabrouk Sami
Serpentinites in the Eastern Desert of Egypt are the most distinctive lithological unit in the Arabian–Nubian Shield (ANS) ophiolite sequence which associated with major suture zones. Khor Um-Safi (KUS) serpentinites represent dismembered fragments of ophiolitic rocks located in the central Eastern Desert (CED) of Egypt. KUS serpentinites exhibit affinity to the typical metamorphic peridotites with
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Geochemical characterization of the Paleoproterozoic (ca. 1.98-1.97) Darguwan-Surajpura mafic sills within the Bijawar basin, North-Central India: genetic aspects and geodynamic implications Geochemistry Pub Date : 2020-10-15 Sangram K. Singh; Rajesh K. Srivastava; Suresh Kumar; Amiya K. Samal
The widespread records of mafic intrusives (both sills and dykes) are reported from the Proterozoic sedimentary basins of the Indian Shield. Amongst them, the Bijawar basin is also intruded by Paleoproterozoic (ca. 1.98-1.97 Ga) mafic sills. We provide first hand information on petrological and geochemical characteristics of these mafic sills together with a few NW-trending mafic dykes belong to the
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Zircon U-Pb ages, geochemistry, and Sr-Nd isotope ratios for Early Cretaceous magmatic rocks, southern Saqqez, northwestern Iran Geochemistry Pub Date : 2020-10-02 Somayeh Gholipour; Hossein Azizi; Fariborz Masoudi; Yoshihiro Asahara; Motohiro Tsuboi
Sanandaj-Sirjan Zone (SaSZ) is one of the most dynamic structural zones of Iran, which is divided into three main parts: Northern, Central and Southern. The northern SaSZ has been affected by deformation due to fault activities near the Zagros suture zone, and mylonitic structures have overprinted these rocks and was affected by three episodes of magma injection during the Permian-Carboniferous, Early
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COMPOSITION AND ORIGIN OF THE VOLATILE COMPONENTS RELEASED FROM THE PESYANOE AUBRITE BY STEPWISE CRUSHING AND HEATING Geochemistry Pub Date : 2020-10-02 C.A. Lorenz; A.I. Buikin; A.A. Shiryaev; O.V. Kuznetsova
Aubrites are achondritic meteorites (enstatite pyroxenites) that were formed in highly reduced magmatic environments on a differentiated parent body sharing a common oxygen isotope reservoir with enstatite chondrites (EC), Earth and Moon, and could be considered as a geochemical model of the early proto-Earth. Some pyroxenes of the Pesyanoe aubrite have high abundance of gaseous inclusions, captured
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Geochemical appraisal of fluoride contaminated groundwater in the vicinity of a coal mining region: Spatial variability and health risk assessment Geochemistry Pub Date : 2020-09-29 Krishna Yadav; Mohd. Raphi; Sheeja Jagadevan
The present study focuses on the geochemical characteristics and quality of potable groundwater in mining area, particularly with reference to fluoride (F−). Spatial variability in physicochemical parameters of groundwater samples (32) collected from Katras block coal mine area was analysed. Parameters such as total hardness, total alkalinity, calcium (Ca2+), sodium (Na+), bicarbonate ( HCO3- ) and
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Geochronological constraints on uranium mineralization within the Hüttenberg siderite deposit (Eastern Alps, Austria) Geochemistry Pub Date : 2020-09-24 Michael Waitzinger; Dominik Sorger; Werner Hermann Paar; Fritz Finger
A small-scale hydrothermal uranium mineralization hosted within the siderite deposit at Hüttenberg (Eastern Alps, Austria) was re-investigated using modern scanning electron microscope (SEM) and microprobe (EMPA) methods. The uranium mineralization comprises brannerite, coffinite and uraninite, and is spatially associated with Fe-, Ni- and Co-arsenides (loellingite, rammelsbergite, safflorite), bismuth
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Ages of lunar impact breccias: limits for timing of the Imbrium impact Geochemistry Pub Date : 2020-09-24 Alexander A. Nemchin; Tao Long; Bradley L. Jolliff; Yusheng Wan; Joshua F. Snape; Ryan Zeigler; Marion L. Grange; Dunyi Liu; Martin J. Whitehouse; Nicholas E. Timms; Fred Jourdan
Since the Apollo 14 mission delivered samples of the Fra Mauro formation, interpreted as ejecta of the Imbrium impact, defining the age of this impact has emerged as one of the critical tasks required for the complete understanding of the asteroid bombardment history of the Moon and, by extension, the inner Solar System. Significant effort dedicated to this task has resulted in a substantial set of
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Textural re-equilibration, hydrothermal alteration and element redistribution in Fe-Ti oxide pods, Singhbhum Shear Zone, eastern India Geochemistry Pub Date : 2020-09-21 Subhadip Adak; Dipak C. Pal; Dewashish Upadhyay; Rajdeep Mondal
This study describes textures and mineral chemistry of magnetite-ilmenite-bearing pods/pockets in mineralogically diverse feldspathic schist near Pathargora in the Singhbhum shear zone, eastern India. The textural and geochemical characteristics of the magnetite-ilmenite assemblage are the results of a protracted geological history involving magmatic crystallization and oxidation-exsolution of titanomagnetite
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Petrogenesis and tectonic significance of the Early Devonian lamprophyres and diorites in the Alxa Block, NW China Geochemistry Pub Date : 2020-09-19 Renyu Zeng; Jianqing Lai; Xiancheng Mao; Wenzhou Xiao; Jie Yan; Chenguang Zhang; Jianxiong Hu
The North Qilian orogenic belt (NQOB) has been defined as a subduction-collision zone between the Alxa Block and the Qilian Block during the Early Paleozoic. To constrain the post-collisional tectonic evolution of the NQOB, analyses of zircon U-Pb-Hf isotopes, whole-rock major, trace element and Sr-Nd-Pb isotope compositions of the newly discovered Early Devonian lamprophyres and diorites dikes from
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Late Magmatic – Hydrothermal Tourmaline Occurrences within Leucogranites in NW Anatolia (Turkey): Mineral Chemistry and Genetic Implications Geochemistry Pub Date : 2020-09-18 Namık Aysal; Sinan Öngen; Nurullah Hanilçi; Cem Kasapçı; Davut Laçin; Mehtap Şafak Boroğlu; Mehmet Yesiltaş; İsak Yılmaz; Direnç Azaz
Numerous Oligo-Miocene plutonic and associated aplite-pegmatite rocks occur in the Western Anatolian Magmatic Complex. However, only the plutons of Namazgah, Karadağ, Soğucak and Karadoru, in the Biga Peninsula, host three different types of tourmaline: disseminated, nodular, and vein-type. These all fall into the alkali subgroup and schorl-oxy-schorl-dravite-oxy-dravite solid solution series. This
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Whole-rock chemistry of the Gameleira I uranium deposit, Lagoa Real, Brazil Geochemistry Pub Date : 2020-09-13 Camila Marques dos Santos; Alexandre Raphael Cabral; Francisco Javier Rios
The Lagoa Real uranium (U) province, referred to as Lagoa Real, is located in the state of Bahia, north-eastern Brazil. Lagoa Real has ∼112,000 metric tonnes of U3O8 and an average grade of 2700 ppm, being one of the largest U deposits in the world and the largest in Brazil. Despite its economic and strategic importance, there are gaps in the geological knowledge of the Lagoa Real U deposits. One of
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Hydrogeochemical contrast between two study areas of Bengal delta, India: A comparative insight to understand arsenic mobilization process in shallow aquifers Geochemistry Pub Date : 2020-09-12 Ayan Das; Aparna Banerjee; Aniruddha Roy
A comparative hydrogeochemical study evaluated arsenic release mechanism and differences in contamination levels in the shallow groundwater of two areas within the deltaic environment of West Bengal (i.e. Karimpur and Tehatta blocks of Nadia district) in India. Groundwaters from both the areas are Ca-Na(K)-Cl-HCO3 type with highly reducing character (-110.16 ± 16.85 to -60.77 ± 16.93 mV). Low correlations
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Combined zircon U-Pb dating and chemical Th–U–total Pb chronology of monazite and thorite, Abu Diab A-type granite, Central Eastern Desert of Egypt: Constraints on the timing and magmatic-hydrothermal evolution of rare metal granitic magmatism in the Arabian Nubian Shield Geochemistry Pub Date : 2020-07-15 Nasser M. Mahdy; Theodoros Ntaflos; Victoria Pease; Mabrouk Sami; Marek Slobodník; Ahmed A. Abu Steet; Khaled M. Abdelfadil; Douaa Fathy
We present the first chemical age determination of monazite from a geochemically-specialized rare metal granite of the Central Eastern Desert (CED), Egypt. The Abu Diab composite A-type granite of the CED divides into three co-magmatic phases: two mica granite (TG), garnet-bearing muscovite granite (GMG), and muscovite granite (MG). The GMG granitic phase is a typical example of a rare metal, volatile-rich
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Rare earth elements geochemistry of groundwater from Shanmuganadhi, Tamilnadu, India: Chemical weathering implications using geochemical mass-balance calculations Geochemistry Pub Date : 2020-07-03 F. Vinnarasi; K. Srinivasamoorthy; K. Saravanan; S. Gopinath; R. Prakash; G. Ponnumani; C. Babu
Groundwater samples were collected from Shanmughanadhi in Dindigul district of Tamilnadu, India, to determine the concentration and fractionation of REEs during chemical weathering. Groundwater samples collected from aquifers hosted in weathered and fractured crystalline formations were analyzed by ICP-MS for Rare earth elements (REEs) after filtering by 0.45 μm membrane filters. ΣREEs in Charnockite
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Provenance of detrital rutiles from the Jurassic sandstones in the Central Sakarya Zone, NW Turkey: U-Pb ages and trace element geochemistry Geochemistry Pub Date : 2020-06-12 Fırat Şengün; Thomas Zack; István Dunkl
This provenance study focuses on detrital rutile grains from Jurassic sandstones of the Bayırköy Formation in the central Sakarya Zone. Cr and Nb concentrations of detrital rutile grains in the Jurassic sandstones vary from 18 to 6855 μg/g and 70–13440 μg/g, respectively. Source area discrimination based on the Cr-Nb concentrations shows that 79 % of the detrital rutile grains originated from metapelitic
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Conditions for the crystallization of fluorite in the Mushgai-Khudag complex (Southern Mongolia): Evidence from trace element geochemistry and fluid inclusions Geochemistry Pub Date : 2020-06-12 Anna A. Redina; Anna M. Nikolenko; Anna G. Doroshkevich; Ilya R. Prokopyev; Cora Wohlgemuth-Ueberwasser; Nikolay V. Vladykin
The Mushgai-Khudag complex is part of the Late Mesozoic Central Asian carbonatite province. Fluorite mineralization is manifested throughout the province, including the Mushgai-Khudag complex. We have investigated the geochemical features and fluid inclusions of fluorites from different types of fluorite-bearing rocks. Fluorite from quartz-fluorite rocks has rare earth element (REE) concentrations
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Hydrogeochemical investigation of an epithermal mineralization bearing basin using multivariate statistical techniques and isotopic evidence of groundwater: Kestanelik Sub-Basin, Lapseki, Turkey Geochemistry Pub Date : 2020-06-09 Erkan Dişli; Nilay Gülyüz
This study investigates hydrogeochemical processes controlling the groundwater quality using 64 groundwater samples in the epithermal mineralization bearing Kestanelik Sub Basin, NW Turkey. The groundwater dominantly exhibits a mixed-ion hydrochemical facies characterized by Ca-Mg-HCO3, Mg-Ca-HCO3, Ca-Mg--HCO3-SO4 and Ca-Mg-Na-HCO3 reflecting weakly mineralized waters circulating within calcareous
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Geochemistry of Bashibos-Bajrambos metasedimentary unit, Serbo-Macedonian massif, North Macedonia: Implications for age, provenance and tectonic setting Geochemistry Pub Date : 2020-06-04 Aleš Šoster; Janez Zavašnik; Paul O'Sullivan; Uroš Herlec; Barbara Potočnik Krajnc; Ladislav Palinkaš; Nina Zupančič; Matej Dolenec
Metasediments of the Paleozoic Bashibos-Bajrambos unit, comprising the western perimeter of the Serbo-Macedonian Massif in SE Republic of North Macedonia, were investigated by employing whole-rock geochemistry and detrital zircon geochronology to put constraints of age, provenance and depositional tectonic setting. The metasedimentary unit consists of polymetamorphic and highly altered pelitic mica-schists
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Petrology and geochemistry of ignimbrites and associated enclaves from Mount Bambouto, West-Cameroon, Cameroon Volcanic Line Geochemistry Pub Date : 2020-05-30 Merlin Gountié Dedzo; Djamilatou Diddi Hamadjoda; Eric Martial Fozing; Boris Chako Tchamabé; Ana Teresa Mendoza-Rosas; Asobo Nkengmatia Elvis Asaah; Ghislain Zangmo Tefogoum; Pierre Kamgang; Takeshi Ohba
Geochemical and mineralogical analyses data are presented for ignimbritic deposits from the Bambouto volcano. These deposits are characterized by their welded and non-welded massive lapilli tuff and massive lithic breccias facies. The ignimbrites generally display vitroclastic and/or eutaxitic texture characterized by whole or broken minerals, subangular fragments of trachytes, rhyolites, ignimbrites
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Late Cretaceous-Cenozoic exhumation of Northwestern Guangxi (China) and tectonic implications: Evidence from apatite fission track dating Geochemistry Pub Date : 2020-05-24 Jianbiao Wu; Qiaohui Pi; Bin Zhu; Yunhu Hu; Guo Li; Chaowen Wei
The study of the Late Cretaceous-Cenozoic uplift and tectonic evolution of the Northwestern Guangxi area in the Youjiang Basin is relevant for understanding the origin and preservation of hydrothermal deposits with ore-hosting potential. Apatite fission-track dating and time-temperature thermal history modelling were performed using six rock samples from the study area. The ages were found to range
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Multiple sulfur sources for the volcanic hosted massive sulfides in Betul Belt, Central India: Evidence from the sulfide ore chemistry and sulfur isotope geochemistry Geochemistry Pub Date : 2020-05-12 Mohammad Atif Raza; Mohamed Shareef; Venkata Sri Surya Apla Naidu Badireddi; Hemraj Suryavanshi; Srinivasa Rao Baswani; Muduru Lachhana Dora; Tushar Meshram; Parwez Akhter; Raghuram; Shraddha Kumari; Biswabara Panda; Sushanta Kumar Saha; Lalit Mohan Singh Maura; Subhra Suchi Sarkar; Manish M John; Smitha Ramachandran Sarala Bai
This work provides an overview of the geological, petrological, and geochemical data available on the three volcanic-hosted massive sulfides (VHMS) deposits (Ghisi, Biskhan, and Jangaldehri) in Betul Belt, Central Indian Tectonic Zone. Sulfur isotope geochemistry was used for the first time from the Betul Belt to constrain the source of sulfur for a better understanding of the ore genesis process.
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Seasonal changes in groundwater composition in an industrial center of south India and quality evaluation for consumption and health risk using geospatial methods Geochemistry Pub Date : 2020-05-12 Venkatesan G.; Subramani T.; Sathya U.; Priyadarsi D. Roy
Effluents from leather tanneries and other small-scale industries have caused groundwater contamination in one of the biggest industrial centers (i.e. Vellore) of south India. This study evaluated quality of 70 different open and tube wells for consumption and health risks by collecting groundwater samples in four different seasons between 2017-2018. We compared physicochemical parameters of the groundwater
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Isotopic clues tracking the open-system evolution of the Ponte Nova mafic-ultramafic alkaline massif, SE Brazil: The contribution of Pb isotopes Geochemistry Pub Date : 2020-05-12 Rogério Guitarrari Azzone; Luanna Chmyz; Vincenza Guarino; Adriana Alves; Celso de Barros Gomes; Excelso Ruberti
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Hydrogeochemical and isotopic study for evaluation of seawater intrusion into shallow coastal aquifers of Udupi District, Karnataka, India Geochemistry Pub Date : 2020-05-03 Ratnakar Dhakate; G. Venkata Ratnalu; S. Sankaran
Groundwater is the major source of drinking in coastal areas and the gradual decline in its quality is a major concern. The present study was aimed to evaluate the groundwater quality and its deterioration in coastal aquifer in the Udupi district of Karnataka state (southwest India) by studying the hydrogeochemical characteristics and salinization processes. We collected 49 groundwater samples from
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GeoBalance: An Excel VBA program for mass balance calculation in geosciences Geochemistry Pub Date : 2020-05-01 Xiaoyan Li; Chao Zhang; Renat R. Almeev; Francois Holtz
Mass balance calculation is a fundamental approach in geosciences. In petrology and geochemistry, it is widely used for quantitative characterization of phase transition and mass transfer. In a routine petrological practice, this method is commonly used to calculate proportions of the minerals formed from initial or parental bulk composition, or to quantify the reaction coefficients for minerals involved
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Temporal changes in geochemical-isotopic systematics of the late Pleistocene Akkaya travertines (Turkey) – Implications for fluid flow circulation and seismicity Geochemistry Pub Date : 2020-04-30 Gokhan Yıldırım; Halim Mutlu; Volkan Karabacak; I. Tonguç Uysal; Kadir Dirik; Abidin Temel; Galip Yüce; Jian-xin Zhao
We investigate the temporal variations in stable carbon and oxygen and radiogenic Sr isotope as well as rare earth element contents of Akkaya travertine deposits in the Eskipazar region, northwest Turkey. U-Th age data indicate that studied travertines in the periphery of the 1944-earthquake rupture of the North Anatolian Fault Zone formed in a time span of 93 to 1.8 ka BP. The younger group is represented
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Hydrogeochemical evolution of Hexavalent chromium in the Sukinda Ultramafic Complex in eastern part of India Geochemistry Pub Date : 2020-04-28 Sk. Md. Equeenuddin; Binaya Kumar Pattnaik
The ultramafic complex in Sukinda hosts the largest chromite deposit of India and weathering of these ultramafic rocks is recognised as the source of Cr(VI) in different water resources of this region. This paper presents the geochemical characteristics of mine water, surface water and groundwater in order to understand the processes governing the water quality. Water is mildly oxidizing (Eh: 12.3-245
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The Renazzo-like carbonaceous chondrites as resources to understand the origin, evolution, and exploration of the solar system Geochemistry Pub Date : 2020-04-27 N.M. Abreu; J.C. Aponte; E.A. Cloutis; A.N. Nguyen
We present here a review of the characteristics of CR carbonaceous chondrite meteorites. Over the past three decades, our knowledge and understanding of the scientific value of the CR chondrites have increased dramatically, as more samples from cold and hot deserts have become available for analysis. Based on a variety of compositional, mineralogical, isotopic, and spectroscopic studies, we have come
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Adakitic signal linked to Gondwanan porphyry type deposits from the Andean Frontal Cordillera of Argentina Geochemistry Pub Date : 2020-04-25 María Gabriela Torres; Nora Rubinstein; Gregory Poole; Steffen Hagemann
The Yalguaraz Cu - (Mo) porphyry deposit, genetically linked to the early Permian magmatism (279.9 ± 3.2 Ma), is located at the eastern margin of the Andean Frontal Cordillera of Argentina, 15 km north of the Permian San Jorge Cu porphyry deposit. The geochemistry of this Gondwanan metal-bearing magmatism reveals an arc affinity and an adakite-like signature. The petrogenetic analysis of these rocks
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A light, chondritic xenolith in the Murchison (CM) chondrite – Formation by fluid-assisted percolation during metasomatism? Geochemistry Pub Date : 2019-06-24 Imene Kerraouch; Samuel Ebert; Markus Patzek; Addi Bischoff; Michael E. Zolensky; Andreas Pack; Philippe Schmitt-Kopplin; Djelloul Belhai; Abderrahmane Bendaoud; Loan Le
The main mineralogical characteristics of a large light-colored clast within the Murchison CM breccia are discussed in detail including data on the mineralogy, bulk chemistry, organics, and oxygen isotopes. Petrographic study shows that the white clast consists of two areas with different granoblastic textures: (1) a coarse-grained (average grain size: ∼200 μm) and (2) a fine-grained lithology (average
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Mineralogy, petrography, and oxygen isotopic compositions of ultrarefractory inclusions from carbonaceous chondrites Geochemistry Pub Date : 2019-08-15 A.N. Krot; C. Ma; K. Nagashima; A.M. Davis; J.R. Beckett; S.B. Simon; M. Komatsu; T.J. Fagan; F. Brenker; M.A. Ivanova; A. Bischoff
We report on the mineralogy, petrography, and in situ oxygen isotopic composition of twenty-five ultrarefractory calcium-aluminum-rich inclusions (UR CAIs) in CM2, CR2, CH3.0, CV3.1–3.6, CO3.0–3.6, MAC 88107 (CO3.1-like), and Acfer 094 (C3.0 ungrouped) carbonaceous chondrites. The UR CAIs studied are typically small, < 100 μm in size, and contain, sometimes dominated by, Zr-, Sc-, and Y-rich minerals
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Formation of disk- and bowl-shaped igneous Ca,Al-rich inclusions: Constraints from their morphology, textures, mineralogy and modelling Geochemistry Pub Date : 2019-08-19 C. Lorenz; M. Ivanova; A. Krot; V. Shuvalov
Calcium-aluminum-rich inclusions (CAIs) are the oldest Solar System solids dated that formed by evaporation, condensation, aggregation and, sometimes, melting processes near the protoSun, and were subsequently dispersed throughout the protoplanetary disk by still poorly-understood mechanism(s). Here we report on the discovery of disk- and bowl-shaped centimeter-sized igneous CAIs in CV (Vigarano type)
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Heating duration of igneous rim formation on a chondrule in the Northwest Africa 3118 CV3oxA carbonaceous chondrite inferred from micro-scale migration of the oxygen isotopes Geochemistry Pub Date : 2019-08-10 Nozomi Matsuda; Naoya Sakamoto; Shogo Tachibana; Hisayoshi Yurimoto
Due to their common occurrence in various types of chondrites, igneous rims formed on pre-existing chondrules throughout chondrule-forming regions of the solar nebula. Although the peak temperatures are thought to reach similar values to those achieved during chondrule formation events, the heating duration in chondrule rim formation has not been well defined. We determined the two-dimensional chemical
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Differentiation and magmatic history of Vesta: Constraints from HED meteorites and Dawn spacecraft data Geochemistry Pub Date : 2019-09-14 Harry Y. McSween; Carol A. Raymond; Edward M. Stolper; David W. Mittlefehldt; Michael B. Baker; Nicole G. Lunning; Andrew W. Beck; Timothy M. Hahn
Quantifying the amounts of various igneous lithologies in Vesta’s crust allows the estimation of petrologic ratios that describe the asteroid’s global differentiation and subsequent magmatic history. The eucrite:diogenite (Euc:Diog) ratio measures the relative proportions of mafic and ultramafic components. The intrusive:extrusive (I:E) ratio assesses the effectiveness of magma ascent and eruption
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The Renchen L5-6 chondrite breccia – The first confirmed meteorite fall from Baden-Württemberg (Germany) Geochemistry Pub Date : 2019-07-27 Addi Bischoff; Jean-Alix Barrat; Jasper Berndt; Jiri Borovicka; Christoph Burkhardt; Henner Busemann; Janina Hakenmüller; Dieter Heinlein; Jasmine Hertzog; Jozef Kaiser; Colin Maden; Matthias M.M. Meier; Précillia Morino; Andreas Pack; Markus Patzek; Maximilian P. Reitze; Miriam Rüfenacht; Philippe Schmitt-Kopplin; Tomas Zikmund
On July 10, 2018 at 21:29 UT extended areas of South-Western Germany were illuminated by a very bright bolide. This fireball was recorded by instruments of the European Fireball Network (EN). The records enabled complex and precise description of this event including the prediction of the impact area. So far six meteorites totaling about 1.23 kg have been found in the predicted location for a given
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Formation and destruction of magnetite in CO3 chondrites and other chondrite groups Geochemistry Pub Date : 2019-07-31 Alan E. Rubin; Ye Li
Primitive CO3.00–3.1 chondrites contain ∼2-8 vol.% magnetite, minor troilite and accessory carbide and chromite; some CO3.1 chondrites have fayalite-rich veins, chondrule rims and euhedral matrix grains. All CO3.00–3.1 chondrites contain little metallic Fe-Ni (0.4–1.2 vol.%). CO3.2–3.7 chondrites contain 1–5 vol.% metallic Fe-Ni, minor troilite, accessory chromite and 0-0.6 vol.% magnetite. Magnetite
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Mineralogy, petrography, and oxygen and aluminum-magnesium isotope systematics of grossite-bearing refractory inclusions Geochemistry Pub Date : 2019-08-15 Alexander N. Krot; Kazuhide Nagashima; Steven B. Simon; Chi Ma; Harold C. Connolly; Gary R. Huss; Andrew M. Davis; Martin Bizzarro
Grossite (CaAl4O7) is one of the one of the first minerals predicted to condense from a gas of solar composition, and therefore could have recorded isotopic compositions of reservoirs during the earliest stages of the Solar System evolution. Grossite-bearing Ca,Al-rich inclusions (CAIs) are a relatively rare type of refractory inclusions in most carbonaceous chondrite groups, except CHs, where they
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Modal abundances of coarse-grained (>5 μm) components within CI-chondrites and their individual clasts – Mixing of various lithologies on the CI parent body(ies) Geochemistry Pub Date : 2019-08-20 Julian Alfing; Markus Patzek; Addi Bischoff
For the bulk rocks of CI chondrites, various values are given for the modal abundance of matrix (95–100 vol%) and the accompanying mineral constituents. Here, we have determined the modal abundance of phases >5 μm in the CI chondrites Orgueil, Ivuna, Alais, and Tonk. Considering this cut-off grain-size to distinguish between matrix and coarse-grained constituents, then, we find the modal abundance
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The Yamato-type (CY) carbonaceous chondrite group: Analogues for the surface of asteroid Ryugu? Geochemistry Pub Date : 2019-08-20 A.J. King; H.C. Bates; D. Krietsch; H. Busemann; P.L. Clay; P.F. Schofield; S.S. Russell
We report new mineralogical, petrographic and noble gas analyses of the carbonaceous chondrite meteorites Y-82162 (C1/2ung), Y-980115 (CI1), Y-86029 (CI1), Y-86720 (C2ung), Y-86789 (C2ung), and B-7904 (C2ung). Combining our results with literature data we show that these meteorites experienced varying degrees of aqueous alteration followed by short-lived thermal metamorphism at temperatures of >500 °C
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Grove Mountains (GRV) 020043: Insights into acapulcoite-lodranite genesis from the most primitive member Geochemistry Pub Date : 2019-09-07 Timothy J. McCoy; Catherine M. Corrigan; Tamara L. Dickinson; Gretchen K. Benedix; Devin L. Schrader; Jemma Davidson
Although acapulcoites and lodranites played a key role in understanding partial differentiation of asteroids, the lack of samples of the chondritic precursor limits our understanding of the processes that formed these meteorites. Grove Mountains (GRV) 020043 is a type 4 chondrite, with abundant, well-delineated, pyroxene-rich chondrules with an average diameter of 690 μm, microcrystalline mesostasis
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Mineralogy, petrology, and oxygen isotopic composition of Northwest Africa 12379, metal-rich chondrite with affinity to ordinary chondrites Geochemistry Pub Date : 2019-09-10 Christian A. Jansen; Frank E. Brenker; Jutta Zipfel; Andreas Pack; Luc Labenne; Kazuhide Nagashima; Alexander N. Krot; Martin Bizzarro; Martin Schiller
Northwest Africa (NWA) 12379 is a new metal-rich chondrite with unique characteristics distinguishing it from all previously described meteorites. It contains high Fe,Ni-metal content (∼ 70 vol.%) and completely lacks interchondrule matrix; these characteristics are typical only for metal-rich carbonaceous (CH and CB) and G chondrites. However, chondrule sizes (60 to 1200 μm; mean = 370 μm), their
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Roaldite in the iron-meteorite São Julião de Moreira Geochemistry Pub Date : 2019-10-18 Gert Nolze; Klaus Heide
Roaldite – Fe4N – has been identified in the São Julião de Moreira iron meteorite using electron backscatter diffraction (EBSD) and simultaneously acquired energy-dispersive x-ray spectroscopy (EDS). Mean-periodic-number images derived from raw EBSD patterns confirm this phase by an even higher spatial resolution compared to EDS. Roaldite appears in the form of systematically and repetitively aligned
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Heating experiments relevant to the depletion of Na, K and Mn in the Earth and other planetary bodies Geochemistry Pub Date : 2019-09-18 M. Gellissen; A. Holzheid; Ph. Kegler; H. Palme
We have studied the evaporation of Na, K and Mn from Al-Na-K- and Mn-rich silicates at various conditions. Total alkali oxide contents ranged from 5 to 20%. The evaporation rate of Na increases with temperature and decreasing oxygen fugacity and decreases with duration of heating. The loss of K is in all cases less pronounced than for Na. Heating in an evacuated vacuum furnace is more effective in
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