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Journal articles on the topic 'Lithophile trace elements'

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Published: 4 June 2021
Last updated: 1 February 2022

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1

Barrat, J. A., B. Zanda, A. Jambon, and C. Bollinger. "The lithophile trace elements in enstatite chondrites." Geochimica et Cosmochimica Acta 128 (March 2014): 71–94. http://dx.doi.org/10.1016/j.gca.2013.11.042.

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2

Wood, Bernard J., and Ekaterina S. Kiseeva. "Trace element partitioning into sulfide: How lithophile elements become chalcophile and vice versa." American Mineralogist 100, no. 11-12 (November 2015): 2371–79. http://dx.doi.org/10.2138/am-2015-5358ccbyncnd.

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3

Ionov, Dmitri A., William L. Griffin, and Suzanne Y. O'Reilly. "Volatile-bearing minerals and lithophile trace elements in the upper mantle." Chemical Geology 141, no. 3-4 (September 1997): 153–84. http://dx.doi.org/10.1016/s0009-2541(97)00061-2.

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4

Porcelli, D. R., R. K. O'Nions, S. J. G. Galer, A. S. Cohen, and D. P. Mattey. "Isotopic relationships of volatile and lithophile trace elements in continental ultramafic xenoliths." Contributions to Mineralogy and Petrology 110, no. 4 (May 1992): 528–38. http://dx.doi.org/10.1007/bf00344086.

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5

Barrat, Jean-Alix, Albert Jambon, Akira Yamaguchi, Addi Bischoff, Marie-Laure Rouget, and Céline Liorzou. "Partial melting of a C-rich asteroid: Lithophile trace elements in ureilites." Geochimica et Cosmochimica Acta 194 (December 2016): 163–78. http://dx.doi.org/10.1016/j.gca.2016.08.042.

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6

Good, David J., and Peter C. Lightfoot. "Significance of the metasomatized lithospheric mantle in the formation of early basalts and Cu – platinum group element sulfide mineralization in the Coldwell Complex, Midcontinent Rift, Canada." Canadian Journal of Earth Sciences 56, no. 7 (July 2019): 693–714. http://dx.doi.org/10.1139/cjes-2018-0042.

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A diverse suite of tholeiitic to alkaline basalt and gabbroic intrusions located in the Coldwell Complex on the northern margin of the Midcontinent Rift exhibit unusual trace element signatures that show enriched large ion lithophile elements and light rare earth elements with negative Nb and Zr anomalies. These features are not typical of magmas derived by partial melting within or above a rising mantle plume, as might be expected in an early Midcontinent Rift magmatic event. In this paper, we provide a detailed geochemical study of a 500 m thick sequence of metabasalt that represents the earliest stage of magmatism in the Coldwell Complex. We show that contamination or crystallization processes or subsequent metasomatism cannot explain the trace element variations. Instead, we propose partial melting in a metasomatized Subcontinental Lithospheric Mantle source to explain the decoupled behavior of large ion lithophile elements from light rare earth elements and heavy rare earth elements and rare earth elements from high field strength elements and the enriched Nd isotope signature of metabasalt. Similar features occur in unit 5b of the Mamainse Point Volcanic Group located at the northern margin of the Rift. An objective of this paper is to relate Two Duck Lake gabbro, host rock for low-sulfur, high precious metal sulfide mineralization at the Marathon deposit, to the metabasalt sequence. The excellent match of trace element abundances in Two Duck Lake gabbro to metabasalt unit 3 confirms an early Coldwell Complex age for metabasalt and a Subcontinental Lithospheric Mantle source for Cu – platinum group element mineralized gabbros.
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7

Javed, Muhammad Babar, Iain Grant-Weaver, and William Shotyk. "An optimized HNO3 and HBF4 digestion method for multielemental soil and sediment analysis using inductively coupled plasma quadrupole mass spectrometry." Canadian Journal of Soil Science 100, no. 4 (December 1, 2020): 393–407. http://dx.doi.org/10.1139/cjss-2020-0001.

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A robust and reliable analytical procedure for the determination of trace (mg∙kg−1) and ultra-trace elements (μg∙kg−1) in soil and sediments by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) was optimized. Aliquots of ∼200 mg of two certified reference materials (IAEA Soil-7, soil and IAEA SL-1, lake sediments) were digested in nitric acid (HNO3) purified twice by sub-boiling distillation using a microwave-heated high-pressure autoclave. Incremental addition of tetrafluoroboric acid (HBF4, 0.1–2 mL) to HNO3 was evaluated for yield. The selection of appropriate proportions of digestion acids was crucial to obtain accurate results. Digested samples were analyzed for a range of trace elements including those that are potentially toxic (Ag, Cd, Pb, Sb, and Tl), plant micronutrients (Cu, Fe, Mn, and Zn), those enriched in bitumen (Mo, Ni, and V), and lithophile elements (Al, Ba, Co, Cr, Rb, Sr, Th, Ti, Y, and Zr). Nitric acid alone proved to be sufficient to completely liberate Cd, Co, Cr, Fe, Mn, Ni, Pb, V, and Zn in both soil and sediments (87%–120% recovery). For almost all the other elements, addition of HBF4 was needed for improved recovery. A combination of 3 mL of HNO3 and 1.5 mL of HBF4 was optimal to fully liberate an extended list of elements including Ba, Sb, and Sr from both the reference materials. Conservative lithophile elements (Th, Ti, Y, and Zr) could not be completely recovered with the proposed method, requiring hydrofluoric acid for complete dissolution of recalcitrant minerals.
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8

Duran, Charley J., Sarah-Jane Barnes, Eduardo T. Mansur, Sarah A. S. Dare, L. Paul Bédard, and Sergey F. Sluzhenikin. "Magnetite Chemistry by LA-ICP-MS Records Sulfide Fractional Crystallization in Massive Nickel-Copper-Platinum Group Element Ores from the Norilsk-Talnakh Mining District (Siberia, Russia): Implications for Trace Element Partitioning into Magnetite." Economic Geology 115, no. 6 (September 1, 2020): 1245–66. http://dx.doi.org/10.5382/econgeo.4742.

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Abstract Mineralogical and chemical zonations observed in massive sulfide ores from Ni-Cu-platinum group element (PGE) deposits are commonly ascribed to the fractional crystallization of monosulfide solid solution (MSS) and intermediate solid solution (ISS) from sulfide liquid. Recent studies of classic examples of zoned orebodies at Sudbury and Voisey’s Bay (Canada) demonstrated that the chemistry of magnetite crystallized from sulfide liquid was varying in response to sulfide fractional crystallization. Other classic examples of zoned Ni-Cu-PGE sulfide deposits occur in the Norilsk-Talnakh mining district (Russia), yet magnetite in these orebodies has received little attention. In this contribution, we document the chemistry of magnetite in samples from Norilsk-Talnakh, spanning the classic range of sulfide composition, from Cu poor (MSS) to Cu rich (ISS). Based on textural features and mineral associations, four types of magnetite with distinct chemical composition are identified: (1) MSS magnetite, (2) ISS magnetite, (3) reactional magnetite (at the sulfide-silicate interface), and (4) hydrothermal magnetite (resulting from sulfide-fluid interaction). Compositional variability in lithophile and chalcophile elements records sulfide fractional crystallization across MSS and ISS magnetites and sulfide interaction with silicate minerals (reactional magnetite) and fluids (hydrothermal magnetite). Estimated partition coefficients for magnetite in sulfide systems are unlike those in silicate systems. In sulfide systems, all lithophile elements are compatible and chalcophile elements tend to be incompatible with magnetite, but in silicate systems some lithophile elements are incompatible and chalcophile elements are compatible with magnetite. Finally, comparison with magnetite data from other Ni-Cu-PGE sulfide deposits pinpoints that the nature of parental silicate magma, degree of sulfide evolution, cocrystallizing phases, and alteration conditions influence magnetite composition.
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9

Smith, Alan D. "Geochemistry and tectonic setting of volcanics from the Anyox mining camp, British Columbia." Canadian Journal of Earth Sciences 30, no. 1 (January 1, 1993): 48–59. http://dx.doi.org/10.1139/e93-005.

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Volcanogenic massive sulphide deposits at Anyox in the Tracy Arm terrane of the Canadian Cordillera are associated with a sequence of tholeiitic basalts with minor intercalated basaltic andesite tuffs and siliceous sediments. Sm–Nd and Pb–Pb systematics indicate an Early to Middle Jurassic age. The tholeiites are characterized by normal mid-ocean-ridge basalt to weak island-arc tholeiite trace element signatures with slight enrichment in large-ion lithophile elements and depletion in high-field-strength elements, high 207Pb/204Pb, and εNd(170 Ma) values of +8.2 to +8.4. The mineralized sequence is conformably overlain by argillaceous sediments and minor limestones. These features, combined with the location of the strata and similarities with the Spider Peak Formation of the Methow terrane, indicate an origin in a narrowing marginal basin that once separated superterranes I and II.
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10

Morrison, A. D., and A. Reay. "Geochemistry of Ferrar Dolerite sills and dykes at Terra Cotta Mountain, south Victoria Land, Antarctica." Antarctic Science 7, no. 1 (March 1995): 73–85. http://dx.doi.org/10.1017/s0954102095000113.

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At Terra Cotta Mountain, in the Taylor Glacier region of south Victoria Land, a 237 m thick Ferrar Dolerite sill is intruded along the unconformity between basement granitoids and overlying Beacon Supergroup sedimentary rocks. Numerous Ferrar Dolerite dykes intrude the Beacon Supergroup and represent later phases of intrusion. Major and trace element data indicate variation both within and between the separate intrusions. Crystal fractionation accounts for much of the geochemical variation between the intrusive events. However, poor correlations between many trace elements require the additional involvement of open system processes. Chromium is decoupled from highly incompatible elements consistent with behaviour predicted for a periodically replenished, tapped and fractionating magma chamber. Large ion lithophile element-enrichment and depletion in Nb, Sr, P and Ti suggests the addition of a crustal component or an enriched mantle source. The trace element characteristics of the Dolerites from Terra Cotta Mountain are similar to those of other Ferrar Group rocks from the central Transantarctic Mountains and north Victoria Land, as well as with the Tasmanian Dolerites. This supports current ideas that the trace element signature of the Ferrar Group is inherited from a uniformly enriched mantle source region.
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11

Sandeman, H. A., B. L. Cousens, and C. J. Hemmingway. "Continental tholeiitic mafic rocks of the Paleoproterozoic Hurwitz Group, Central Hearne sub-domain, Nunavut: insight into the evolution of the Hearne sub-continental lithosphere." Canadian Journal of Earth Sciences 40, no. 9 (September 1, 2003): 1219–37. http://dx.doi.org/10.1139/e03-035.

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The Paleoproterozoic Hurwitz Group of the western Churchill Province is an erosional remnant of an areally extensive, predominantly shallow-water intracratonic basin comprised of four major sequences. Sequence 2, forming the central part of the stratigraphy, contains the Ameto Formation, a sequence of pillowed and massive basaltic rocks and associated gabbro sills termed the Happotiyik Member that are interlayered with subordinate deep-water mudstones, siltstones, and diamictites. Whole-rock geochemical data for the mafic rocks reveals a suite of homogeneous tholeiitic basalts with affinities to both continental and volcanic-arc tholeiites. Compatible trace elements and large-ion lithophile elements exhibit scattered behavior, whereas all high field strength elements show a systematic increase with Zr. The rocks are large-ion lithophile and light rare-earth element enriched, and have parallel primitive mantle normalized extended trace element patterns with prominent negative Nb, Ta, and Ti anomalies. εNd(t=2200 Ma) values for the rocks range from 0.0 to +0.8. The data indicate that the parental magmas were derived from a heterogeneous, predominantly depleted mantle source that included a minor metasomatically enriched component. Contamination by Neoarchean, juvenile silicic upper crust during ascent was minimal. We envisage that the rocks of the Happotiyik Member were generated from sub-continental lithospheric mantle that was stabilized immediately after formation of the ca. 2680 Ma, Neoarchean Central Hearne sub-domain. This enrichment occurred via metasomatic infiltration of subduction-derived fluids and melts into the overlying lithosphere. A wide range of Paleoproterozoic intra-continental mafic rocks in the western Churchill Province exhibit comparable geochemical and isotopic signatures that suggest an origin in the lithospheric mantle. These observations imply that the Hearne sub-continental lithospheric mantle has endured since the Neoarchean and likely persists today.
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12

Raphalalani, Avhatakali, Georges-Ivo Ekosse, John Odiyo, Jason Ogola, and Nenita Bukalo. "Trace Element and Stable Isotope Geochemistry of Lwamondo and Zebediela Kaolins, Limpopo Province, South Africa: Implication for Paleoenvironmental Reconstruction." Minerals 9, no. 2 (February 4, 2019): 93. http://dx.doi.org/10.3390/min9020093.

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The aim of the present study was the paleoenvironmental reconstruction of the prevailing environment under which the Lwamondo and Zebediela kaolin deposits were formed. Hence, this study reports deuterium and oxygen stable isotope values and trace and rare earth element concentrations for two samples of kaolin. Upper continental crust-normalised trace-element patterns reveal that large ion lithophile elements and high-field-strength elements are generally depleted in Lwamondo and Zebediela kaolins, whereas transition trace elements are generally enriched in these kaolins. Upper continental crust-normalised rare earth element (REE) patterns show that there is a slight enrichment of heavy REEs (HREEs) compared to light REEs (LREEs) in these kaolins. The δ18O and δD stable isotope values for kaolinite from Lwamondo ranged from 17.4‰ to 19.1‰ and from −54‰ to 84‰, respectively, whereas those values for kaolinite from Zebediela varied from 15.6‰ to 17.7‰ and from −61‰ to –68‰ for δ18O and δD, respectively. The REE patterns and the content of other trace elements indicate ongoing kaolinitisation in the Lwamondo and Zebediela kaolins with minimum mineral sorting. The sources of the kaolins varied from basic to acidic and these were derived from an active margin tectonic setting. Lwamondo kaolin was deposited in an oxic environment whereas Zebediela kaolin was deposited under suboxic/anoxic conditions. Based on the δ18O and δD values of the kaolinite, they formed in a supergene environment at temperatures generally below 40 °C.
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13

Shevko, E. P., S. B. Bortnikova, N. A. Abrosimova, V. S. Kamenetsky, S. P. Bortnikova, G. L. Panin, and M. Zelenski. "Trace Elements and Minerals in Fumarolic Sulfur: The Case of Ebeko Volcano, Kuriles." Geofluids 2018 (2018): 1–16. http://dx.doi.org/10.1155/2018/4586363.

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Native sulfur deposits on fumarolic fields at Ebeko volcano (Northern Kuriles, Russia) are enriched in chalcophile elements (As-Sb-Se-Te-Hg-Cu) and contain rare heavy metal sulfides (Ag2S, HgS, and CuS), native metal alloys (Au2Pd), and some other low-solubility minerals (CaWO4, BaSO4). Sulfur incrustations are impregnated with numerous particles of fresh and altered andesite groundmass and phenocrysts (pyroxene, magnetite) as well as secondary minerals, such as opal, alunite, and abundant octahedral pyrite crystals. The comparison of elemental abundances in sulfur and unaltered rocks (andesite) demonstrated that rock-forming elements (Ca, K, Fe, Mn, and Ti) and other lithophile and chalcophile elements are mainly transported by fumarolic gas as aerosol particles, whereas semimetals (As, Sb, Se, and Te), halogens (Br and I), and Hg are likely transported as volatile species, even at temperatures slightly above 100°C. The presence of rare sulfides (Ag2S, CuS, and HgS) together with abundant FeS2 in low-temperature fumarolic environments can be explained by the hydrochloric leaching of rock particles followed by the precipitation of low-solubility sulfides induced by the reaction of acid solutions with H2S at ambient temperatures. The elemental composition of native sulfur can be used to qualitatively estimate elemental abundances in low-temperature fumarolic gases.
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14

Dostal, J., G. D. Jackson, and A. Galley. "Geochemistry of Neohelikian Nauyat plateau basalts, Borden rift basin, northwestern Baffin Island, Canada." Canadian Journal of Earth Sciences 26, no. 11 (November 1, 1989): 2214–23. http://dx.doi.org/10.1139/e89-188.

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Subaerial basalt flows of the Neohelikian Nauyat Formation from northwestern Baffin Island, Northwest Territories, constitute an approximately 360 m thick unit that overlies an Archean–Aphebian metamorphic basement. The lavas have undergone a low-grade regional metamorphism that affected the abundances of Na, K, and related trace elements. The basalts are continental tholeiites possessing some characteristics of mid-ocean-ridge basalts. They underwent fractional crystallization of clinopyroxene, plagioclase, and olivine. Mantle-normalized patterns show an enrichment of the lithophile elements, including Th and light rare-earth elements, relative to the high-field-strength elements and a distinct depletion of Nb and Sr. The parental magma of the basalts was derived either from oceanic-type mantle and subsequently affected by lower crustal contamination or from the subcontinental lithospheric mantle. The Nauyat basalts are probably related to the initial stage of the opening of the Poseidon (Proto-Arctic) Ocean.
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15

Rumyantseva, Natalia, Boris Vanshteyn, and Sergey Skublov. "Petrochemical features of tholeiites from the Shaka ridge (South Atlantic)." Journal of Mining Institute 248 (May 25, 2021): 223–31. http://dx.doi.org/10.31897/pmi.2021.2.6.

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The article presents original data of chemical composition of tholeiitic basaltoids and andesites, dredged from the Shaka Ridge (South Atlantic) in the course of field research in spring 2016 on the scientific expedition vessel “Akademik Fedorov”. The analytical part of the work on estimating the contents of petrogenic, trace and rare-earth elements was carried out using the classical method (“wet chemistry”), X-ray fluorescence analysis (XRF) and inductively coupled plasma mass spectrometry (ICP-MS). The studied samples demonstrate elevated concentrations of large-ion lithophile elements, or LILE, (Ba, Rb, Pb) and light rare earth elements, or LREE, (La, Ce, Nd, Sm) relative to high field strength elements, or HFSE, (Nb, Ta) and heavy rare earth elements, or HREE, (Dy, Yb, Lu). The specifics of trace element geochemistry suggest a significant contribution of crustal or subduction components to the magmas of the Shaka Ridge. Discrimination diagrams of basaltoids and allied rocks with fields of different geodynamic settings indicate that they were formed in the setting of the mid-ocean ridge basalt (MORB). The reason behind the appearance of subduction and crustal marks in the rocks is possibly associated with assimilation of crustal matter by magmas or lies in their inheritance from the mantle source.
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16

Martelain, Jacques, Maurice Chenevoy, and Marc Bélanger. "Le batholite de De Pas, Nouveau-Québec : infrastructure composite d'arc magmatique protérozoïque." Canadian Journal of Earth Sciences 35, no. 1 (January 1, 1998): 1–15. http://dx.doi.org/10.1139/e97-084.

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The De Pas Batholith, in New Quebec, is a mass of granitoids elongated in a N-S direction, covering 7000 km2 in the southeastern part of the Archean Rae province. It is located between the Paleoproterozoic New Quebec Orogen in the West and the Torngat Orogen in the East. The batholith is composed, in its south half, of two parallel plutonic units: a charnockitic intrusion in the West, enclosed in granulitic gneisses, and a granitic unit in the East intruding an Archean orthogneiss complex migmatized at amphibolite facies grade. Field evidence indicates that the charnockitic unit is younger than the granitic unit. Both plutonic units are differentiated. The granitic unit ranges in composition from pyroxenite and diorite to the dominant porphyritic granodiorite. The charnockitic unit varies from norite to the dominant porphyritic opdalite. Late intrusive granites are present. The granitic unit and charnockitic unit show calc-alkalic evolutionary trends, granodioritic for the the granitic unit and monzonitic for the charnockitic unit. Similar major elements patterns suggest a common source area. Compatible trace element and heavy rare earth abundances are similar in both units. However, incompatible elements (Rb, Th, and U) and light rare earth are less abundant in the charnockitic unit. This poverty in certain large-ion lithophile elements and high field strength elements is a primary characteristic of the charnockitic magma. The overall geochemical characteristics of the De Pas Batholith are similar to those of a plutonic arc in a subduction setting. Only the late granites show evidence of a collisional setting. The differences in trace elements of the granitic unit and the charnockitic unit might be explained by contrasting styles of contamination of the magmas by continental materials in different intrusive conditions and geological settings. The granitic magma was intruded into Archean (?) crust of amphibolite facies, with which the granitic unit was in physical equilibrium. The charnockitic magma crystallised in the deeper granulitic crust, poor in highly lithophile elements. The De Pas Batholith occurs in the hinterland of the New Quebec Orogen, and represents an early subductional magmatic arc formed in two stages separated by a period of crustal thickening in the arc zone.
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17

Kumar, Naresh, and Naveen Kumar. "Geochemistry of volcanic flows of Nakora area of Malani igneous suite, Northwestern India: Constraints on magmatic evolution and petrogenesis." International Journal of Engineering, Science and Technology 12, no. 1 (April 30, 2020): 66–82. http://dx.doi.org/10.4314/ijest.v12i1.6.

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The geochemical characteristics of volcanic flows of Nakora area of Malani Igneous Suite have been determined to understand their magmatic evolution and petro-genetic aspects. Geochemically, they are high in silica, total alkalis, high field strength elements (HFSE), low ion lithophile elements (LILE), rare metals and rare earth elements; represent A-type affinity with potential mineralization associations. Here, we carried out average geochemical data bank of representative samples of 44 individual lava flows of isolated hill-locks. The relative enrichment of trace elements and negative anomalies of Sr, Eu, P and Ti in the multi-element spider diagrams suggests that the emplacement of the lava flows was controlled by complex magmatic processes i.e. fractional crystallization, partial melting, magma mixing, crustal contamination and assimilation. Moreover, NRCmagma provides new geochemical approaches to understand geodynamic evolution of MIS and emplaced in plume related extensional geodynamic settings in NW Indian shield. Keywords: Geochemistry; Volcanic flows; Nakora; Malani Igneous Suite; Rajasthan; Rodina
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18

Timofeeva, Yana O., Yuliya Kosheleva, Victoria Semal, and Maxim Burdukovskii. "Origin, baseline contents, and vertical distribution of selected trace lithophile elements in soils from nature reserves, Russian Far East." Journal of Soils and Sediments 18, no. 3 (October 10, 2017): 968–82. http://dx.doi.org/10.1007/s11368-017-1847-5.

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19

Dub, S. A., N. V. Cherednichenko, D. V. Kiseleva, N. P. Gorbunova, T. Ya Gulyaeva, and L. K. Deryugina. "Trace element behaviour in acidic leachates (acetic, nitric and hydrochloric) from siliciclastic-carbonate rocks of the Upper Riphean Uk formation in the Southern Urals." LITHOSPHERE (Russia) 19, no. 6 (January 3, 2020): 919–44. http://dx.doi.org/10.24930/1681-9004-2019-19-6-919-944.

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Research subject. 14 samples of limestone and one sample of carbonate-siliciclastic rock from siliciclastic-carbonate deposits of the Upper Riphean Uk Formation (the Southern Urals) were studied.Methods. Mineral and chemical composition of the samples were determined; the main tool for detecting the concentrations of trace elements was the ICPMS method. X-ray diffraction analysis was carried out using a Shimadzu XRD-7000 diffractometer, the content of major (rock-forming) oxides in bulk samples was established by X-ray fluorescence spectrometry on the SRM-35 and Shimadzu XRF 1800 spectrometers. Microelement composition of bulk samples and acidic leachates obtained with using acetic (10%), nitric (36%) and hydrochloric (17%) acids was determined on a Perkin Elmer ELAN 9000 spectrometer.Results. The distribution of lithophile, rare-earth and a number of other elements (Sr, Ni, U) both in bulk samples and in acidic leachates was analyzed. The main carrier phases of these elements were revealed.Conclusions. 1. The use of any listed acids leads to the non-carbonate component entering the solution, including contamination of the “carbonate” leachates by lithophile elements. In particular, a transition Rb, Zr, Li, Th, Ti, Sc to leachates was noted. This process is most active in nitric and hydrochloric acids, less intensive in acetic acid. 2. Among the carriers of rare earth elements (REE) in the studied rocks are clays (1), accessory minerals (2), including phosphate-bearing grains, secondary carbonate phases represented by dolomite and, possibly (3), finely disseminated iron and manganese (oxy)hydroxides (4). It is assumed that the REE pattern in limestones is determined by the content of the epigenetic dolomite. The contribution of lanthanides bound in the sedimentary calcite crystal lattice in the total REE pattern is rather large only in relatively “pure” limestones. However, the use of acids with such concentrations did not allow to obtain a leachate, which the REE pattern with high probability corresponds to the distribution of REE in the Uk time seawater. But acetic acid is more effective for achieving this goal than the others. 3. In addition to Sr, sedimentary calcite also contains Ni and U.
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20

Cameron, B. I., and G. K. Muecke. "Permian alkaline basalts associated with formation of the Sverdrup Basin, Canadian Arctic." Canadian Journal of Earth Sciences 33, no. 10 (October 1, 1996): 1462–73. http://dx.doi.org/10.1139/e96-110.

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Permian basaltic rocks of the Esayoo Formation attended lithospheric extension that formed the Sverdrup Basin in the Canadian Arctic. North of Greely Fiord, northern Ellesmere Island, subaerial flows of the Esayoo Formation attain a maximum thickness of 300 m, but thin rapidly westward, where pillow lavas, epiclastic basalt conglomerate, and associated marine sedimentary rocks indicate proximity to an ancient shoreline. Element-mobility studies demonstrate that modifications of many major elements and some of the large ion lithophile elements accompanied low-grade burial metamorphism. Discriminant diagrams involving only the relatively immobile trace elements reveal within-plate alkaline to transitional basalt affinities. Trace element data (mean Th/Ta = 1.7) do not register significant lower crustal contamination. Models utilizing rare earth clement ratios and Ni–Cr relations suggest that variable degrees of partial melting of an enriched garnet lherzolite and minor combined olivine–clinopyroxene fractional crystallization can account for the described compositional diversity. Nb–Ta peaks (mean La/Nb = 0.99) in spider diagrams identical to ocean-island basalts characterize magmas derived from the asthenospheric mantle with minimal subcontinental lithospheric contribution and continental contamination. Small rates of continental extension during the Carboniferous generated small-volume alkaline melts that passed unadulterated through the subcontinental lithosphere and crust during ascent from their asthenospheric mantle source.
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21

Halley, Scott, John H. Dilles, and Richard M. Tosdal. "Footprints: Hydrothermal Alteration and Geochemical Dispersion Around Porphyry Copper Deposits." SEG Discovery, no. 100 (January 1, 2015): 1–17. http://dx.doi.org/10.5382/segnews.2015-100.fea.

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ABSTRACT Whole-rock lithogeochemical analyses combined with short-wave infrared (SWIR) spectroscopy provide a rapid and cost-effective method for prospecting for porphyry-type hydrothermal systems. Lithogeochemistry detects trace metals to average crustal abundance levels and allows vectoring via gradients of chalcophile and lithophile elements transported by magmatic-hydrothermal ore and external circulating fluids that are dispersed and trapped in altered rocks. Of particular use are alkalis in sericite and metals such as Mo, W, Se, Te, Bi, As, and Sb, which form stable oxides that remain in weathered rocks and soils. SWIR mapping of shifts in the 2,200-nm Al-OH absorption feature in sericite define paleofluid pH gradients useful for vectoring toward the center of the buoyant metal-bearing magmatic-hydrothermal plume.
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22

Ueng, W. C., T. P. Fox, D. K. Larue, and J. T. Wilband. "Geochemistry and petrogenesis of the early Proterozoic Hemlock volcanic rocks and the Kiernan sills, southern Lake Superior region." Canadian Journal of Earth Sciences 25, no. 4 (April 1, 1988): 528–46. http://dx.doi.org/10.1139/e88-052.

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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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Webster, J. D., J. R. Holloway, and R. L. Hervig. "Partitioning of lithophile trace elements between H 2 O and H 2 O + CO 2 fluids and topaz rhyolite melt." Economic Geology 84, no. 1 (February 1, 1989): 116–34. http://dx.doi.org/10.2113/gsecongeo.84.1.116.

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Greenough, John D., Alejandro Velasquez, Mohamed E. Shaheen, Joel Gagnon, Brian J. Fryer, Mikkel Tetland, Yuan Chen, and David Mossman. "Laser ablation ICP–MS trace element composition of native gold from the Abitibi greenstone belt, Timmins, Ontario." Canadian Journal of Earth Sciences 58, no. 7 (July 2021): 593–609. http://dx.doi.org/10.1139/cjes-2019-0134.

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Trace elements in native gold provide a “fingerprint” that tends to be unique to individual gold deposits. Fingerprinting can distinguish gold sources and potentially yield insights into geochemical processes operating during gold deposit formation. Native gold grains come from three historical gold ore deposits: Hollinger, McIntyre (quartz-veined ore), and Aunor near Timmins, Ontario, at the western end of the Porcupine gold camp and the southwestern part of the Abitibi greenstone belt. Laser ablation – inductively coupled plasma – mass spectrometry (LA–ICP–MS) trace element concentrations were determined on 20–25 µm wide, 300 µm long rastor trails in ∼60 native gold grains. Analyses used Ag as an internal standard with Ag and Au determined by a scanning electron microscope with an energy dispersive spectrometer. The London Bullion Market AuRM2 reference material served as the external standard for 21 trace element analytes (Al, As, Bi, Ca, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Pd, Pt, Rh, Sb, Se, Si, Sn, Te, Ti, Zn; Se generally below detection in samples). Trace elements in native gold associate according to Goldschmidt’s classification of elements strongly suggesting that element behaviour in native Au is not random. Such element behaviour suggests that samples from each Timmins deposit formed under similar but slightly variable geochemical conditions. Chalcophile and siderophile elements provide the most compelling fingerprints of the three ore deposits and appear to be mostly in solid solution in Au. Lithophile elements are not very useful for distinguishing these deposits and element concentrations may be controlled by microinclusions such as tourmaline. The deposits show low Ag contents, which is consistent with mesothermal Au. Hollinger and McIntyre deposits have similar trace element abundances with higher Ag, Pb, Bi, Sb, and Pd and generally low Cu; however, Cu concentrations in McIntyre are higher than in Hollinger. In contrast, Aunor shows comparatively low Ag, Bi, Sb, Pb, and Pd and higher Au/Ag consistent with higher hydrothermal fluid temperatures. Gold grain signatures reflect the chemical characteristics of the host rock superimposed on a chemical signature inherited from the mineralizing fluid. The association of Pb–Bi–Cu bearing phases such as galena and chalcopyrite with gold apparently enriched in these elements supports precipitation from hydrothermal fluids carrying the elements.
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James, Elvaene, Azman Abdul Ghani, Oluwatoyin O. Akinola, and Junaidi Asis. "Petrology and Geochemical Features of Semporna Volcanic Rocks, South-east Sabah, Malaysia." Sains Malaysiana 50, no. 1 (January 31, 2021): 9–21. http://dx.doi.org/10.17576/jsm-2021-5001-02.

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The volcanic rocks in Semporna Peninsula, Sabah, Malaysia forms parts of the Miocene subjected slab during the Miocene-Pliocene orogeny. This study presents new petrographic and geochemical data of volcanic rocks in Semporna area. The volcanic rocks range in composition from basaltic andesite, andesite, dacite to rhyolite, with most of the volcanic shows calc-alkaline affinity with a minor tholeiitic feature. The trace elements shows enrichment in large-ion lithophile elements (LILE) and light rare earth elements (LREE) suggesting that the volcanic rocks have similar geochemical patterns and might come from similar magma source. The petrochemical data suggests that volcanic rocks of Semporna shows characteristic of subduction zone (negative Nb, Ta, and Ti). Decreasing magnitude of Europium anomalies from intermediate to acid lavas suggests an important role of plagioclase in the fractional crystallization. Negative Ce anomaly in part of Semporna volcanic rocks suggest that those volcanic rocks may related with emergence of oxygenated deep-sea environment. Tectonic diagrams showed that the Semporna volcanic rocks were formed in an island arc setting.
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Dong, Zhen, Chunhui Tao, Jin Liang, Shili Liao, Wei Li, Guoyin Zhang, and Zhimin Cao. "Geochemistry of Basalts from Southwest Indian Ridge 64° E: Implications for the Mantle Heterogeneity East of the Melville Transform." Minerals 11, no. 2 (February 8, 2021): 175. http://dx.doi.org/10.3390/min11020175.

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As one of the regional, magmatic, robust, axial ridge segments along the ultraslow-spreading Southwest Indian Ridge (SWIR), the magmatic process and mantle composition of the axial high relief at 64° E is still unclear. Here, we present major and trace elements and Sr-Nd-Pb isotope data of mid-ocean ridge basalts (MORBs) from 64° E. The basalts show higher contents of Al2O3, SiO2, and Na2O and lower contents of TiO2, CaO, and FeO for a given MgO content, and depletion in heavy rare-earth elements (HREE), enrichment in large-ion lithophile elements, and lower 87Sr/86Sr, 143Nd/144Nd and higher radiogenic Pb isotopes than the depleted MORB mantle (DMM). The high Zr/Nb (24–43) and low Ba/Nb (3.8–7.0) ratios are consistent with typical, normal MORB (N-MORB). Extensive plagioclase fractional crystallization during magma evolution was indicated, while fractionation of olivine and clinopyroxene is not significant, which is consistent with petrographic observations. Incompatible trace elements and isotopic characteristics show that the basaltic melt was formed by the lower partial melting degree of spinel lherzolite than that of segment #27 (i.e., Duanqiao Seamount, 50.5° E), Joseph Mayes Mountain (11.5° E), etc. The samples with a DMM end-member are unevenly mixed with the lower continental crust (LCC)- and the enriched mantle end-member (EM2)-like components, genetically related to the Gondwana breakup and contaminated by upper and lower continental crust (or continental mantle) components.
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Machevariani, Maria M., Alexey V. Alekseenko, and Jaume Bech. "Complex Characteristic of Zircon from Granitoids of the Verkhneurmiysky Massif (Amur Region)." Minerals 11, no. 1 (January 16, 2021): 86. http://dx.doi.org/10.3390/min11010086.

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The study presents a complex characteristic of zircon from the Verkhneurmiysky intrusive series with Li-F granites. A wide range of morphological and chemical properties of zircon allowed us to obtain new information on the formation and alteration of zircon from biotite and zinnwaldite granitoids and to determine its features, which contribute to the correct definition of Li-F granites formed directly before the tin mineralization. The reviled trends of zircon morphology and composition evolution in the Verkhneurmiysky granites series are: the high-temperature morphotypes are followed by low-temperature ones with more complicated internal structure with secondary alteration zones, mineral inclusions, pores, and cracks; the increasing concentration of volatile (H2O, F), large ion lithophile (Cs, Sr), high field strength (Hf, Nb) and rare-earth elements with decreasing crystallization temperatures and the determining role of the fluid phase (predominantly, F) in the trace element accumulation. The composition of zircon cores in biotite and zinnwaldite granites is very similar. However, the zircon rims from zinnwaldite granites are much more enriched in trace elements compared to those from biotite granites. The first study of zircon from the Verkhneurmiysky granitoids provides new data on the formation and alteration conditions of granitoids, including zinnwaldite ones.
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Zhong, Richen, Min Zhang, Chang Yu, and Hao Cui. "The Fluid Mobilities of K and Zr in Subduction Zones: Thermodynamic Constraints." Minerals 11, no. 4 (April 9, 2021): 394. http://dx.doi.org/10.3390/min11040394.

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A subduction zone plays a critical role in forging continental crust via formation of arc magmas, which are characteristically enriched in large ion lithophile elements (LILEs) and depleted in high field strength elements (HFSEs). This trace element pattern results from the different mobilities of LILEs and HFSEs during slab-to-wedge mass transfer, but the mechanisms of trace element transfer from subducting crusts are not fully understood. In this study, thermodynamic simulations are carried out to evaluate the mobilities of K and Zr, as representative cases of LILE and HFSE, respectively, in slab fluids. The fluids buffered by basaltic eclogite can dissolve > 0.1 molal of K at sub-arc depths (~3 to 5.5 GPa). However, only minor amounts of K can be liberated by direct devolatilization of altered oceanic basalt, because sub-arc dehydration mainly takes place at temperatures < 600 °C (talc-out), wherein the fluid solubility of K is very limited (<0.01 molal). Therefore, serpentinite-derived fluids are required to flush K from the eclogite. The solubility of K can be enhanced by the addition of NaCl to the fluid, because fluid Na+ can unlock phengite-bonded K via a complex ion exchange. Finally, it is further confirmed that Zr and other HFSEs are immobile in slab fluids.
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Patzer, Andrea, Dominik C. Hezel, Verena Bendel, and Andreas Pack. "Chondritic ingredients: II. Reconstructing early solar system history via refractory lithophile trace elements in individual objects of the Leoville CV3 chondrite." Meteoritics & Planetary Science 53, no. 7 (April 15, 2018): 1391–412. http://dx.doi.org/10.1111/maps.13084.

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30

Murao, Satoshi, and Soey H. Sie. "MICRO-PIXE CHARACTERIZATION OF AMORPHOUS SILICA GLOBULES FROM A HYDROTHERMAL FIELD ON THE SEA FLOOR OF OKINAWA, SOUTHERN JAPAN." International Journal of PIXE 10, no. 01n02 (January 2000): 1–10. http://dx.doi.org/10.1142/s012908350000002x.

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During the examination of the representative specimens, a barite ore and a polymetallic chimney, from the JADE hydrothermal field of Okinawa Trough, many amorphous silica globules of approximately 10 to 50 micrometers in diameter were found as isolated sphere or bunchy aggregation. We performed micro-PIXE analyses of the globules to check the effectiveness of the method to such soft and vulnerable material, and to understand the geochemical characteristics. The result shows that amorphous silica can include various kinds of elements in lithophile, chalcophile and siderophile categories. The trace element distribution of the globules indicates that amorphous silica could be a good monitor of geochemical environment; and implies that the chemical variation of ore often found in a mineral field is mainly derived by change in local physicochemical conditions of single mineralizing fluid rather than multiple injection of the solution.
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31

DAHLIN, PETER, ÅKE JOHANSSON, and ULF B. ANDERSSON. "Source character, mixing, fractionation and alkali metasomatism in Palaeoproterozoic greenstone dykes, Dannemora area, NE Bergslagen region, Sweden." Geological Magazine 151, no. 4 (August 13, 2013): 573–90. http://dx.doi.org/10.1017/s0016756813000551.

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AbstractThe geochemical and isotopic characteristics of metamorphosed Svecofennian mafic dykes from the Dannemora area in the NE part of the Bergslagen region in central Sweden were investigated and compared to mafic intrusive rocks in their vicinity. The dykes, with an inferred age of c. 1860–1870 Ma, are calc-alkaline, sub-alkaline and basaltic in composition and have a mixed subduction and within-plate geochemical affinity. They are the result of mixing of at least three mantle source components with similar basaltic major element composition, but different concentrations of incompatible trace elements. Magma M1 is strongly enriched both in Rare Earth Elements (REE) and High-Field-Strength Elements (HFSE); magma M2 is highly enriched in Large-Ion Lithophile Elements (LILE, except Sr) with only moderate enrichment in HFSE and REE (particularly low in Heavy Rare Earth Elements); and magma M3 is enriched in Sr and has a flat REE profile. Magma M3 also has a somewhat more positive (depleted) initial εNd value of +1.8, compared to +0.4 to +0.5 for magmas M1 and M2. The magma evolution was controlled by a mixture of fractionation (mainly affecting the compatible elements) and mixing, best seen in the incompatible element concentrations and the Nd isotope data. The basaltic overall composition indicates little or no wholesale contamination by upper continental crust, but the dykes have undergone later metasomatic changes mainly affecting the alkali elements.
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32

K. Agbenyezi, Theophilus, Gordon Foli, and Simon K. Y. Gawu. "GEOCHEMICAL CHARACTERISTICS OF GOLD-BEARING GRANITOIDS AT AYANFURI IN THE KUMASI BASIN, SOUTHWESTERN GHANA: IMPLICATIONS FOR THE OROGENIC RELATED GOLD SYSTEMS." Earth Science Malaysia 4, no. 2 (June 23, 2020): 127–34. http://dx.doi.org/10.26480/esmy.02.2020.127.134.

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This study investigates auriferous granitoids from the Esuajah and Fobinso pits within the Ayanfuri environment in the Paleoproterozoic Kumasi basin. The aim is to establish the geochemical characteristics of the granitoid gold ores and the possible deposit type which may influence mineral project development. 13 major and 51 trace elements were analyzed using XRF and ICP-MS devices, respectively. The granitoids are mainly classified as granodiorite that crystallized from a calc-alkaline magma series. The Fobinso granodiorite derived from the partial melting of the Birimian metasedimentary rocks, while the Esuajah granitoid derived from igneous rock melts. The granitoid are linked to magma source depleted in mantle material that contains crustal components through subduction processes. Major oxides of the granitoid vary lowly from the average background values derived for basin type granitoid in such terrains. Generally, the granitoid are enriched in Large Ion Lithophile Elements (LILE), while High Field Strength Elements (HFSE) and base metals are within background values when compared to Primitive Mantle (PM) values. Gold mineralisation is associated with Ag, As, Bi, Sb, Te, Pb and S in the peraluminous granitoids. Geochemical characteristics and field observations identify the deposit style as an orogenic related gold deposit type.
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ZHANG, XIAOHUI, HONGFU ZHANG, NENG JIANG, and SIMON A. WILDE. "Contrasting Middle Jurassic and Early Cretaceous mafic intrusive rocks from western Liaoning, North China craton: petrogenesis and tectonic implications." Geological Magazine 147, no. 6 (May 7, 2010): 844–59. http://dx.doi.org/10.1017/s0016756810000373.

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AbstractZircon U–Pb dating, whole-rock major oxide, trace element and Sr–Nd isotopic data are presented for the Late Mesozoic mafic intrusive rocks from Yiwulüshan of western Liaoning along the eastern segment of the Yanshan belt, North China craton, with two episodes of magmatism documented. Middle Jurassic hornblende-rich gabbros show enrichment of large ion lithophile elements and light REE, and prominent depletion in high field strength elements, and possess moderately enriched isotopic compositions with (87Sr/86Sr)i ranging from 0.7056 to 0.7065 and ɛNd(t) from −5.0 to −7.1. These features suggest that the gabbros were derived from an amphibole-bearing harzburgitic lithospheric mantle source metasomatized recently by slab-derived fluids. By contrast, Early Cretaceous mafic dykes are gabbroic dioritic to dioritic in composition, with comparable trace element characteristics to continental crust and depleted isotopic signatures ((87Sr/86Sr)i = 0.7048–0.7055, ɛNd(t) = 0 to −3.0). They probably originated from partial melting of a relatively fertile asthenospheric mantle in the spinel stability field, with subsequent lower crustal assimilation and fractional crystallization. These two contrasting mafic intrusive suites, together with multiple Mesozoic mafic volcanic rocks from western Liaoning, documented a localized lithospheric thinning process, mainly through prolonged hydro-weakening or melt–rock interaction and triggered by gravitational collapse, possibly within an evolved post-collisional to within-plate extensional regime.
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34

Bowerman, Melissa, Amy Christianson, Robert A. Creaser, and Robert W. Luth. "A petrological and geochemical study of the volcanic rocks of the Crowsnest Formation, southwestern Alberta, and of the Howell Creek suite, British Columbia." Canadian Journal of Earth Sciences 43, no. 11 (November 1, 2006): 1621–37. http://dx.doi.org/10.1139/e06-037.

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Alkaline igneous rocks of the Crowsnest Formation in southwestern Alberta and in the Howell Creek area in southeastern British Columbia have been suggested previously to be cogenetic. To test this hypothesis, samples of both suites were characterized petrographically and their major and trace element geochemistry was determined. A subset of the samples was analyzed for whole-rock Sr and Nd isotope geochemistry. The samples of the two suites are latites, trachytes, and phonolites based on the International Union of Geological Sciences (IUGS) total alkalis versus silica (TAS) diagram. Samples from both suites show similar patterns on mantle-normalized trace element diagrams, being enriched relative to mantle values but depleted in the high field-strength elements Nb, Ta, and Ti relative to the large-ion lithophile elements. The chondrite-normalized rare-earth element (REE) patterns for both suites are light REE enriched, with no Eu anomaly and flat heavy REE. The isotope geochemistry of both suites is characterized by low initial 87Sr/86Sr (SrT = 0.704 to 0.706) and low εNdT (–7 to –16). The Howell Creek samples have lower εNdT and higher SrT than do the Crowsnest samples. Based on the intra- and intersuite differences in the isotope geochemistry, we conclude that these samples are not cogenetic, but rather represent samples that have experienced similar evolutionary histories from a heterogeneous source region in the subcontinental lithospheric mantle.
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35

Oluyede, Kehinde, and Urs Klötzli. "Syn-collisional pan-African granite in the northern part Birnin Gwari schist belt in NW Nigeria." International Journal of Advanced Geosciences 8, no. 2 (September 30, 2020): 197. http://dx.doi.org/10.14419/ijag.v8i2.31095.

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Syn-collisional granite in the northern part of the Birnin Gwari schist belt consists dominantly of granite and lesser granodiorite and quartzolite. Petrographic and ge¬ochemical data revealed three granite groups: the biotite-hornblende granite (quartzolite - BHG); the biotite granite (BG) and the biotite-muscovite granite (BMG). The rocks generally have calc-alkaline and high-K calc-alkaline affinities, and calc-alkalic to alkali-calcic, peraluminous and ferroan and magnesian geochemistry. They are characterized by LILE enrichment, high LREE fractionation factor [(La/Yb) (6.74 to 45.14] with weak to moderate negative Eu (Eu/Eu* = 0.38 to 0.62) and strong negative Nb, P and Ti anomalies. Variation in the behavior of lithophile elements (Ba, Sr and Rb) revealed diverse granite trend such as “high and low Ba-Sr”; “normal”, “anomalous” “strongly differentiated” and “granodiorite and quartz diorite” granite. Their display of similar trace elements and REE patterns suggest they are cogenetic. Major and trace element data indicate differentiation of a mafic magma and partial melting of crustal components inherited from shale-greywacke and quartzose sedimentary protoliths in volcanic arc and post collisional settings. The field and geochemical characteristics of this granite suggest that they are similar to other granites in schist belts in other parts of Nigeria, forming the lateral continuation of the same Pan-African magmatic belt.
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White, John Charles. "Trace-element partitioning between alkali feldspar and peralkalic quartz trachyte to rhyolite magma. Part II: Empirical equations for calculating trace-element partition coefficients of large-ion lithophile, high field-strength, and rare-earth elements." American Mineralogist 88, no. 2-3 (February 2003): 330–37. http://dx.doi.org/10.2138/am-2003-2-310.

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GUO, FENG, WEIMING FAN, and CHAOWEN LI. "Geochemistry of late Mesozoic adakites from the Sulu belt, eastern China: magma genesis and implications for crustal recycling beneath continental collisional orogens." Geological Magazine 143, no. 1 (November 15, 2005): 1–13. http://dx.doi.org/10.1017/s0016756805001214.

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Both low-Al and high-Al adakitic andesites erupted at ∼ 114 Ma in the Sulu collisional belt, eastern China, provide evidence for recycling of continental crust into the mantle more than 100 million years after the Triassic (∼ 240 Ma) collision between the North China and Yangtze blocks. These rocks display similar normalized trace element patterns, with enrichments in large ion lithophile elements (LILE), light rare earth elements (LREE) and depletions in Nb, Ta and Ti, and have highly radiogenic Sr and non-radiogenic Nd isotopic compositions (high-Al: 87Sr/86Sr(i)=0.70645–0.70715 and εNd(t)=−20.1 to −19.1; low-Al: 87Sr/86Sr(i)=0.70593–0.70598 and εNd(t)=−17.1 to −15.8). The high-Al (Al2O3 > 15 %) adakitic andesites are compositionally comparable with experimental slab melts, whereas the low-Al series (Al2O3 ∼ 13 %) have higher MgO, Cr and Ni, and higher Sr/Y ratios, and are compositionally comparable with slab melts hybridized by mantle peridotites. Combined major- and trace-element and Sr–Nd isotope data indicate that the two types of adakitic andesites have been derived from a LILE- and LREE-enriched eclogitic lower continental crust; in the case of the high-Al adakitic andesites, the melts underwent insignificant mantle contamination, whereas the low-Al magmas reacted with peridotites. Generation of the two types of late Mesozoic adakitic andesites favours a model of lithospheric delamination, leading to asthenospheric upwelling and extensive melting of lower continental crust, including a delaminated block, in the Sulu belt.
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38

Wei, An Jun, Bai Lin Wu, Ben Hao Zhang, Zi Sheng Song, Hai Tong Wang, Dan Wang, Xiao Ni Cun, and Li Sun. "Geological and Geochemical Characteristics of Chang 7 Uranium-Enriched Hydrocarbon Source Rocks in Ordos Basin and the Possible Reasons for its Formation." Applied Mechanics and Materials 551 (May 2014): 16–22. http://dx.doi.org/10.4028/www.scientific.net/amm.551.16.

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The Ordos basin Chang 7 hydrocarbon source rocks are the most important rock strata of premium oil source formed during the largest lake flood period of the terrestrial lacustrine. Our study found that the bottom of the rocks are rich in radioactive uranium. Element geochemical studies showed that the rocks are also rich in C, S, P, Cu, V, Mo and other pro-life elements but not rock-forming minerals-related lithophile elements Li, Zr, Sr, etc. Their uranium content has obvious positive correlation with phosphorus, sulfur, iron, organic carbon content, but not with major rock-forming elements. Petrography and scanning electron microscopy revealed the rocks are rich in pyrite, phosphate rock and striped organic matters. These features indicate that uranium enrichment and the presence of these minerals are closely related. The significantly positive correlation of the ratio of uranium to trace elements such as U/ (U+Ni) and U/Sc indicates that anoxic environment played an important role in uranium enrichment. Electron microprobe analysis found for the first time uranium ore and independent titanium-containing uranium minerals in phosphate rocks in the area. α radiation photography and sequential chemical extraction found that 50% of uranium present as independent uranium and its isomorphic minerals in the phosphate rocks, 20% is absorbed to pyrite and organic matter, and less than 10% is absorbed on clay minerals.
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39

Manga, Veronica Ebot, Gladys Nchang Neba, and Emmanuel Cheo Suh. "Environmental Geochemistry of Mine Tailings Soils in the Artisanal Gold Mining District of Betare -Oya, Cameroon." Environment and Pollution 6, no. 1 (March 31, 2017): 52. http://dx.doi.org/10.5539/ep.v6n1p52.

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Changes in trace element concentrations in mine tailings (dry and wet) were investigated in the gold mining area of Bétaré-Oya, Eastern Cameroon. Forty-one surface sediment samples were analyzed using ICP-MS for heavy metals and pollution was assessed using Enrichment Ratio and Geo Accumulation Index (Igeo); using a sample from a remote area as control.Trace elements in mine tailings show significant increase compared to the background (control) values, with the exception of Sr and Nb. It is suggested that allochtonous deposition may account for Sr distribution. A strong correlation is observed between the lithophile elements; Y, Nb, Ce, La, and Pb. Their association with each other is also strong, i.e. Nb/Ce (.73) and La/Ce (.63). The close association of these elements in the samples may be an indication of the effect of resistant heavy minerals from felsic rocks (mainly granites and gneisses). Cu, Zn, Sr and Ba distribution is associated with mineralisation of sulphide-bearing minerals and clay formation from weathering of mica schist. Cu, Zn, As, W, Mo and Ag have been identified as potential pollutants. Compared to the Dutch soil quality guidelines, these elements are above the target values and below the intervention levels. Arsenic is considered to be the most threatening element, with regards to its potency. The distribution of As in this area appears to be controlled by mining activities.
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40

Vedana, Luiz Alberto, Ruy Paulo Philipp, and Carlos Augusto Sommer. "Post-collisional basalts of the Acampamento Velho Formation, Camaquã Basin, São Gabriel Terrane, southernmost Brazil." Brazilian Journal of Geology 47, no. 3 (September 2017): 467–89. http://dx.doi.org/10.1590/2317-4889201720170019.

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ABSTRACT: The basic volcanic rocks in the Palma region, southern portion of the São Gabriel Terrane, have always been interpreted as generated during the active subduction period of the São Gabriel orogeny (Cryogenian). This terrane was built as the result of the Charrua Ocean closure between 900-680 Ma. The basalts show a subhorizontal igneous flow foliation and porphyritic texture, with plagioclase phenocrysts in a thin matrix composed of plagioclase, augite and magnetite, commonly altered to actinolite, chlorite and epidote. They have amygdales and veinlets reflecting a pervasive hydrothermal phase and are affected by thermal metamorphism related to Jaguari granite intrusion. Two samples were dated by the U-Pb zircon geochronology and yielded crystallization ages of 563±2 Ma and 573±6 Ma. The basalts have transitional composition from tholeiitic to calc-alkaline, metaluminous character, trace elements patterns rich in large-ion lithophile element (LILE) with negative anomalies of Nb, P and Ti, slight enrichment in light rare-earth elements (LREE) and horizontal pattern of heavy rare earth elements (HREE). The data allow interpreting the basalts as belonging to the Acampamento Velho Formation of the Camaquã Basin, and related to the basalts of the Ramada and Taquarembó plateaus. These associations represent the final evolution of the volcanism generated in the post-collisional period of the Dom Feliciano Belt.
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Agangi, Andrea, Vadim S. Kamenetsky, and Jocelyn McPhie. "The role of fluorine in the concentration and transport of lithophile trace elements in felsic magmas: Insights from the Gawler Range Volcanics, South Australia." Chemical Geology 273, no. 3-4 (May 2010): 314–25. http://dx.doi.org/10.1016/j.chemgeo.2010.03.008.

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42

Sutherland, F. L., R. R. Coenraads, A. Abduriyim, S. Meffre, P. W. O. Hoskin, G. Giuliani, R. Beattie, R. Wuhrer, and G. B. Sutherland. "Corundum (sapphire) and zircon relationships, Lava Plains gem fields, NE Australia: Integrated mineralogy, geochemistry, age determination, genesis and geographical typing." Mineralogical Magazine 79, no. 3 (June 2015): 545–81. http://dx.doi.org/10.1180/minmag.2015.079.3.04.

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AbstractGem minerals at Lava Plains, northeast Queensland, offer further insights into mantle-crustal gemformation under young basalt fields. Combined mineralogy, U-Pb age determination, oxygen isotope and petrological data on megacrysts and meta-aluminosilicate xenoliths establish a geochemical evolution in sapphire, zircon formation between 5 to 2 Ma. Sapphire megacrysts with magmatic signatures (Fe/Mg ∼100–1000, Ga/Mg 3–18) grew with ∼3 Ma micro-zircons of both mantle (δ18O 4.5–5.6%) and crustal (δ18O 9.5–10.1‰) affinities. Zircon megacrysts (3±1 Ma) show mantle and crustal characteristics, but most grew at crustal temperatures (600–800°C). Xenolith studies suggest hydrous silicate melts and fluids initiated from amphibolized mantle infiltrated into kyanite+sapphire granulitic crust (800°C, 0.7 GPa). This metasomatized the sapphire (Fe/Mg ∼50–120, Ga/Mg ∼3–11), left relict metastable sillimanite-corundum-quartz and produced minerals enriched in high field strength, large ion lithophile and rare earth elements. The gem suite suggests a syenitic parentage before its basaltic transport. Geographical trace-element typing of the sapphire megacrysts against other eastern Australian sapphires suggests a phonolitic involvement.
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43

Wang, Shengdong, Xiaohong Deng, Peng Dai, Junjie Wu, Jie Zhang, Quan Zhang, and Zhong Wang. "Geochemistry and mineralogy of Quaternary sediments in the northern Bohai Bay Basin, North China: implications for provenance and climate change." Canadian Journal of Earth Sciences 57, no. 3 (March 2020): 396–406. http://dx.doi.org/10.1139/cjes-2018-0213.

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The Bohai Bay Basin, located in the eastern North China Block, is an important sedimentary basin for studying the Quaternary climate and environment of northern China. Although sporo-pollen analyses have been used to study the paleoclimate, quantitative research via geochemistry had not been conducted. The sedimentary sequence, geochemistry, and mineralogy of Quaternary sediments from core GJ01 in the Yongding River fluvial plain, northern Bohai Bay Basin, were studied to determine their provenance and investigate climate change during the Quaternary. The stratigraphic sequence of the Quaternary was mainly formed by fluviation by a meandering river, showing a typical dual structure. The sediments have relatively high SiO2 and CaO concentrations, and low Al2O3, Na2O, and Fe2O3T concentrations. In terms of trace elements, most large ion lithophile elements are slightly enriched, and Rb and K concentrations are close to those of post-Archean Australian shale (PAAS); most high field strength elements are slightly to moderately depleted. Rare earth elements (REEs) vary significantly, with light rare earth elements (LREEs) obviously enriched relative to heavy rare earth elements (HREEs). A slightly negative Eu anomaly is present, with nearly no Ce anomaly. Mineralogical analysis shows that the main minerals in the fine-grained sediments are quartz, plagioclase, and K-feldspar. The geochemistry and mineralogy of the sediments indicate that the main provenances were recycled sedimentary rocks and felsic igneous rocks. The sediments have low chemical index of alteration (CIA) values, demonstrating that the source rocks underwent slight weathering. The mean annual precipitation and temperature of the studied area during the Quaternary varied from 531 to 875 mm and from 4.1 to 11.8 °C, respectively.
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44

Nie, Xi-Tao, Jing-Gui Sun, Feng-Yue Sun, Bi-Le Li, Ya-Jing Zhang, and Wan-Zhen Liu. "Zircon U–Pb and molybdenite Re–Os dating and geological implications of the Shimadong porphyry molybdenum deposit in eastern Yanbian, northeastern China." Canadian Journal of Earth Sciences 57, no. 5 (May 2020): 630–46. http://dx.doi.org/10.1139/cjes-2019-0014.

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The Shimadong porphyry Mo deposit is located in eastern Yanbian, in the eastern part of the north margin of the North China craton, northeastern China. Here, we present the whole-rock major and trace elements, zircon U–Pb and Hf isotope data, and molybdenite Re–Os data for the Shimadong deposit. The porphyry was emplaced at 163.7 ± 0.9 Ma and the mineralization at 163.1 ± 0.9 Ma, suggesting that the mineralization was associated with the emplacement of the Shimadong porphyritic monzogranite. The porphyritic monzogranite had high SiO2 (70.09–70.55 wt%) and K2O + Na2O (7.98–8.27 wt%) contents and low MgO (0.51–0.53 wt%), TFeO (2.4–2.47 wt%), CaO (2.19–2.26 wt%), and K2O/Na2O (0.8–0.82) contents. The porphyry was rich in large ion lithophile elements Rb, Ba, K, and Sr, depleted in high-field-strength elements Y, Nb, Ta, P, and Ti, without significant Eu anomaly (δEu = 0.86–1.00), and depleted in heavy rare earth elements with light rare earth elements/heavy rare earth elements = 18.25–20.72 and (La/Yb)N = 27.10–34.67. These features are similar to those of adakitic rocks derived from a thickened lower crust. Zircon εHf(t) values for the porphyritic monzogranite ranged from –19.2 to 6.3, and the two-stage Hf model ages (TDM2) were 2421–811 Ma. These data indicate that the primary magma of the Shimadong porphyritic monzogranite was mainly derived from partial melting of the thickened lower crust consisting of juvenile crust and pre-existing crust. Combined with the results of previous studies, our data suggest that the Shimadong porphyry Mo deposit was emplaced along an active continental margin related to the westward subduction of the paleo-Pacific Plate.
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45

ZENG, QING-DONG, JIN-HUI YANG, JIAN-MING LIU, SHAO-XIONG CHU, XIAO-XIA DUAN, ZUO-LUN ZHANG, WEI-QING ZHANG, and SONG ZHANG. "Genesis of the Chehugou Mo-bearing granitic complex on the northern margin of the North China Craton: geochemistry, zircon U–Pb age and Sr–Nd–Pb isotopes." Geological Magazine 149, no. 5 (November 24, 2011): 753–67. http://dx.doi.org/10.1017/s0016756811000987.

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AbstractThe Chehugou granite-hosted molybdenum deposit is typical of the Xilamulun metallogenic belt, which is an important Mo–Ag–Pb–Zn producer in China. A combination of major and trace element, Sr and Nd isotope, and zircon U–Pb isotopic data are reported for the Chehugou batholith to constrain its petrogenesis and Mo mineralization. The zircon SIMS U–Pb dating yields mean ages of 384.7 ± 4.0 Ma and 373.1 ± 5.9 Ma for monzogranite and syenogranite and 265.6 ± 3.5 Ma and 245.1 ± 4.4 Ma for syenogranite porphyry and granite porphyry, respectively. The Devonian granites are calc-alkaline with K2O/Na2O ratios of 0.44–0.52, the Permian granites are alkali-calcic with K2O/Na2O ratios of 1.13–1.25, and the Triassic granites are calc-alkaline and alkali-calcic rocks with K2O/Na2O ratios of 0.78–1.63. They are all enriched in large-ion lithophile elements (LILEs) and depleted in high-field-strength elements (HFSEs) with negative Nb and Ta anomalies in primitive mantle-normalized trace element diagrams. They have relatively high Sr (189–1256 ppm) and low Y (3.87–5.43 ppm) concentrations. The Devonian granites have relatively high initial Sr isotope ratios of 0.7100–0.7126, negative ɛNd(t) values of −12.3 to −12.4 and 206Pb/204Pb ratios of 16.46–17.50. In contrast, the Permian and Triassic granitoids have relatively low initial 87Sr/86Sr ratios (0.7048–0.7074), negative ɛNd(t) values of −10.1 to −13.1 and 206Pb/204Pb ratios of 17.23–17.51. These geochemical features suggest that the Devonian, Permian and Triassic Chehugou granitoids were derived from ancient, garnet-bearing crustal rocks related to subduction of the Palaeo-Asian Ocean and subsequent continent–continent collision between the North China and Siberian plates.
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46

Wiszniewska, Janina, Anna Grabarczyk, Ewa Krzemińska, and Talat Ahmad. "Contribution to the Mineral Chemistry of the Proterozoic Aravalli Mafic Meta-Volcanic Rocks from Rajasthan, NW India." Minerals 10, no. 7 (July 18, 2020): 638. http://dx.doi.org/10.3390/min10070638.

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Field, petrological and mineral chemistry for meta-volcanic rocks from the Aravalli sequence (Aravalli Craton, India) are presented. Field evidence such as volcanic flows and suspect pillow lava structures, dominant Fe-tholeiite lava flows intercalated with quartzites and argillaceous sediments, indicate rift tectonic environment. Primary mineralogy was obliterated during post-magmatic processes such as metamorphism corresponding to the greenschist to lower amphibolite facies conditions. The rock’s mineral composition was overprinted by plagioclase–chlorite–amphibole–epidote assemblage. The relicts of clinopyroxene were observed. The P-T estimation indicates a temperature of 550–600 °C for the pressure ranging from 3.0 to 7.0 kbar for the majority of amphiboles and 8.0–10.7 kbar for the minority. Geochemically, these rocks are komatiitic (picritic) and high-Fe tholeiitic basalts with 45.06−59.2 wt.% SiO2 and MgO content from 5 to 22.4 wt.% and Mg# of 17 to 71. They show large-ion lithophile elements (LILE) and light rare-earth elements (LREE) enrichment. Chondrite normalized rare-earth elements (REE) patterns for the Aravalli lava are moderately enriched with (La/Sm)N = 1.1−3.85, (La/Yb)N from 1.49 (komatiites) to 14.91 (komatiitic basalts). The trace element systematics with the negative Nb, P and Zr anomalies reflect their derivation from enriched sub-continental lithospheric sources, although minor crustal contamination cannot be ruled out. Aravalli rocks are considered to represent the transition from continental rift magmatism to shallow submarine eruption.
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47

MEYER, ROMAIN, GRAEME R. NICOLL, JAN HERTOGEN, VALENTIN R. TROLL, ROBERT M. ELLAM, and C. HENRY EMELEUS. "Trace element and isotope constraints on crustal anatexis by upwelling mantle melts in the North Atlantic Igneous Province: an example from the Isle of Rum, NW Scotland." Geological Magazine 146, no. 3 (February 27, 2009): 382–99. http://dx.doi.org/10.1017/s0016756809006244.

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AbstractSr and Nd isotope ratios, together with lithophile trace elements, have been measured in a representative set of igneous rocks and Lewisian gneisses from the Isle of Rum in order to unravel the petrogenesis of the felsic rocks that erupted in the early stages of Palaeogene magmatism in the North Atlantic Igneous Province (NAIP). The Rum rhyodacites appear to be the products of large amounts of melting of Lewisian amphibolite gneiss. The Sr and Nd isotopic composition of the magmas can be explained without invoking an additional granulitic crustal component. Concentrations of the trace element Cs in the rhyodacites strongly suggests that the gneiss parent rock had experienced Cs and Rb loss prior to Palaeogene times, possibly during a Caledonian event. This depletion caused heterogeneity with respect to87Sr/86Sr in the crustal source of silicic melts. Other igneous rock types on Rum (dacites, early gabbros) are mixtures of crustal melts and and primary mantle melts. Forward Rare Earth Element modelling shows that late stage picritic melts on Rum are close analogues for the parent melts of the Rum Layered Suite, and for the mantle melts that caused crustal anatexis of the Lewisian gneiss. These primary mantle melts have close affinities to Mid-Oceanic Ridge Basalts (MORB), whose trace element content varies from slightly depleted to slightly enriched. Crustal anatexis is a common process in the rift-to-drift evolution during continental break-up and the formation of Volcanic Rifted Margins systems. The ‘early felsic–later mafic’ volcanic rock associations from Rum are compared to similar associations recovered from the now-drowned seaward-dipping wedges on the shelf of SE Greenland and on the Vøring Plateau (Norwegian Sea). These three regions show geochemical differences that result from variations in the regional crustal composition and the depth at which crustal anatexis took place.
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48

Shang, Zhi, and Yongqing Chen. "Zircon U–Pb Geochronology, Geochemistry and Geological Significance of the Anisian Alkaline Basalts in Gejiu District, Yunnan Province." Minerals 10, no. 11 (November 18, 2020): 1030. http://dx.doi.org/10.3390/min10111030.

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The Gejiu Anisian alkaline basalts (GAAB), distributed in the southern part of the Emeishan large igneous province (ELIP), are crucial to understand the tectonomagmatic activity during the Triassic. Geochronological, geochemical, and Sr-Nd-Pb isotopic analyses were systematically applied to explore the origin, petrogenesis, and tectonic setting of the GAAB, and how they relate to the ELIP. Zircon U-Pb dating set the eruption date at 244 Ma. Most of the samples belonged to alkaline basalts and had high TiO2 (2.14–3.23 wt.%) and MgO (4.43–19.58 wt.%) contents. Large ion lithophile elements (LILEs) were enriched relative to high field strength elements (HFSEs). The rare earth elements (REEs) and trace element signatures in the normalized diagrams were similar to oceanic island basalts (OIB) and Emeishan high-Ti basalts. These samples had consistent Sr-Nd isotope compositions: the initial 87Sr/86Sr values ranged from 0.7044 to 0.7048 and εNd(t) = 3.25–4.92. The Pb isotopes were more complex, the (206Pb/204Pb)t, (207Pb/204Pb)t, (208Pb/204Pb)t ratios were 17.493–18.197, 15.530–15.722, and 37.713–38.853, respectively. Our results indicate that the GAAB originated from the deeper enriched mantle with 5% to 15% partial melting of garnet lherzolite and a segregation depth of 2 to 4 GPa (60–120 km). During the formation of the GAAB, clinopyroxene and Ti-Fe oxides were fractionally crystallized with insignificant crustal contamination. The GAAB were formed in a extensional regime that was related to the Gejiu-Napo rift event in the Triassic.
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49

Moazzen, Mohssen, Zohreh Salimi, Yann Rolland, Michael Bröcker, and Robab Hajialioghli. "Protolith nature and P–T evolution of Variscan metamorphic rocks from the Allahyarlu complex, NW Iran." Geological Magazine 157, no. 11 (March 18, 2020): 1853–76. http://dx.doi.org/10.1017/s0016756820000102.

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AbstractMetamorphic rocks associated with ophiolitic rocks occur on the eroded surface of a NW–SE-trending anticline in the Allahyarlu area, NW Iran, between the Caucasus and Zagros orogenic belts. Metapelitic rocks consist mainly of quartz, muscovite chlorite, altered biotite and garnet. S1 is the pervasive schistosity, wrapping garnet, which is folded by the second schistosity (S2). The amphibolite records only one phase of deformation as the main lineation. The rocks experienced metamorphism up to the amphibolite facies, then overprinted by greenschist facies condition. Thermobarometry indicates an average pressure of c. 5 kbar and an average temperature of c. 600 °C for the amphibolite facies metamorphism, corresponding to a ∼33 °C km−1 geothermal gradient in response to a thick magmatic arc setting. Greenschist facies metamorphism shows re-equilibration of the rocks during exhumation. Amphibolites whole rock geochemistry shows trace elements patterns similar to both island arc and back-arc basin basalts, suggesting that the protolith-forming magma of the amphibolites was enriched at shallow to medium depth of a subduction system. Negative Nb anomaly and slight enrichment in light rare earth elements (LREE) and large-ion lithophile elements (LILE) of the amphibolites indicate arc-related magmatism for their protolith and a back-arc sialic setting for their formation. 40Ar–39Ar dating on muscovite separated from two gneiss samples, and hornblende separated from three amphibolite samples, documents a Variscan (326–334 Ma) age. The magmatic and metamorphic rock association of the Allahyarlu area suggests the existence of an active continental margin arc during the Variscan orogeny, without clear evidence for a continental collision.
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50

Harsini, Azam Entezari, Seyed A. Mazaheri, Saeed Saadat, and José F. Santos. "U-Pb geochronology, Sr-Nd geochemistry, petrogenesis and tectonic setting of Gandab volcanic rocks, northeastern Iran." Geochronometria 44, no. 1 (November 16, 2017): 269–86. http://dx.doi.org/10.1515/geochr-2015-0061.

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Abstract This paper addresses U-Pb geochronology, Sr-Nd geochemistry, petrogenesis and tectonic setting in the Gandab volcanic rocks. The Gandab volcanic rocks belong to the Sabzevar zone magmatic arc (northeastern Iran). Petrographically, all the studied volcanic rocks indicate porphyritic textures with phenocrysts of plagioclase, K-feldespar, hornblende, pyroxene, and magnetite which are embedded in a fine to medium grained groundmass. As well, amygdaloidal, and poikilitic textures are seen in some rocks. The standard chemical classifications show that the studied rocks are basaltic trachy andesite, trachy andesite, trachyte, and trachy dacite. Major elements reveal that the studied samples are metaluminous and their alumina saturation index varies from 0.71 to 1.02. The chondrite-normalized rare earth element and mantle-normalized trace element patterns show enrichment in light rare earth elements (LREE) relative to heavy rare earth elements (HREE) and in large ion lithophile elements (LILE) relative to high field strength elements (HFSE). As well they show a slightly negative Eu anomaly (Eu/Eu* = 0.72 – 0.97). The whole-rock geochemistry of the studied rocks suggests that they are related to each other by fractional crystallization. LA-MC-ICP-MS U-Pb analyses in zircon grains from two volcanic rock samples (GCH-119 and GCH-171) gave ages ranging of 5.47 ± 0.22 Ma to 2.44 ± 0.79 Ma, which corresponds to the Pliocene period. In four samples analysed for Sr and Nd isotopes 87Sr/86Sr ratios range from 0.704082 to 0.705931 and εNd values vary between +3.34 and +5. These values could be regarded to as representing mantle derived magmas. Taking into account the comparing rare earth element (REE) patterns, an origin of the parental magmas in enriched lithospheric mantle is suggested. Finally, it is concluded that Pliocene Gandab volcanic rocks are related to the post-collision environment that followed the Neo-Tethys subduction.
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