Journal articles: 'Magmatisme – Islande'

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Widana, Kurnia Setiawan, and Bambang Priadi. "Karakteristik Unsur Jejak Dalam Diskriminasi Magmatisme Granitoid Pulau Bangka." EKSPLORIUM 36, no. 1 (May 30, 2015): 1. http://dx.doi.org/10.17146/eksplorium.2015.36.1.2766.

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Geologi Pulau Bangka disusun oleh variasi granit sebagai Granitoid Klabat yang tersebar di berbagai lokasi. Unsur jejak dapat diaplikasikan dalam diskriminasi magmatisme dalam pembentukan granitoid tersebut. Tujuan penelitian ini adalah mengetahui karakteristik granitoid yang tersebar di Pulau Bangka berdasarkan geokimia unsur jejak untuk diaplikasikan dalam mempelajari magmatisme, sumber dan situasi tektoniknya.Metode analisis geokimia yang diaplikasikan dengan menggunakan Analisis Aktivasi Neutron (AAN) dan portableX-Ray Fluorescence (pXRF) untuk analisis kualitatif dan kuantitatif pada 27 sampel dari Granitoid Klabat di Pulau Bangka.Hasil penelitian ini menyimpulkan Granitoid Bangka Utara (Belinyu) dan Bangka Tengah sebagai percampuran kerak-mantel dengan afinitas Calc-Alkaline, karakteristik Tipe I sedangkan Granitoid Bangka Selatan dan Barat asal kerak dengan afinitas High-KCalc-Alkaline sebagai Tipe S. Diharapkan diskrimasi magmatisme granitoid bermanfaat dalam memberikan panduan eksplorasi bahan galian nuklir di Pulau Bangka. Geology of Bangka Island consists by variation of granite as Klabat Granitoid scattered in various locations. Trace elements can be applied in magmatism discrimination of granitoid.The purpose of this study was to determine the characteristics Bangka Island granitoid based on trace element geochemistry to be applied in the study of magmatism, source and tectonic situation. Geochemical analyses method used are the Neutron Activation Analysis (NAA) and portableX-Ray Fluorescence (pXRF) for qualitative and quantitative analyses on 27 samples of Klabat granitoid on Bangka Island. This study concluded granitoid East Bangka (Belinyu) and Central Bangka as crust-mantle mixing with affinityCalc-Alkaline, characteristic of I Type while South and West Bangka granitoid crust origin with affinity high K Calc-Alkaline as S Type. Expectedmagmatismdiscrimination ofgranitoidhelpfulin providingradioactive mineral explorationguidein BangkaIsland.

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Kuzmichev, A. B., and A. E. Goldyrev. "Permian-Triassic trap magmatism in Bel'kov Island (New Siberian Islands)." Russian Geology and Geophysics 48, no. 2 (February 2007): 167–76. http://dx.doi.org/10.1016/j.rgg.2007.02.002.

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Obst, Karsten. "Permo-Carboniferous dyke magmatism on the Danish island Bornholm." Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 218, no. 1-2 (October 1, 2000): 243–66. http://dx.doi.org/10.1127/njgpa/218/2000/243.

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Riley, T. R., M. J. Flowerdew, R. J. Pankhurst, P. T. Leat, I. L. Millar, C. M. Fanning, and M. J. Whitehouse. "A revised geochronology of Thurston Island, West Antarctica, and correlations along the proto-Pacific margin of Gondwana." Antarctic Science 29, no. 1 (August 30, 2016): 47–60. http://dx.doi.org/10.1017/s0954102016000341.

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AbstractThe continental margin of Gondwana preserves a record of long-lived magmatism from the Andean Cordillera to Australia. The crustal blocks of West Antarctica form part of this margin, with Palaeozoic–Mesozoic magmatism particularly well preserved in the Antarctic Peninsula and Marie Byrd Land. Magmatic events on the intervening Thurston Island crustal block are poorly defined, which has hindered accurate correlations along the margin. Six samples are dated here using U-Pb geochronology and cover the geological history on Thurston Island. The basement gneisses from Morgan Inlet have a protolith age of 349±2 Ma and correlate closely with the Devonian–Carboniferous magmatism of Marie Byrd Land and New Zealand. Triassic (240–220 Ma) magmatism is identified at two sites on Thurston Island, with Hf isotopes indicating magma extraction from Mesoproterozoic-age lower crust. Several sites on Thurston Island preserve rhyolitic tuffs that have been dated at 182 Ma and are likely to correlate with the successions in the Antarctic Peninsula, particularly given the pre-break-up position of the Thurston Island crustal block. Silicic volcanism was widespread in Patagonia and the Antarctic Peninsula at ~ 183 Ma forming the extensive Chon Aike Province. The most extensive episode of magmatism along the active margin took place during the mid-Cretaceous. This Cordillera ‘flare-up’ event of the Gondwana margin is also developed on Thurston Island with granitoid magmatism dated in the interval 110–100 Ma.

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Di Bella, Marcella, Selma Russo, Maurizio Petrelli, and Angelo Peccerillo. "Origin and evolution of the Pleistocene magmatism of Linosa Island (Sicily Channel, Italy)." European Journal of Mineralogy 20, no. 4 (August 29, 2008): 587–601. http://dx.doi.org/10.1127/0935-1221/2008/0020-1832.

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Kos'ko, M., and E. Korago. "Review of geology of the New Siberian Islands between the Laptev and the East Siberian Seas, North East Russia." Stephan Mueller Special Publication Series 4 (September 17, 2009): 45–64. http://dx.doi.org/10.5194/smsps-4-45-2009.

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Abstract. The New Siberian Islands comprise De Long Islands, Anjou Islands, and Lyakhov Islands. Early Paleozoic, Mesozoic and Cenozoic sediments and igneous rocks are known on the De Long Islands. Cambrian slate, siltstone, mudstone and silicified limestone occur on Bennett Island. Ordovician volcanogenic turbidites, lavas, and small intrusions of andesite-basalt, basalt, dolerite, and porphyritic diorite were mapped on Henrietta Island. The igneous rocks are of calc-alkaline island arc series. The Ordovician age of the sequence was defined radiometrically. Early Paleozoic strata were faulted and folded presumably in the Caledonian time. Early Cretaceous sandstone and mudstone are known on Bennett Island. They are overlain by a 106–124 Ma basalt unit. Cenozoic volcanics are widespread on the De Long Islands. Zhokhov Island is an eroded stratovolcano. The volcanics are mostly of picrite-olivine type and limburgite. Radiometric dating indicates Miocene to Recent ages for Cenozoic volcanism. On the Anjou islands Lower-Middle Paleozoic strata consist of carbonates, siliciclastics, and clay. A Northwest-southeast syn-sedimentary facies zonation has been reconstructed. Upper Paleozoic strata are marine carbonate, clay and siliciclastic facies. Mudstone and clay predominate in the Triassic to Upper Jurassic section. Aptian-Albian coal bearing deposits uconformably overlap lower strata indicating Early Cretaceous tectonism. Upper Cretaceous units are mostly clay and siltstone with brown coal strata resting on Early Cretaceous weathered rhyolite. Cenozoic marine and nonmarine silisiclastics and clay rest upon the older units with a transgressive unconformity including a weathering profile in the older rocks. Manifestations of Paleozoic and Triassic mafic and Cretaceous acidic magmatism are also found on these islands. The pre-Cretaceous structure of the Anjou islands is of a block and fold type Late Cimmerian in age followed by faulting in Cenozoic time. The Lyakhov islands are located at the western end of the Late Cimmerian South Anyui suture. Sequences of variable age, composition, and structural styles are known on the Lyakhov Islands. These include an ancient metamorphic sequence, Late Paleozoic ophiolitic sequence, Late Mesozoic turbidite sequence, Cretaceous granites, and Cenozoic sediments. Fold and thrust imbricate structures have been mapped on southern Bol'shoi Lyakhov Island. North-northwestern vergent thrusts transect the Island and project offshore. Open folds of Jurassic–Early Cretaceous strata are characteristic of Stolbovoi and Malyi Lyakhov islands. Geology of the New Siberian Islands supports the concept of a circum Arctic Phanerozoic fold belt. The belt is comprised of Caledonian, Ellesmerian, Early Cimmerian and Late Cimmerian fold systems, manifested in many places on the mainland and on islands around the Arctic Ocean. Knowledge of the geology of the New Siberian Islands has been used to interpret anomalous gravity and magnetic field maps and Multi Channel Seismic (MCS) lines. Two distinguishing structural stages are universally recognized within the offshore sedimentary cover which correlate with the onshore geology of the New Siberian Islands. Dating of the upper structural stage and constituent seismic units is based on structural and stratigraphic relationships between Late Mesozoic and Cenozoic units in the archipelago. The Laptev Sea–western East Siberian Sea seismostratigraphic model for the upper structural stage has much in common with the seismostratigraphic model in the American Chukchi Sea.

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Birkenmajer, K., L. Francalanci, and A. Peccerillo. "Petrological and geochemical constraints on the genesis of Mesozoic–Cenozoic magmatism of King George Island, South Shetland Islands, Antarctica." Antarctic Science 3, no. 3 (September 1991): 293–308. http://dx.doi.org/10.1017/s0954102091000354.

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Petrological and geochemical data are reported for a series of Late Cretaceous-Middle Miocene volcanic, hypabyssal and intrusive rocks from King George Island (KGI) and from nearby Ridley Island, South Shetland Islands. Major element data indicate a calc-alkaline, basic to intermediate composition for the analysed samples. Although emplaced on a continental margin, the KGI rocks generally display low abundances of incompatible trace elements, close to those typically observed in calc-alkaline suites erupted in intraoceanic island arcs. A few samples have a significant negative Ce anomaly. Many incompatible elements define smooth positive trends on interelemental variation diagrams which suggests that magmas erupted at different times on KGI maintained a rather constant composition in terms of incompatible element ratios. Geochemical modelling, based on Sr isotope ratios and incompatible element ratios, suggests that the primary calc-alkaline magmas of KGI were all generated in an upper mantle modified by addition of small amounts of pelagic sediments dragged down by subduction processes.

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Volodkova, T. V. "Magmatism of Kunashir island (Kuril island arc) from aerogeophysical evidence." Russian Journal of Pacific Geology 1, no. 6 (December 2007): 515–36. http://dx.doi.org/10.1134/s1819714007060024.

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9

Sushchevskaya, N. M., A. N. Evdokimov, B. V. Belyatsky, V. A. Maslov, and D. V. Kuz’min. "Conditions of Quaternary magmatism at Spitsbergen Island." Geochemistry International 46, no. 1 (January 2008): 1–16. http://dx.doi.org/10.1134/s0016702908010011.

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Sushchevskaya, N. M., E. A. Korago, B. V. Belyatsky, and A. N. Sirotkin. "Geochemistry of Neogene magmatism at Spitsbergen Island." Geochemistry International 47, no. 10 (October 2009): 966–78. http://dx.doi.org/10.1134/s0016702909100024.

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11

Turner, Simon. "Scientists share knowledge about island arc magmatism." Eos, Transactions American Geophysical Union 78, no. 32 (1997): 333. http://dx.doi.org/10.1029/97eo00219.

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12

Connelly, James N., and A. Bruce Ryan. "Age and tectonic implications of Paleoproterozoic granitoid intrusions within the Nain Province near Nain, Labrador." Canadian Journal of Earth Sciences 36, no. 5 (May 1, 1999): 833–53. http://dx.doi.org/10.1139/e99-002.

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U-Pb (zircon) age determinations from three granitoid intrusions in the Nain region, formerly assigned to the well-known 1.35-1.29 Ga (Mesoproterozoic) Nain Plutonic Suite (NPS), indicate that they were emplaced, instead, during the Paleoproterozoic. Crystallization ages of 2109 ± 3 Ma for Sheet Hill granite, 2052 ± 4 Ma for Loon Island granite, and 2025 ± 7 Ma for Satok Island monzonite demonstrate a decreasing time of emplacement from north to south. Leucocratic basic rocks, superficially similar to those of the NPS, occur as inclusions within the Satok Island monzonite and are intruded by an 1873 ± 4 Ma granitic aplite dyke north of Webb's Bay. The ages clearly demonstrate granitic magmatism in the Nain area for at least 750 Ma, and anorthositic magmatism for at least 675 Ma, before the development of NPS. The earliest Paleoproterozoic magmatism (2109-2025 Ma) may have coincided with breakup of the North Atlantic craton, whereas the local magmatism represented by the 1873 Ma aplite dyke may be related to the embryonic stages of the continental collision that produced the 1860-1740 Ma Torngat Orogen. Leucocratic basic rocks associated with the Paleoproterozoic granitic rocks identified here could be Archean in age, but are more likely coeval with the granites. Other granitic and basic rocks in the Nain area may likewise be products of this bimodal plutonism. Identification of this possible geological duality suggests repetitive magmatism of "anorogenic type" over a significant time span in this part of Labrador. If the mantle-plume-related genesis accorded the Mesoproterozoic NPS is applicable to the Paleoproterozoic rocks, it implies multiple periods of similar lithosphere-asthenosphere interaction in this area, beginning at least in the Paleoproterozoic. The Paleoproterozoic magmas may have been emplaced into Nain Province crust along a linear intracontinental extension zone inboard from a rifted margin.

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13

D'LEMOS, R. S., B. V. MILLER, and S. D. SAMSON. "Precise U–Pb zircon ages from Alderney, Channel Islands: growing evidence for discrete Neoproterozoic magmatic episodes in northern Cadomia." Geological Magazine 138, no. 6 (November 2001): 719–26. http://dx.doi.org/10.1017/s0016756801005921.

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The northernmost exposures of rocks formed during the Late Neoproterozoic Cadomian orogeny in the Channel Islands–northern France region occur on Alderney. The island mainly comprises foliated quartz diorite, once considered to be 2 Ga, pre-Cadomian basement, and an undeformed basic to intermediate plutonic complex. A precise age of 610±2 Ma, based on U–Pb analyses of single and small groups of zircons, for the foliated Fort Tourgis quartz diorite demonstrates that the oldest rocks were emplaced and deformed during a Cadomian magmatic event. The age is virtually identical to ages from similar, foliated syntectonic quartz diorite bodies on the islands of Guernsey and Sark and at La Hague (north Normandy), indicating that this magmatic and deformational event was regional in extent. Discordant zircon xenocrysts define an upper intercept age of c. 2 Ga indicating the presence of Palaeoproterozoic basement at depth. Single zircons from the undeformed Bibette Head granodiorite give a precise U–Pb age of 572±1 Ma. This age is closely similar to that for the emplacement of the Northern Igneous Complex of Guernsey. The emerging data indicate that Cadomian magmatism in the northern Channel Islands region was not a protracted continuum, but occurred during two distinct, short-lived events separated by c. 30–40 my.

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Moon, Inkyeong, Hyunwoo Lee, Jonguk Kim, Jihye Oh, Donghoon Seoung, Chang Hwan Kim, Chan Hong Park, and Insung Lee. "Ti-Magnetite Crystallization in Melt Inclusions of Trachytic Rocks from the Dokdo and Ulleung Islands, South Korea: Implications for Hydrous and Oxidized Magmatism." Minerals 10, no. 7 (July 20, 2020): 644. http://dx.doi.org/10.3390/min10070644.

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The Dokdo and Ulleung islands (Korea) are volcanic islands in the East Sea (Sea of Japan), formed in the late Cenozoic. These volcanic islands, in the back-arc basin of the Japanese archipelago, provide important information about magma characteristics in the eastern margin of the Eurasian plate. The origin of the Dokdo and Ulleung intraplate volcanism is still controversial, and the role of fluids, especially water, in the magmatism is poorly understood. Here, we comprehensively analyzed the melt inclusions (10–100 m in diameter) hosted in clinopyroxene phenocrysts of trachyte, trachyandesite, and trachybasalt. In particular, we observed Ti-magnetite and amphibole which were crystallized as daughter mineral phases within melt inclusions, suggesting that Ti-magnetite was formed in an oxidized condition due to H2O dissociation and H2 diffusion. The Ti-magnetite exhibited compositional heterogeneities of MgO (average of 8.28 wt %), Al2O3 (average of 8.68 wt %), and TiO2 (average of 8.04 wt %). The positive correlation of TiO2 with Cr2O3 is probably attributed to evolutionary Fe–Ti-rich parent magma. Correspondingly, our results suggested hydrous and oxidized magmatism for the Dokdo and Ulleung volcanic islands.

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Zanon, Vittorio. "Chapter 5 The magmatism of the Azores islands." Geological Society, London, Memoirs 44, no. 1 (2015): 51–64. http://dx.doi.org/10.1144/m44.5.

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Davidson, J. P., and W. A. Bohrson. "Shallow-Level Processes in Ocean-island Magmatism: Editorial." Journal of Petrology 39, no. 5 (May 1, 1998): 799–801. http://dx.doi.org/10.1093/petroj/39.5.799.

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COOK, R. D., M. L. CRAWFORD, G. I. OMAR, and W. A. CRAWFORD. "Magmatism and deformation, southern Revillagigedo Island, southeastern Alaska." Geological Society of America Bulletin 103, no. 6 (June 1991): 829–41. http://dx.doi.org/10.1130/0016-7606(1991)103<0829:madsri>2.3.co;2.

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MCCARRON, JOE J., and IAN L. MILLAR. "The age and stratigraphy of fore-arc magmatism on Alexander Island, Antarctica." Geological Magazine 134, no. 4 (July 1997): 507–22. http://dx.doi.org/10.1017/s0016756897007437.

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Fore-arc magmatic sequences associated with high Mg number andesite lavas unconformably overlie LeMay Group accretionary complex in Alexander Island. High-resolution 40Ar/39Ar, U–Pb zircon, fission track and K–Ar ages demonstrate that subduction-related fore-arc magmatism migrated northwards along the length of Alexander Island between c. 80 Ma and c. 46 Ma. The magmatic rocks represent a third of the western margin of the Antarctic Peninsula magmatic arc and are critical to the understanding of the final phase of subduction along the southern Antarctic Peninsula margin. The onset of late Cretaceous magmatism is recorded by poorly exposed volcanic rocks on Monteverdi Peninsula (79.7±2.5 Ma). In central and northern Alexander Island, the magmatic rocks can be distinguished by the proportion, range and types of lithofacies present, and by the periods of magmatism represented. The volcanic rocks of the Colbert Mountains range in age from c. 69–62 Ma and are dominated by large volume dacitic and rhyolitic crystal-rich ignimbrites interpreted as caldera-fill deposits. Elgar Uplands sequences range in age from c. 55–50 Ma, and contain approximately equal proportions of pyroclastic deposits and less evolved (basaltic-andesite and andesite) lavas including high Mg number andesite lavas near the base of three sequences. The volcanic rocks of Finlandia Foothills probably represent the youngest calc-alkaline units on Alexander Island (48±2 Ma). The sequence is lithologically similar to the Elgar Uplands and also contains high Mg number andesite lavas, but it is dominated by polymict conglomerates, with minor lavas, which were deposited in a graben associated with regional extension. Plutonic rocks exposed in the Rouen Mountains, adjacent to the Elgar Uplands, yielded a U–Pb age of 56±3 Ma which is in discordance with a previously published Rb–Sr age (46±3 Ma), probably due to hydrothermal perturbation of the Rb–Sr system. Northwards migration of magmatism was caused by the progressive collision and subduction of three ridge segments prior to the previously reported ridge crest–trench collisions that occurred c. 20–30 Ma later and following which subduction ceased.

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Takashima, Isao, and Dwi Fitri Yudiantoro. "Magmatism and Geothermal Potential in Pandan Volcano East Java Indonesia." Jurnal Mineral, Energi dan Lingkungan 2, no. 2 (February 11, 2019): 50. http://dx.doi.org/10.31315/jmel.v2i2.2214.

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Pandan volcano is a volcano formed on Tertiary sedimentary rocks from the Kendeng zone deposited in the basin of East Java. In addition to generating petroleum potentials, such as Cepu and Bojonegoro oil fields, this area also generates geothermal potential. As a source of heat from the geothermal system is igneous rock formed from the magmatism process. The type of rock formed by the process of magmatism in the Pandan geothermal system is basaltic-andesitic and hornblende andesite are medium-high K calk alkaline affinity located in the island arc. The interaction of hot rock from post magmatism process with hydrothermal fluid resulted in the manifestation of hot springs and calcite travertine in the study area. Prediction of the subsurface temperature of hot water from geothermometer silica analysis contained in Banyukuning and Jarikasinan show cristobalite Beta equilibrium (70oC) and quartz temperature (120oC). To study about magmatism and geothermal fluid using petrographic method and petrochemical analysis (X-ray fluorescence spectrometry method) to the sample of igneous rock. While to study the fluid type and geothermometer of geothermal fluid using data from previous researchers. This research study is expected to provide additional information on the field of geothermal and magmatism in this area.

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Hole, M. J., R. M. Ellam, D. I. M. Macdonald, and S. P. Kelley. "Gondwana break-up related magmatism in the Falkland Islands." Journal of the Geological Society 173, no. 1 (October 27, 2015): 108–26. http://dx.doi.org/10.1144/jgs2015-027.

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Macdonald, Ray. "Magmatism of the Kenya Rift Valley: a review." Transactions of the Royal Society of Edinburgh: Earth Sciences 93, no. 3 (September 2002): 239–53. http://dx.doi.org/10.1017/s0263593300000420.

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ABSTRACTTertiary–Recent magmatism in the Kenya Rift Valley was initiated c. 35 Ma, in the northern part of Kenya. Initiation of magmatism then migrated southwards, reaching northern Tanzania by 5–8 Ma. This progression was accompanied by a change in the nature of the lithosphere, from rocks of the Panafrican Mozambique mobile belt through reworked craton margin to rigid, Archaean craton. Magma volumes and the geochemistry of mafic volcanic rocks indicate that magmatism has resulted from the interaction with the lithosphere of melts and/or fluids from one or more mantle plumes. Whilst the plume(s) may have been characterised by an ocean island basalt-type component, the chemical signature of this component has everywhere been heavily overprinted by heterogeneous lithospheric mantle. Primary mafic melts have fractionated over a wide range of crustal pressures to generate suites resulting in trachytic (silica-saturated and-undersaturated) and phonolitic residua. Various Neogene trachytic and phonolitic flood sequences may alternatively have resulted from volatile-induced partial melting of underplated mafic rocks. High-level partial melting has generated peralkaline rhyolites in the south–central rift. Kenyan magmatism may, at some future stage, show an increasing plume signature, perhaps associated ultimately with continental break-up.

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AWAD, Hamdy Ahmed Mohamed, and Aleksey Valer`evich NASTAVKIN. "Geological and petrographical studies around Um Taghir area, Сentral Eastern Desert, Egypt." NEWS of the Ural State Mining University 1, no. 1 (March 23, 2020): 7–25. http://dx.doi.org/10.21440/2307-2091-2020-1-7-25.

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Um Taghir area is located in the northern extreme boundary of Central Eastern Desert of Egypt at the west of Safaga City. Um Taghir is represented by island arc related rocks and late to post tectonic magmatism. The island arc related rocks are represented by metavolcaniclastic sequences and metagabrroic rocks. Metavolcanoclastic rocks are considered as the older rock units of the study are and intruded by the metagabbro. The late to post tectonic magmatism is represented by (dokhan volcanic, gabbro, tonalite-granodiorite, monzogranite, alkali feldspar granites and different types of dikes). Usually, the gabbroic rock is bearing ilmenite lenses or bands in the bottom of the layered; this is related to magma rich of iron oxides. Petrographically, island arc assemblage is classified in to actinolite hornblende schist and metagabbro that show quite different of their content in plagioclase, hornblende, augite, quartz and biotite. Occasionally, the late to post tectonic magmatism represented by andesite, gabbro, tonalite, granodiorite monzogranite, alkali feldspar granites and different types of dikes. Andesite consists of plagioclase, quartz, alkali feldspar and hornblende. Gabbroic rocks are represented by pyroxene hornblende gabbro and leucogabbro. They show quite different of their content in plagioclase, pyroxene and clear difference in the content of both olivine and hornblende in both of them. While tonalite and granodiorite show quite different of their content in plagioclase, quartz, hornblende, alkali felspar and biotite. On the other hand, monzogranite and alkali feldspar granite, they show plagioclase is varying from oligoclase to albite; K-feldspars, quartz and muscovite are relatively more abundant in the alkali feldspar granite. Finally, the different types of dikes classified into granite, andesite, rhyolite and basalt dikes consist of the different mineral compositions.

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Longpré, Marc-Antoine, Valentin R. Troll, Thomas R. Walter, and Thor H. Hansteen. "Volcanic and geochemical evolution of the Teno massif, Tenerife, Canary Islands: Some repercussions of giant landslides on ocean island magmatism." Geochemistry, Geophysics, Geosystems 10, no. 12 (December 2009): n/a. http://dx.doi.org/10.1029/2009gc002892.

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Khomich, Vadim G., Natalia G. Boriskina, and Sergei A. Kasatkin. "Geology, magmatism, metallogeny, and geodynamics of the South Kuril islands." Ore Geology Reviews 105 (February 2019): 151–62. http://dx.doi.org/10.1016/j.oregeorev.2018.12.015.

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Hasegawa, Akira, Junichi Nakajima, Takahiro Yanada, Naoki Uchida, Tomomi Okada, Dapeng Zhao, Toru Matsuzawa, and Norihito Umino. "Complex slab structure and arc magmatism beneath the Japanese Islands." Journal of Asian Earth Sciences 78 (December 2013): 277–90. http://dx.doi.org/10.1016/j.jseaes.2012.12.031.

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Kusakabe, Minoru, Keisuke Nagao, Takeshi Ohba, Jung Hun Seo, Sung-Hyun Park, Jong Ik Lee, and Byong-Kwon Park. "Noble gas and stable isotope geochemistry of thermal fluids from Deception Island, Antarctica." Antarctic Science 21, no. 3 (February 11, 2009): 255–67. http://dx.doi.org/10.1017/s0954102009001783.

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AbstractNew stable isotope and noble gas data obtained from fumarolic and bubbling gases and hot spring waters sampled from Deception Island, Antarctica, were analysed to constrain the geochemical features of the island's active hydrothermal system and magmatism in the Bransfield back-arc basin. The 3He/4He ratios of the gases (< 9.8 × 10-6), which are slightly lower than typical MORB values, suggest that the Deception Island magma was generated in the mantle wedge of a MORB-type source but the signature was influenced by the addition of radiogenic 4He derived from subducted components in the former Phoenix Plate. The N2/He ratios of fumarolic gas are higher than those of typical mantle-derived gases suggesting that N2 was added during decomposition of sediments in the subducting slab. The δ13C values of -5 to -6‰ for CO2 also indicate degassing from a MORB-type mantle source. The H2/Ar- and SiO2 geothermometers indicate that the temperatures in the hydrothermal system below Deception Island range from ~150°C to ~300°C. The δD and δ18O values measured from fumarolic gas and hot spring waters do not indicate any contribution of magmatic water to the samples. The major ionic components and δD-δ18O-δ34S values indicate that hot spring waters are a mixture of local meteoric water and seawater. Mn and SiO2 in spring waters were enriched relative to seawater reflecting water-rock interaction at depth.

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Trettin, H. P., and R. Parrish. "Late Cretaceous bimodal magmatism,northern Ellesmere Island:isotopic age and origin." Canadian Journal of Earth Sciences 24, no. 2 (February 1, 1987): 257–65. http://dx.doi.org/10.1139/e87-027.

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In the Yelverton Bay region of northwestern Ellesmere Island, bimodal intrusive and volcanic rocks are associated with a major fault in the Proterozoic–Cambrian rocks of the Pearya Terrane. The Wootton intrusion consists mainly of gabbro with lesser amounts of granitic and hybrid rocks; the Hansen Point volcanics are composed of felsic rocks and basalt. Plutonic zircons are very slightly discordant, but volcanic zircons have unusually high degrees of inheritance. Interpreted U/Pb zircon ages of 92.0 ± 1.0 Ma for the Wootton intrusion (assuming a wide range of inheritance ages) and of [Formula: see text] for the Hansen Point volcanics are close to the 93 Ma average of hornblende K/Ar dates obtained earlier for a small quartz diorite pluton in central northernmost Ellesmere Island. All fall into the early Late Cretaceous and indicate correlation with mafic volcanics of the Cenomanian–Turonian Strand Fiord Formation of eastern Axel Heiberg Island. The upper intercept age for the Hansen Point volcanics ([Formula: see text]) suggests that the felsic component in the bimodal suites was in part derived from the upper Middle Proterozoic (Neohelikian) basement gneiss. Limited field observations on the Wootton intrusion also are compatible with the hypothesis that the granitic component represents sialic basement, melted by mafic intrusion at depth during an extensional tectonic regime.

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28

Puchkov, Viktor N. "The plume-dependent granite-rhyolite magmatism." LITOSFERA, no. 5 (October 28, 2018): 692–705. http://dx.doi.org/10.24930/1681-9004-2018-18-5-692-705.

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The plume-dependent magmatism is widespread and well justified. The bulk of it is represented by flood basalts, basalts of oceanic islands (OIB), and basalts of oceanic plateaus (OPB), though the whole scope of plume magmatism is very diverse. A noticeable role among them is played also by acid (silicic) magmatic rocks - rhyolites and granites. Two main types of plume magmatism are recognized. The first belongs to Large Igneous Provinces (LIP) and is thought to be born at the Core-Mantle boundary within structures, called superswells, that produce giant, short-living mantle upwellings, resulting in abundant volcanism on the Earth’s surface. The second type is represented by linear volcanic chains characterized by regular age progressions. They are formed by single plumes - thin ascending mantle flows, acting during longer periods of time. It is shown that the abundance of silicic magmatism strongly depends on the type of the earth’s crust. Among flood basalts of continents, silicic magmatism is usually present, subordinate in volume to basalts and belongs to a bimodal type of magmatism. But in some cases LIP in continents are formed predominantly by silicic rocks; they are given the name Silicic LIPS, or SLIPS. In oceans, LIP are fundamentally basaltic with no considerable volume of silicic volcanics, if any. The time-progressive volcanic chains in continents are rare and usually comprise a noticeable silicic component. In oceans, the chains are composed mostly of basalts (OIB type), though in the top parts of volcanoes more acid and alkaline differentiates are present; usually they lack rhyolites and granites, except the cases of a presence of some strips of continental crust or anomalously thick oceanic crust. This review can lead to a thought of an important role of melting of continental crust in formation of plume-dependent rhyolite-granite magmatism. As for the Urals, the proofs for a presence of plume-dependent magmatism in its history were presented only recently. Among the plume episodes, some are characterized by presence of silicic components, in particular: Mashak (1380-1385 Ma), Igonino (707-732 Ma), Man’khambo (mainly Cambrian), Ordovician Kidryasovo, Stepninsky (Permian) and Urals-Siberian (Triassic).

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29

Turner, S. P. "On the time–scales of magmatism at island–arc volcanoes." Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences 360, no. 1801 (October 24, 2002): 2853–71. http://dx.doi.org/10.1098/rsta.2002.1060.

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30

BRIGGS, R. M., and W. F. MCDONOUGH. "Contemporaneous Convergent Margin and Intraplate Magmatism, North Island, New Zealand." Journal of Petrology 31, no. 4 (August 1, 1990): 813–51. http://dx.doi.org/10.1093/petrology/31.4.813.

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31

Dovzhikova, Elena, Victoria Pease, and Dimitry Remizov. "Neoproterozoic island are magmatism beneath the Pechora Basin, NW Russia." GFF 126, no. 4 (December 1, 2004): 353–62. http://dx.doi.org/10.1080/11035890401264353.

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32

d'Lemos, R. S., and M. Brown. "Sm–Nd isotope characteristics of late Cadomian granite magmatism in northern France and the Channel Islands." Geological Magazine 130, no. 6 (November 1993): 797–804. http://dx.doi.org/10.1017/s0016756800023165.

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AbstractSm–Nd isotopic studies of granites within the late Precambrian, Cadomian, orogenic belt of the North Armorican Massif (northwestern France) and Channel Islands reveal differences between arc-related granite magmatism in outboard terranes and intracrustal granite magmatism in inboard terranes. Late Cadomian (c. 570 Ma), arc-related granitoids exhibit a range of εnd( - 2 to - 6) and Nd model ages (TDM1.0–1.3 Ga) reflecting variable contamination between late Precambrian mantle derived magmas and ancient (c. 2.0 Ga?) continental crust. The contamination did not involve exposed granitic Icartian basement to anygreat degree, a more likely contaminant being unexposed lower crust of intermediate to acidic granulitic composition, or early Cadomian plutons which were themselves contaminated by lower crust. Voluminous granites of the Mancellian region (c. 550–540 Ma) share common isotopic characteristics (εNd-4 to -7, TDM1.5–1.7 Ga) with migmatites and anatectic granites produced by partial melting of metasedimentary sequences within the St Malo region consistent with a common source.

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33

Udoratina, O. V., K. V. Kulikova, A. S. Shuyskiy, A. A. Sobolevа, V. L. Andreichev, I. I. Golubeva, and V. A. Kapitanova. "GRANITOID MAGMATISM IN THE NORTH OF THE URALS: U–Pb AGE, EVOLUTION, SOURCES." Geodynamics & Tectonophysics 12, no. 2 (June 23, 2021): 287–309. http://dx.doi.org/10.5800/gt-2021-12-2-0525.

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This work presents the summarization of U–Pb (SIMS, TIMS) zircon dates and petrogeochemical signatures of granitoids of the north of the Urals (Polar, Subpolar, and Northern Urals) obtained over the last decade. Granitе melts were formed from melting of different substrates, highly heterogeneous in composition and age, at all geodynamic stages distinguished in the studied area. Preuralides include island arc–accretionary (735–720 Ma, 670 Ma), collisional (650–520 Ma), and rift-related (520–480 Ma) granitoids. Uralides includes primitive island-arc granitoids (460–429 Ma), mature island-arc granitoids (412–368 Ma), early collisional (360–316 Ma) and late collisional (277–249 Ma) granitoids. As a result, the general trend of variations of oxygen (δ18OZrn, ‰), neodymium (εNd(t)wr), and hafnium (εHf(t)Zrn) isotope compositions identified in time. Mantle isotope compositions (δ18OZrn (+5.6), εNd(t)wr (+1.7), εHf(t)Zrn (+8.7...+10.6)), common for island arc granitoids (Preuralides) are changed by crustal–mantle ones (δ18OZrn (+7.2...+8.5), εNd(t)wr (–4.8...+1.8), εHf(t)Zrn (+2.1 to +13)), typical of collisional granites. According to this, the crustal matter played a significant role during the formation of the latter. The crustal-mantle isotope compositions are changed by the mantle ones, characteristic of rift-related (δ18OZrn (+4.7...+7), εNd(t)wr (+0.7...+5.6), εHf(t)Zrn (–2.04...+12.5)) and island-arc (Uralides; δ18OZrn (+4.2...+5.7), εNd(t)wr (+4.1...+7.4), εHf(t)Zrn (+12...+15.2)) granitoids.

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34

Reginiussen, H., E. J. Krogh Ravna, and K. Berglund. "Mafic dykes from Øksfjord, Seiland Igneous Province, northern Norway: geochemistry and palaeotectonic significance." Geological Magazine 132, no. 6 (November 1995): 667–81. http://dx.doi.org/10.1017/s0016756800018902.

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AbstractMafic dykes from the Øksfjord-Langfjord area were intruded at different stages during the prolonged tectonomagmatic evolution of the Seiland Igneous Province. Field relations, petrography and geochemistry indicate the presence of four dyke generations with alkali basalt composition and one generation of alkaline lamprophyres. The entire dyke suite has geochemical signatures consistent with formation in a within-plate geotectonic environment. Trace elements indicate that the alkali basalt dykes have OIB (ocean island basalt) affinities and we suggest a sublithospheric mantle source. The data support a rift-related origin for the Seiland Igneous Province. Longevity of magmatism in the Seiland Igneous Province (300 m.y.) is difficult to explain within a conventional mantle plume framework. Instead, it is proposed that the intermittent magmatism in the province was predominantly permissive and controlled by lithosphere structure.

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35

Baldwin, D. A., E. C. Syme, H. V. Zwanzig, T. M. Gordon, P. A. Hunt, and R. D. Stevens. "U–Pb zircon ages from the Lynn Lake and Rusty Lake metavolcanic belts, Manitoba: two ages of Proterozoic magmatism." Canadian Journal of Earth Sciences 24, no. 5 (May 1, 1987): 1053–63. http://dx.doi.org/10.1139/e87-101.

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Two ages of magmatism have been determined from zircon in felsic flows and plutons in the Churchill Province of Manitoba. A rhyolite flow from the Lynn Lake metavolcanic belt has a U–Pb age of [Formula: see text], and a rhyolite flow from the adjacent Rusty Lake metavolcanic belt has an age of [Formula: see text]. Tonalite and quartz diorite from two composite plutons emplaced into the volcanic rocks at Lynn Lake have ages of [Formula: see text] and [Formula: see text], indistinguishable from the age of the Rusty Lake belt rhyolite. The arcuate domain of metavolcanic rocks that includes the Rusty Lake belt in the southeast, the Lynn Lake belt in the north, and the La Ronge belt (Saskatchewan) in the southwest has previously been considered a single structural sub-province with similar ages throughout. Our results and published U–Pb ages from Saskatchewan indicate that an older magmatism is represented by volcanic rocks in the Lynn Lake belt; a younger magmatism, by volcanic rocks in the Rusty Lake and La Ronge belts and plutons in the Lynn Lake belt. At Lynn Lake the older magmatism (1910 Ma) produced mafic, intermediate, and felsic volcanic rocks and synvolcanic plutons. The volcanic rocks are geochemically similar to Cenozoic island-arc magmatic sequences. These rocks were isoclinally folded and subsequently intruded by the 1876 Ma plutons. The younger, dominantly subaerial, volcanism (1878 Ma) at Rusty Lake was predominantly felsic, and the coeval plutons were granitoid. The distribution of ages and the 8 km thickness of the younger volcanic sequence suggest that the older rock served as basement during the younger magmatism.

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36

DINI, A., F. INNOCENTI, S. ROCCHI, S. TONARINI, and D. S. WESTERMAN. "The magmatic evolution of the late Miocene laccolith–pluton–dyke granitic complex of Elba Island, Italy." Geological Magazine 139, no. 3 (May 2002): 257–79. http://dx.doi.org/10.1017/s0016756802006556.

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Since late Miocene time, post-collisional extension of the internal parts of the Apennine orogenic belt has led to the opening of the Tyrrhenian basin. Extensive, mainly acidic peraluminous magmatism affected the Tuscan Archipelago and the Italian mainland during this time, building up the Tuscan Magmatic Province as the fold belt was progressively thinned, heated and intruded by mafic magmas. An intrusive complex was progressively built on western Elba Island by emplacement, within a stack of nappes, of multiple, shallow-level porphyritic laccoliths, a major pluton, and a final dyke swarm, all within the span from about 8 to 6.8 Ma. New geochemical and Sr–Nd isotopic investigations constrain the compositions of materials involved in the genesis of the magmas of Elba Island compared to the whole Tuscan Magmatic Province. Several distinct magma sources, in both the crust and mantle, have been identified as contributing to the Elba magmatism as it evolved from crust-, to hybrid-, to mantle-dominated. However, a restricted number of components, geochemically similar to mafic K-andesites of the Island of Capraia and crustal melts like the Cotoncello dyke at Elba, are sufficient to account for the generation by melt hybridization of the most voluminous magmas (c. εNd(t) −8.5, 87Sr/86Sr 0.715). Unusual magmas were emplaced at the beginning and end of the igneous activity, without contributing to the generation of these hybrid magmas. These are represented by early peraluminous melts of a different crustal origin (εNd(t) between −9.5 and −10.0, 87Sr/86Sr variable between 0.7115 and 0.7146), and late mantle-derived magma strongly enriched in incompatible elements (εNd(t) = −7.0, 87Sr/86Sr = 0.7114) with geochemical–isotopic characteristics intermediate between contemporaneous Capraia K-andesites and later lamproites from the Tuscan Magmatic Province. Magmas not involved in the generation of the main hybrid products are not volumetrically significant, but their occurrence emphasizes the highly variable nature of crust and mantle sources that can be activated in a short time span during post-collisional magmatism.

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37

Sasseville, C., K. Y. Tomlinson, A. Hynes, and V. McNicoll. "Stratigraphy, structure, and geochronology of the 3.02.7 Ga Wallace Lake greenstone belt, western Superior Province, southeast Manitoba, Canada." Canadian Journal of Earth Sciences 43, no. 7 (July 1, 2006): 929–45. http://dx.doi.org/10.1139/e06-041.

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In western Superior province, the North Caribou terrane (NCT) constitutes a Mesoarchean proto-continent heavily overprinted by Neoarchean magmatism and deformation resulting from the western Superior Province accretion. Locally, along the southern margin of the NCT, Mesoarchean (~3.0 Ga) rift sequences are preserved. These sequences are of key importance to our understanding of the early tectonic evolution of continental crust. The Wallace Lake greenstone belt is located at the southern margin of the NCT and includes the Wallace Lake assemblage, the Big Island assemblage, the Siderock Lake assemblage, and the French Man Bay assemblage. The Wallace Lake assemblage exposes one of the best-preserved Mesoarchean rift sequences along the southern margin of the NCT. The volcano-sedimentary assemblage (3.02.92 Ga) exposes arkoses derived from the uplift of a tonalite basement in a subaqueous environment, capped by carbonate and iron formation. Mafic to ultramafic volcanic rocks exhibiting crustal contamination and derived from plume magmatism cap this rift sequence. The Wallace Lake assemblage exhibits D1 Mesoarchean deformation. The Big Island assemblage comprises mafic volcanic rocks of oceanic affinity that were docked to the Wallace Lake assemblage along northwest-trending D2 shear zones. The timing of volcanism and docking of the Big Island assemblage remain uncertain. The Siderock Lake and French Man Bay assemblages were deposited in strike-slip basins related to D3 and D4 stages of movement of the transcurrent Wanipigow fault (<2.709 Ga). Regionally, the Wallace Lake assemblage correlates with the LewisStory Rift assemblage observed in Lake Winnipeg, whereas the Big Island assemblage appears to correlate with the Black Island assemblage observed in the Lake Winnipeg area. Thus, the North Caribou terrane appears to preserve vestiges of a Mesoarchean rifted succession together with overlying Neoarchean allochthonous, juvenile, volcanic successions over a considerable distance along its present-day southern margin.

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38

DRAUT, AMY E., PETER D. CLIFT, DAVID M. CHEW, MATTHEW J. COOPER, REX N. TAYLOR, and ROBYN E. HANNIGAN. "Laurentian crustal recycling in the Ordovician Grampian Orogeny: Nd isotopic evidence from western Ireland." Geological Magazine 141, no. 2 (March 2004): 195–207. http://dx.doi.org/10.1017/s001675680400891x.

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Because magmatism associated with subduction is thought to be the principal source for continental crust generation, assessing the relative contribution of pre-existing (subducted and assimilated) continental material to arc magmatism in accreted arcs is important to understanding the origin of continental crust. We present a detailed Nd isotopic stratigraphy for volcanic and volcaniclastic formations from the South Mayo Trough, an accreted oceanic arc exposed in the western Irish Caledonides. These units span an arc–continent collision event, the Grampian (Taconic) Orogeny, in which an intra-oceanic island arc was accreted onto the passive continental margin of Laurentia starting at ∼ 475 Ma (Arenig). The stratigraphy corresponding to pre-, syn- and post-collisional volcanism reveals a progression of εNd(t) from strongly positive values, consistent with melt derivation almost exclusively from oceanic mantle beneath the arc, to strongly negative values, indicating incorporation of continental material into the melt. Using εNd(t) values of meta-sediments that represent the Laurentian passive margin and accretionary prism, we are able to quantify the relative proportions of continent-derived melt at various stages of arc formation and accretion. Mass balance calculations show that mantle-derived magmatism contributes substantially to melt production during all stages of arc–continent collision, never accounting for less than 21% of the total. This implies that a significant addition of new, rather than recycled, continental crust can accompany arc–continent collision and continental arc magmatism.

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39

Kim, Cheolhong, Naing Aung Khant, Yongmun Jeon, Heejung Kim, and Chungwan Lim. "Geochemical Characterization of Intraplate Magmatism from Quaternary Alkaline Volcanic Rocks on Jeju Island, South Korea." Applied Sciences 11, no. 15 (July 30, 2021): 7030. http://dx.doi.org/10.3390/app11157030.

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The major and trace elements of Quaternary alkaline volcanic rocks on Jeju Island were analyzed to determine their origin and formation mechanism. The samples included tephrite, trachybasalts, basaltic trachyandesites, tephriphonolites, trachytes, and mantle xenoliths in the host basalt. Although the samples exhibited diversity in SiO2 contents, the relations of Zr vs. Nb and La vs. Nb indicated that the rocks were formed from the fractional crystallization of a single parent magma with slight continental crustal contamination (r: 0–0.3 by AFC modeling), rather than by the mixing of different magma sources. The volcanic rocks had an enriched-mantle-2-like ocean island basalt signature and the basalt was formed by partial melting of the upper mantle, represented by the xenolith samples of our study. The upper mantle of Jeju was affected by arc magmatism, associated with the subduction of the Pacific Plate beneath the Eurasian Plate. Therefore, we inferred that two separate magmatic events occurred on Jeju Island: one associated with the subduction of the Pacific Plate beneath the Eurasian Plate (represented by xenoliths), and another associated with a divergent setting when intraplate magmatism occurred (represented by the host rocks). With AFC modeling, it can be proposed that the Jeju volcanic rocks were formed by the fractional crystallization of the upper mantle combined with assimilation of the continental crust. The xenoliths in this study had different geochemical patterns from previously reported xenoliths, warranting further investigations.

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40

Nicholson, K. N., P. M. Black, and K. B. Sporli. "Cretaceous‐oligocene multiphase magmatism on three kings islands, northern New Zealand." New Zealand Journal of Geology and Geophysics 51, no. 3 (September 2008): 219–29. http://dx.doi.org/10.1080/00288300809509861.

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41

Leat, Philip T., Bryan C. Storey, and Robert J. Pankhurst. "Geochemistry of Palaeozoic–Mesozoic Pacific rim orogenic magmatism, Thurston Island area, West Antarctica." Antarctic Science 5, no. 3 (September 1993): 281–96. http://dx.doi.org/10.1017/s0954102093000380.

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Thurston Island, and the adjacent Eights Coast and Jones Mountains, record Pacific margin magmatism from Carboniferous to Late Cretaceous times. The igneous rocks form a uniformly calc-alkaline, high-alumina, dominantly metaluminous suite; some relatively fractionated granitoids are mildly peraluminous. The magmas were hydrous, a result of subduction. Gabbros have compositions outside the range of mafic volcanic and hypabyssal rocks, as a result of cumulate processes. Trace element compositions of the mafic magmas range from a low La/Yb, Th/Ta end-member close to E-MORB in composition, perhaps contaminated by crust, to a high La/Yb, Th/Ta end-member, close to shoshonite, with strong magmatic arc trace element character. This variation may be a result of mixing of tholeiitic and shoshonitic end-members. Most silicic rocks could have been generated batch-wise from mafic magmas by fractional crystallization of a phenocryst assemblage dominated by plagioclase, pyroxene ± amphibole, as seen in the cumulates. Cessation of magmatism at about 90 Ma approximately coincided with collison of a spreading centre between the Phoenix and Pacific oceanic plates with the continent margin subduction zone. The rifting of New Zealand from West Antarctica and associated extension probably was responsible for emplacement of a coast-parallel Cretaceous dyke swarm.

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42

Artemenko, G. V., and V. I. Ganotskiy. "Geochemical features of dike rocks of the Argentine islands and the near area of the antarctic peninsula (Western Antarctica)." Arctic and Antarctic Research 64, no. 3 (September 30, 2018): 270–93. http://dx.doi.org/10.30758/0555-2648-2018-64-3-270-293.

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The block of the Antarctic Peninsula is part of a magmatic arc formed along the southwestern part of the paleo-Pacific margin of the Gondwana supercontinent. Currently, subduction processes continue only in its northwestern part — in the region of the South Shetland islands, and to the southwest of it — there is a passive segment of the continental margin, within which the Argentine islands are located. Here, subduction was completed in the late Miocene-Early Pliocene. In the geological structure of the Argentine islands archipelago, the rocks of the Upper Jurassic volcanic group (AP Volcanic Group) and intrusive batholiths of the batholiths (AP batholiths) are distinguished. In them, there are numerous dikes of basic, medium and acidic compositions. The activation of dyke magmatism on the passive margin of the Antarctic Peninsula was probably connected with subduction processes in its northwestern part.The age sequence of dike formation in the rocks of the Antarctic Peninsula (AP) volcanic Group and intrusions of the gabbroids and granitoids of the Andean complex in the Argentine Islands and the near area of the Antarctic Peninsula is determined. The early dikes of the dacites in the volcanogenic stratum of the AP volcanic Group and the gabbrodiabases in the gabbroids of the Andean complex have a submeridional and northwestern strike. After the introduction of the granitoids of the Andean complex, dikes predominantly of the sublatitudinal and northeasterly strike are formed. The early dikes in the gabbroids of the Andean complex are Fe-Ti cumulates, and in granodiorite intrusions they are represented by aplites, probably formed from the residual magma of these intrusions. Later dikes were formed, probably due to the melting of the metasomatized mantle source at moderate depths under the influence of plumes. To their primitive (initial) melts, the composition of high-magnesian dike rocks is probably close. Products of deep mantle (plume) sources in the sample of selected samples were not detected. The dike rocks of this region according to their geochemical characteristics correspond to the mature island-arc formations of the calc-alkaline series.

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43

Makrygina, V. A. "Specifics of the Caledonian Collision in the Ol’khon Region (Lake Baikal, Russia)." Russian Geology and Geophysics 62, no. 4 (April 1, 2021): 389–400. http://dx.doi.org/10.2113/rgg20194122.

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Abstract —Analysis of geochemical, geochronological, and new geophysical data on metasedimentary and igneous rocks of the Ol’khon region has made it possible to substantiate: (1) the absence of products of the Caledonian suprasubduction magmatism from the adjacent part of the Siberian craton and (2) the presence of a product of this magmatism in the Anga–Talanchan island arc, namely, the Krestovsky massif with gabbro-diorite to granite phases. This suggests subduction of the Paleoasian oceanic crust under the island arc before the collision. The geophysical data showed a steep sinking of the Siberian craton margin. This sinking and the supposed contrary movement and rotation of the Siberian craton prevented the appearance of a subduction zone beneath the craton during the collision but caused the wide development of fault plates in the fold belt at the late collision stage. The residue of oceanic crust slab was pressed out along the fault planes near the surface and formed a row of gabbro-pyroxenite massifs of the Birkhin Complex in the fold belt, where syncollisional granitic melts (Sharanur Complex) formed at the same time. The interaction of two contrasting melts gave rise to the Tazheran and Budun alkaline syenite massifs and alkaline metasomatites of the Birkhin and Ulanganta gabbroid massifs.

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Tsvetkov, A. A. "Magmatism of the westernmost (Komandorsky) segment of the Aleutian Island Arc." Tectonophysics 199, no. 2-4 (December 1991): 289–317. http://dx.doi.org/10.1016/0040-1951(91)90176-s.

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45

Petrov, G. A., N. I. Tristan, G. N. Borozdina, and A. V. Maslov. "The final stage of the Acid Island Arc magmatism in the Northern Urals." Доклады Академии наук 489, no. 2 (November 20, 2019): 166–69. http://dx.doi.org/10.31857/s0869-56524892166-169.

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For the first time, the time of completion of the formation of calc-alkaline volcanic complexes of the Devonian Island Arc (Franian) in the Northern Urals was determined. It is shown that the late Devonian volcanic rocks of the Limka series have geochemical characteristics that bring them closer to the rocks of developed island arcs and active continental margins. The detected delay of the final episode of calc-alkaline volcanism in the Northern Urals in comparison with the similar event in the southern Urals may be due to the oblique nature of the subduction.

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Lindline, Jennifer, William A. Crawford, and Maria Luisa Crawford. "A bimodal volcanicplutonic system: the Zarembo Island extrusive suite and the Burnett Inlet intrusive complex." Canadian Journal of Earth Sciences 41, no. 4 (April 1, 2004): 355–75. http://dx.doi.org/10.1139/e04-009.

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The Zarembo Island volcanic rocks and the Burnett Inlet plutonic complex in central southeastern Alaska were investigated to determine if they are genetically related. The Zarembo Island volcanic suite consists of basalt, andesite, and rhyolite lava flows, which exhibit features that suggest simultaneous eruptions of mafic and felsic lavas. Five kilometres to the southeast, the broadly layered Burnett Inlet plutonic complex consists of gabbrodiorite and granite plutons that also show characteristics of contemporaneous mafic and felsic magmatism. These bimodal volcanic and plutonic rocks are similar in age, ranging from 18.5 to 21.5 Ma. Both suites show a gap in silica concentration between 60 and 65 wt.% and have similar major, trace, and rare-earth element composition. Both suites also show igneous layering, either as interlayered basalt and rhyolite flows or as alternating gabbro and granite sheets. Additionally, both groups contain magma mingling and mixing textures, including mafic enclaves in felsic members and quartz xenocrysts rimmed by clinopyroxene in enclaves. These characteristics suggest that the Burnett Inlet intrusive complex and the Zarembo Island volcanic suite represent an eroded, shallow-level plutonic center and its eruptive cover. The style of volcanism and the bimodal nature of magmatism suggest that igneous activity occurred during crustal extension and thinning that accompanied strike-slip tectonic motion in southeastern Alaska during the Tertiary. The volcanicplutonic rock associations now exposed at the surface indicate that at least 7° of post-20 Ma crustal tilting has affected the region and can help to explain aberrant paleomagnetic poles in mid-Cretaceous intrusions of the Cordillera Coast belt.

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Percival, J. A., V. McNicoll, and A. H. Bailes. "Strike-slip juxtaposition of ca. 2.72 Ga juvenile arc and >2.98 Ga continent margin sequences and its implications for Archean terrane accretion, western Superior Province, Canada." Canadian Journal of Earth Sciences 43, no. 7 (July 1, 2006): 895–927. http://dx.doi.org/10.1139/e06-039.

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The North Caribou terrane of the western Superior Province attained continental thickness (~35 km) by 2997 Ma. It records a subsequent 300 million years history of continental fragmentation, arc magmatism, and terrane accretion. At Lake Winnipeg the ~2978 Ma Lewis–Storey quartzite–komatiite–iron formation assemblage marks Mesoarchean breakup. Unlike the relatively continuous 2980–2735 Ma stratigraphic record of the Red Lake and Birch–Uchi greenstone belts to the east, little of this interval is recorded at Lake Winnipeg. Rather, two belts of younger, juvenile rocks are tectonically juxtaposed: the Black Island assemblage of isotopically depleted, 2723 Ma basalt, and calc-alkaline andesite; and Rice Lake greenstone belt of basalt, calc-alkaline andesite, and dacite (2731–2729 Ma). Collectively these terranes represent a short-lived island-arc–back-arc system that docked with the southwestern North Caribou margin along a northwest-trending, dextral, transpressive, D1 suture. This zone is marked by the highly deformed coarse clastic Guano Island sequence (<2728 Ma) that contains detritus of North Caribou affinity and is interpreted as a strike-slip basin deposit. Younger clastic sequences, including the Hole River (<2708 Ma), San Antonio (<2705 Ma), and English River (<2704 Ma) assemblages, occur in east–west belts that may have been deposited during the terminal collision (D2, D3) between the North Caribou terrane and continental crust of the Winnipeg River terrane to the south. Several terrane docking events within a framework of north-dipping subduction and continental arc magmatism appear necessary to explain structural and stratigraphic relationships in the 2735–2700 Ma interval.

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48

Kosarev, A. M., A. G. Vladimirov, A. I. Khanchuk, D. N. Salikhov, V. B. Kholodnov, T. A. Osipova, G. A. Kallistov, I. B. Seravkin, I. R. Rakhimov, and G. T. Shafigullina. "DEVONIAN-CARBONIFEROUS MAGMATISM AND METALLOGENY IN THE SOUTH URAL ACCRETIONARY-COLLISIONAL SYSTEM." Geodynamics & Tectonophysics 12, no. 2 (June 23, 2021): 365–91. http://dx.doi.org/10.5800/gt-2021-12-2-0529.

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The oceanic stage in the history of the South Urals completed in the Ordovician – Early Silurian. The Ordovician through Devonian events in the region included the formation of an island arc in the East Ural zone from the Middle Ordovician to Silurian; westward motion of the subduction zone in the Late Silurian – Early Devonian and the origin of a trench along the Main Ural Fault and the Uraltau Uplift; volcanic eruptions and intrusions in the Magnitogorsk island arc system in the Devonian. The Middle-Late Paleozoic geodynamic evolution of uralides and altaides consisted in successive alternation of subduction and collisional settings at the continent-ocean transition. The greatest portion of volcanism in the major Magnitogorsk zone was associated with subduction and correlated in age and patterns of massive sulfide mineralization (VMS) with Early – Middle Devonian ore-forming events in Rudny Altai. Within-plate volcanism at the onset of volcanic cycles records the Early (D1e2) and Middle (D2ef2) Devonian slab break off. The volcanic cycles produced, respectively, the Buribay and Upper Tanalyk complexes with VMS mineralization in the Late Emsian; the Karamalytash complex and its age equivalents in the Late Eifelian – Early Givetian, as well as the lower Ulutau Formation in the Givetian. Slab break off in the Late Devonian – Early Carboniferous obstructed the Magnitogorsk island arc and supported asthenospheric diapirism. A new subduction zone dipping westward and the Aleksandrovka island arc formed in the Late Devonian – Early Carboniferous. The Early Carboniferous collision and another event of obstructed subduction led to a transform margin setting corresponding to postcollisional relative sliding of plates that produced another slab tear. Postcollisional magmatism appears as alkaline gabbro-granitic intrusives with related rich Ti-magnetite mineralization (C1). Transform faulting persisted in the Middle Carboniferous through Permian, when the continent of Eurasia completed its consolidation. The respective metallogenic events included formation of Cu-Ni picritic dolerites (C2–3), as well as large-scale gold and Mo-W deposits in granites (P1–2).

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49

Kiseleva, Olga N., Evgeniya V. Airiyants, Dmitriy K. Belyanin, Sergey M. Zhmodik, Igor V. Ashchepkov, and Semyon A. Kovalev. "Multistage Magmatism in Ophiolites and Associated Metavolcanites of the Ulan-Sar’dag Mélange (East Sayan, Russia)." Minerals 10, no. 12 (November 30, 2020): 1077. http://dx.doi.org/10.3390/min10121077.

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We present new whole-rock major and trace element, mineral chemistry, and U-Pb isotope data for the Ulan-Sar’dag mélange, including different lithostratigraphic units: Ophiolitic, mafic rocks and metavolcanites. The Ulan-Sar’dag mélange comprises of a seafloor and island-arc system of remnants of the Paleo-Asian Ocean. Detailed studies on the magmatic rocks led to the discovery of a rock association that possesses differing geochemical signatures within the studied area. The Ulan-Sar’dag mélange includes blocks of mantle peridotite, podiform chromitite, cumulate rocks, deep-water siliceous chert, and metavolcanic rocks of the Ilchir suite. The ophiolitic unit shows overturned pseudostratigraphy. The nappe of mantle tectonites is thrusted over the volcanic-sedimentary sequence of the Ilchir suite. The metavolcanic series consist of basic, intermediate, and alkaline rocks. The mantle peridotite and cumulate rocks formed in a supra-subduction zone environment. The mafic and metavolcanic rocks belong to the following geochemical types: (1) Ensimatic island-arc boninites; (2) island-arc calc-alkaline andesitic basalts, andesites, and dacites; (3) tholeiitic basalts of mid-ocean ridges; and (4) oceanic island basalts. U–Pb dating of zircons from the trachyandesite, belonging to the second geochemical type, yielded a date of 833 ± 4 Ma which is interpreted as the crystallization age during mature island-arc and intra-arc rifting stages. The possible influence of later plume magmatic-hydrothermal activities led to the appearance of moderately alkaline igneous rocks (monzogabbro, trachybasalt, trachyandesite, subalkaline gabbro, and metasomatized peridotites) with a significant subduction geochemical fingerprint.

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50

Lees, G. J. "The geochemical character of late Cadomian extensional magmatism in Jersey, Channel Islands." Geological Society, London, Special Publications 51, no. 1 (1990): 273–91. http://dx.doi.org/10.1144/gsl.sp.1990.051.01.17.

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Journal articles on the topic 'Magmatisme – Islande'

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