Log in

Relevant bibliographies by topics / Lava geochemical composition / Journal articles

To see the other types of publications on this topic, follow the link: Lava geochemical composition.

Journal articles on the topic 'Lava geochemical composition'

Author: Grafiati

Published: 4 June 2021

Last updated: 1 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Lava geochemical composition.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Dudás, Francis Ö., and Rigel L. Lustwerk. "Geochemistry of the Little Dal basalts: continental tholeiites from the Mackenzie Mountains, Northwest Territories, Canada." Canadian Journal of Earth Sciences 34, no. 1 (1997): 50–58. http://dx.doi.org/10.1139/e17-004.

Full text

Abstract:

Analyses of the Little Dal lavas and the 779 Ma Tsezotene sills, both of the Mackenzie Mountains Supergroup, Northwest Territories, Canada, show them to be continental tholeiites that are geochemically related. The plagioclase- and clinopyroxene-phyric lavas are geochemically evolved and enriched in iron (up to 20.2 wt.% as Fe2O3). Two magmatic lineages are identifiable and may represent different degrees of partial melting in the same source region, but cannot be related by fractional crystallization. Within each lineage, geochemical variation can be explained by fractional crystallization in

APA, Harvard, Vancouver, ISO, and other styles

2

Uyanık, C., and K. Koçak. "GEOCHEMICAL CHARACTERISTICS OF THE ERENLERDAGI VOLCANICS, KONYA, CENTRAL TURKEY." Bulletin of the Geological Society of Greece 50, no. 4 (2017): 2057. http://dx.doi.org/10.12681/bgsg.11952.

Full text

Abstract:

Late Miocene to Pliocene volcanism produced lava domes with mafic microgranular enclaves (MMEs), nuée ardentes and pyroclastic fall and flow (ignimbrites) deposits in the WSW and NW of Konya city. All samples are predominantly high K-calc alkaline in composition but calc-alkaline and shoshonitic composition also exist. The felsic volcanics are mainly dacite, andesite, basaltic trachyandesite and rare trachyandesite in compositon. But, the MMEs have basaltic andesite and andesite compositon. SiO2 increases with decreasing TiO2, FeOt, MgO and CaO, suggesting fractional crystallization of mafic m

APA, Harvard, Vancouver, ISO, and other styles

3

Elliot, David H., and Thomas H. Fleming. "Chapter 2.1b Ferrar Large Igneous Province: petrology." Geological Society, London, Memoirs 55, no. 1 (2021): 93–119. http://dx.doi.org/10.1144/m55-2018-39.

Full text

Abstract:

AbstractThe Lower Jurassic Ferrar Large Igneous Province consists predominantly of intrusive rocks, which crop out over a distance of 3500 km. In comparison, extrusive rocks are more restricted geographically. Geochemically, the province is divided into the Mount Fazio Chemical Type, forming more than 99% of the exposed province, and the Scarab Peak Chemical Type, which in the Ross Sea sector is restricted to the uppermost lava. The former exhibits a range of compositions (SiO2= 52–59%; MgO = 9.2–2.6%; Zr = 60–175 ppm; Sri= 0.7081–0.7138;εNd= −6.0 to −3.8), whereas the latter has a restricted

APA, Harvard, Vancouver, ISO, and other styles

4

Rouquet, Simon, Pierre Boivin, Patrick Lachassagne, and Emmanuel Ledoux. "A 3-D genetic approach to high-resolution geological modelling of the volcanic infill of a paleovalley system. Application to the Volvic catchment (Chaîne des Puys, France)." Bulletin de la Société Géologique de France 183, no. 5 (2012): 395–407. http://dx.doi.org/10.2113/gssgfbull.183.5.395.

Full text

Abstract:

Abstract The Volvic natural mineral water is catched in a complex volcanic aquifer located in the northern part of the “Chaîne des Puys” volcanic system (Auvergne, France). In the watershed, water transits through scoria cones and basaltic to trachybasaltic lava flows. These aa lava flows, emitted by strombolian cones between 75,000 and 10,000 years ago, are emplaced in deep paleovalleys incised within the variscan crystalline bedrock. The volcanic infill is highly heterogeneous. In order to build a hydrogeological model of the watershed, a simple but robust methodology was developed to recons

APA, Harvard, Vancouver, ISO, and other styles

5

Teng, Fang-Zhen, Yan Hu, and Catherine Chauvel. "Magnesium isotope geochemistry in arc volcanism." Proceedings of the National Academy of Sciences 113, no. 26 (2016): 7082–87. http://dx.doi.org/10.1073/pnas.1518456113.

Full text

Abstract:

Incorporation of subducted slab in arc volcanism plays an important role in producing the geochemical and isotopic variations in arc lavas. The mechanism and process by which the slab materials are incorporated, however, are still uncertain. Here, we report, to our knowledge, the first set of Mg isotopic data for a suite of arc lava samples from Martinique Island in the Lesser Antilles arc, which displays one of the most extreme geochemical and isotopic ranges, although the origin of this variability is still highly debated. We find the δ26Mg of the Martinique Island lavas varies from −0.25 to

APA, Harvard, Vancouver, ISO, and other styles

6

Agus Widiarso, Dian, Roynaldo Lumbanbatu, Vergania Nurlita Putri, and Jenian Marin. "Development of Andesite Utilization in Gunung Ragas, Clering, Jepara, in the Industrial Sector Based on Petrological and Geochemical Data Analysis." E3S Web of Conferences 202 (2020): 05008. http://dx.doi.org/10.1051/e3sconf/202020205008.

Full text

Abstract:

The research area was the exposed extruded igneous lava rock in Clering which became the mining location of PT Semarang Mineral Pembangunan in Clering, Donorejo, Jepara with an area of ± 11 ha. This study aims to identify and determine the composition of andesite minerals by macroscopic and microscopic, the main oxide compound data, the use of andesite in industrial sector. The lithology consisted of andesite lava textured, plagioclase, leucite, clinopyroxene, sanidine as phenocryst and ground mass in the form of microlithic andesite lava as a trachytic texture. The hardness of lithology tends

APA, Harvard, Vancouver, ISO, and other styles

7

Vasilatos, Ch, M. Vlachou-Tsipoura, and M. G. Stamatakis. "ON THE OCCURRENCE OF A VOLCANIC ASH LAYER IN THE XYLOKASTRO AREA, NORTH PELOPONNESUS, GREECE: MINERALOGY AND GEOCHEMISTRY." Bulletin of the Geological Society of Greece 43, no. 5 (2017): 2773. http://dx.doi.org/10.12681/bgsg.11683.

Full text

Abstract:

This paper reports, for the first time, the occurrence of an ash layer intercalated within the Plio-Pleistocene lacustrine deposits near Xylokastro area, North Peloponnesus, Greece. Petrographic and geochemical characteristics of the ash layer are the basis of this study. An attempt was made to correlate the present findings to the reported data from other ash deposits. The composition of the ash bed showed a dacitic to rhyolitic calc alkaline suit. The geochemistry of the volcanic ash indicates high crustal contamination of the lava and points to an origin from the northwest part of the Aegea

APA, Harvard, Vancouver, ISO, and other styles

8

Humbert, F., A. Hofmann, M. de Kock, A. Agangi, Y.-M. Chou, and P. W. Mambane. "A geochemical study of the Crown Formation and Bird Member lavas of the Mesoarchaean Witwatersrand Supergroup, South Africa." South African Journal of Geology 124, no. 3 (2021): 663–84. http://dx.doi.org/10.25131/sajg.124.0022.

Full text

Abstract:

Abstract The ca. 2.97 to 2.80 Ga Witwatersrand Supergroup, South Africa, represents the oldest intracontinental sedimentary basin of the Kaapvaal craton. Two volcanic units occur in this supergroup: the widespread Crown Formation lavas in the marine shale-dominated West Rand Group and the more geographically restricted Bird Member lavas, intercalated with fluvial to fluvio-deltaic sandstone and conglomerate of the Central Rand Group. These units remain poorly studied as they are rarely exposed and generally deeply weathered when cropping out. We report whole-rock major and trace elements, Hf a

APA, Harvard, Vancouver, ISO, and other styles

9

Kanellopoulos, Christos, George Vougioukalakis, Constantinos Mavrogonatos, Ifigeneia Megremi, and Ioannis Iliopoulos. "Mineralogical, Petrological and Geochemical Study of the Agios Ioannis Volcanic Rocks, Kamena Vourla Area, Greece." Bulletin of the Geological Society of Greece 55, no. 1 (2019): 274. http://dx.doi.org/10.12681/bgsg.21128.

Full text

Abstract:

The Plio-Pleistocene volcanic center of Lichades is located in the Northern Euboean Gulf, at the western extremity of the North Anatolian Fault and it is one of the most neo-tectonically active areas in Greece. Volcanic rocks are exposed in the form of lava flows and/or domes mostly in the small islands (Lichades) offshore Kamena Vourla, as well as in a small outcrop in mainland, namely the Agios Ioannis area. Based on the results of the present study, the Agios Ioannis volcanic rocks are characterized as trachyandesites with high-K calc-alkaline affinities, similar to several volcanic rocks f

APA, Harvard, Vancouver, ISO, and other styles

10

Halama, Ralf, Jean-Louis Joron, Benoît Villemant, Gregor Markl, and Michel Treuil. "Trace element constraints on mantle sources during mid-Proterozoic magmatism: evidence for a link between the Gardar (South Greenland) and Abitibi (Canadian Shield) mafic rocks." Canadian Journal of Earth Sciences 44, no. 4 (2007): 459–78. http://dx.doi.org/10.1139/e06-108.

Full text

Abstract:

Trace and major element compositions of mid-Proterozoic (1.20–1.16 Ga) basaltic lava flows and dikes from the Gardar Province (South Greenland) provide evidence for two geochemically distinct magma sources. Based on distinct features of incompatible trace element ratios, such as Th/Ta, Th/Tb, or Th/Hf, they differ by the composition of their mantle source and by their partial melting trends. One mantle source is compositionally transitional between mid-ocean ridge basalt (MORB)-type and ocean-island basalt (OIB)-type sources with relatively low Ta/Hf ratios (~0.2), moderate enrichment in light

APA, Harvard, Vancouver, ISO, and other styles

11

Gilbert, J. S. "The stratigraphy of a proximal late Hercynian pyroclastic sequence: the Vilancós region of the Pyrenees." Geological Magazine 128, no. 2 (1991): 111–28. http://dx.doi.org/10.1017/s0016756800018318.

Full text

Abstract:

AbstractVolcanic activity, the result of crustal differentiation during the Hercynian orogeny, generated eight explosive eruptions in the Vilancós region of the Spanish Pyrenees. The volcanic products comprise the Erill Castell Volcanic Formation of Stephanian age, which crops out as a 20 km long, WNW-trending strip < 2 km wide dipping steeply to the south.The Vilancós region represents a small fragment of an originally extensive regional terrain of silicic centres.The explosive eruptions mainly generated strongly peraluminous and phenocrystal garnet-bearing subaerial ignimbrite facies. Pro

APA, Harvard, Vancouver, ISO, and other styles

12

Picard, Christian, and Michel Piboule. "Pétrologie des roches volcaniques du sillon de roches vertes archéennes de Matagami – Chibougamau à l'ouest de Chapais (Abitibi est, Québec).1. Le groupe basal de Roy." Canadian Journal of Earth Sciences 23, no. 4 (1986): 561–78. http://dx.doi.org/10.1139/e86-056.

Full text

Abstract:

In the northeastern part of the Abitibi orogenic belt, the Archean Matagami–Chibougamou greenstone belt (2700 Ma) includes a basal volcanic sequence named the Roy Group, unconformably overlain by a volcano-sedimentary series called the Opemisca Group.The Roy Group, to the west of the town of Chapais, consists of a thick, stratified, and polycyclic volcanic series (thickness = 11 000 m) resembling the large, western Abitibi submarine stratovolcanoes constructed by three mafic to felsic magmatic cycles. The first cycle (Chrissie Formation) shows lateral spreading and is composed only of a meta-a

APA, Harvard, Vancouver, ISO, and other styles

13

ABDEL-RAHMAN, ABDEL-FATTAH M. "Mesozoic volcanism in the Middle East: geochemical, isotopic and petrogenetic evolution of extension-related alkali basalts from central Lebanon." Geological Magazine 139, no. 6 (2002): 621–40. http://dx.doi.org/10.1017/s0016756802006829.

Full text

Abstract:

Mesozoic picritic and alkali basalts from central Lebanon represent a significant part of an extension-related Upper Jurassic to Upper Cretaceous discontinuous volcanic belt which occurs throughout the Middle East. Volcanism was associated with an episode of intraplate extension that followed a period of continental break-up, where Mesozoic micro-continental blocks separated from Gondwana as the Neotethys ocean opened in Jurassic times. This volcanic episode produced mafic lava flows ranging in thickness from 5 to 20 m, along with some minor pyroclastic flows. These flows are stratigraphically

APA, Harvard, Vancouver, ISO, and other styles

14

Hurai, Vratislav, Monika Huraiová, and Patrik Konečný. "REE Minerals as Geochemical Proxies of Late-Tertiary Alkalic Silicate ± Carbonatite Intrusions Beneath Carpathian Back-Arc Basin." Minerals 11, no. 4 (2021): 369. http://dx.doi.org/10.3390/min11040369.

Full text

Abstract:

The accessory mineral assemblage (AMA) of igneous cumulate xenoliths in volcanoclastic deposits and lava flows in the Carpathian back-arc basin testifies to the composition of intrusive complexes sampled by Upper Miocene-Pliocene basalt volcanoes. The magmatic reservoir beneath Pinciná maar is composed of gabbro, moderately alkalic to alkali-calcic syenite, and calcic orthopyroxene granite (pincinite). The intrusive complex beneath the wider area around Fiľakovo and Hajnáčka maars contains mafic cumulates, alkalic syenite, carbonatite, and calc-alkalic granite. Both reservoirs originated durin

APA, Harvard, Vancouver, ISO, and other styles

15

BAUER, W., W. FIELITZ, J. JACOBS, C. M. FANNING, and G. SPAETH. "Mafic Dykes from Heimefrontfjella and implications for the post-Grenvillian to pre-Pan-African geological evolution of western Dronning Maud Land, Antarctica." Antarctic Science 15, no. 3 (2003): 379–91. http://dx.doi.org/10.1017/s0954102003001391.

Full text

Abstract:

Two groups of geochemical different dykes have been identified in the Grenville-aged basement of Heimefrontfjella. The first group comprises dykes of continental tholeiite composition which probably intruded during the final stage of indentation of the Kaapvaal—Grunehogna Craton into Laurentia. One dyke of this group yielded an U—Pb zircon SHRIMP age of 1033 ± 7 Ma. The second group has an E-type MORB composition and may be related to ocean floor basalts of the Mozambique Ocean between East and West Gondwana. A preliminary U—Pb SHRIMP age of 586 ± 7 Ma for a single zircon crystal was obtained

APA, Harvard, Vancouver, ISO, and other styles

16

Chamberlain, K. J., J. Barclay, K. J. Preece, R. J. Brown, and J. P. Davidson. "Lower Crustal Heterogeneity and Fractional Crystallization Control Evolution of Small-volume Magma Batches at Ocean Island Volcanoes (Ascension Island, South Atlantic)." Journal of Petrology 60, no. 8 (2019): 1489–522. http://dx.doi.org/10.1093/petrology/egz037.

Full text

Abstract:

Abstract Ocean island volcanoes erupt a wide range of magmatic compositions via a diverse range of eruptive styles. Understanding where and how these melts evolve is thus an essential component in the anticipation of future volcanic activity. Here we examine the role of crustal structure and magmatic flux in controlling the location, evolution and ultimately composition of melts at Ascension Island. Located in the South Atlantic, Ascension Island is an ocean island volcano that has produced a continuum of eruptive compositions from basalt to rhyolite in its 1 Myr subaerial eruptive history. Vo

APA, Harvard, Vancouver, ISO, and other styles

17

Cole, R. P., J. D. L. White, D. B. Townsend, G. S. Leonard, and C. E. Conway. "Glaciovolcanic emplacement of an intermediate hydroclastic breccia-lobe complex during the penultimate glacial period (190–130 ka), Ruapehu volcano, New Zealand." GSA Bulletin 132, no. 9-10 (2020): 1903–13. http://dx.doi.org/10.1130/b35297.1.

Full text

Abstract:

Abstract An intermediate-composition hydroclastic breccia deposit is exposed in the upper reaches of a deep glacial valley at Ruapehu volcano, New Zealand, indicating an ancient accumulation of water existed near the current summit area. Lobate intrusions within the deposit have variably fluidal and brecciated margins, and are inferred to have been intruded while the deposit was wet and unconsolidated. The tectonic setting, elevation of Ruapehu, and glacial evidence suggest that the deposit-forming eruption took place in meltwater produced from an ancient glacier. The breccia-lobe complex is i

APA, Harvard, Vancouver, ISO, and other styles

18

David, Jean, and Clément Gariépy. "Early Silurian orogenic andesites from the central Quebec Appalachians." Canadian Journal of Earth Sciences 27, no. 5 (1990): 632–43. http://dx.doi.org/10.1139/e90-060.

Full text

Abstract:

The Pointe aux Trembles Formation is a deep- to shallow-water volcaniclastic apron with massive lava flows deposited in Early Silurian time. The apron deposits extend laterally to a deep-water accumulation of finer grained siliciclastic and tuffaceous material intruded by gabbroic sills, defined as the Lac Raymond Formation. The suite has most of the characteristics of high-K orogenic andesites. The lavas are highly porphyritic, with plagioclase and augite as major phenocrysts, subordinate orthopyroxene (chlorite pseudomorph), and rare hastingsitic hornblende. They form a continuous series tha

APA, Harvard, Vancouver, ISO, and other styles

19

Lebedev, V. A., G. T. Vashakidze, A. V. Parfenov, and A. I. Yakushev. "The origin of adakite-like magmas in the modern continental ollision zone: evidence from pliocene dacitic volcanism of the Akhalkalaki lava plateau (Javakheti highland, Lesser Kaucasus)." Петрология 27, no. 3 (2019): 327–51. http://dx.doi.org/10.31857/s0869-5903273327-351.

Full text

Abstract:

The paper reports the isotope-geochronological and petrological-geochemical studies of the Pliocene moderately-acid volcanism of the Akhalkalaki Plateau in the central part of the Lesser Caucasus (Javakheti highland, Georgia). K-Ar dating showed that young dacitic lavas and pyroclastic rocks were formed in the Mid-Pliocene (3.28 ± 0.10 Ma) in relation with the explosive–effusive eruptions of small composite volcanic cones and formation of minor extrusive domes confined mainly to the eastern margin of the region. Isotope-geochronological data in the combination with results of structural drilli

APA, Harvard, Vancouver, ISO, and other styles

20

Pelullo, C., G. Cirillo, R. S. Iovine, et al. "Geochemical and Sr–Nd isotopic features of the Zaro volcanic complex: insights on the magmatic processes triggering a small-scale prehistoric eruption at Ischia island (south Italy)." International Journal of Earth Sciences 109, no. 8 (2020): 2829–49. http://dx.doi.org/10.1007/s00531-020-01933-6.

Full text

Abstract:

Abstract The prehistoric (< 7 ka) Zaro eruption at Ischia island (Southern Italy) produced a lava complex overlaying a pyroclastic deposit. Although being of low energy, the Zaro eruption might have caused casualties among the neolithic population that inhabited that area of Ischia, and damages to their settlements. A similar eruption at Ischia with its present-day population would turn into a disaster. Therefore, understanding the magmatic processes that triggered the Zaro eruption would be important for volcanic hazard assessment and risk mitigation, so as to improve a knowledge that can

APA, Harvard, Vancouver, ISO, and other styles

21

Guilbaud, Marie-Noëlle, Athziri Hernández-Jiménez, Claus Siebe, and Sergio Salinas. "Las Cabras volcano, Michoacán-Guanajuato Volcanic Field, México: Topographic, climatic, and shallow magmatic controls on scoria cone eruptions." Revista Mexicana de Ciencias Geológicas 38, no. 2 (2021): 101–21. http://dx.doi.org/10.22201/cgeo.20072902e.2021.2.1645.

Full text

Abstract:

Scoria cones are abundant in most volcanic fields on Earth, such as the Michoacán-Guanajuato Volcanic Field, in the central-western sector of the Trans-Mexican Volcanic Belt. However, there are few in-depth studies on their eruptive style and controlling factors, despite of their diversity in shape and composition which implies a wide range of hazards. Here, we present results of morphologic, stratigraphic, sedimentary, petrographic, and geochemical studies of the prominent Las Cabras scoria cone located west of the Zacapu lacustrine basin in the center of the Michoacán-Guanajuato Volcanic Fie

APA, Harvard, Vancouver, ISO, and other styles

22

Novikov, D. A., A. I. Gordeeva, A. V. Chernykh, F. F. Dultsev, and L. M. Zhitova. "The Influence of Trap Magmatism on the Geochemical Composition of Brines of Petroliferous Deposits in the Western Areas of the Kureika Syneclise (Siberian Platform)." Russian Geology and Geophysics 62, no. 6 (2021): 701–19. http://dx.doi.org/10.2113/rgg20194079.

Full text

Abstract:

Abstract —We present the results of study of the influence of trap magmatism on the geochemical composition of brines and on the geothermal regime of the Earth’s interior in the western areas of the Kureika syneclise. The Siberian trap province, which unites all cutting and layered tholeiite–basic magmatic intrusions and erupted basaltic lava, is the world’s largest Phanerozoic continental basalt province. Brines, hydrocarbon deposits, and organic matter of the sedimentary cover were subjected to a significant thermal impact as a result of the Permo-Triassic trap magmatism. During the trap int

APA, Harvard, Vancouver, ISO, and other styles

23

Abdel-Rahman, Abdel-Fattah M., and P. Stephen Kumarapeli. "Geochemistry of mantle-related intermediate rocks from the Tibbit Hill volcanic suite, Quebec Appalachians." Mineralogical Magazine 62, no. 04 (1998): 487–500. http://dx.doi.org/10.1180/002646198547864.

Full text

Abstract:

Abstract We present a study on major and trace element geochemistry of some intermediate lithologies from the predominantly basaltic Tibbit Hill volcanic suite in the Humber Zone of the Quebec Appalachians. The intermediate rocks probably formed as lava flows in the volcanic sequence. Their presence shows that this rift-related, c. 554 Ma volcanic sequence is not bimodal (basaltic-comenditic) as previously thought, but consists of a spectrum of compositions ranging from mafic through intermediate to felsic lithologies. The entire volcanic sequence is poly-deformed and generally metamorphosed t

APA, Harvard, Vancouver, ISO, and other styles

24

Pouclet, André, Siaka Doumbia, and Max Vidal. "Geodynamic setting of the Birimian volcanism in central Ivory Coast (western Africa) and its place in the Palaeoproterozoic evolution of the Man Shield." Bulletin de la Société Géologique de France 177, no. 2 (2006): 105–21. http://dx.doi.org/10.2113/gssgfbull.177.2.105.

Full text

Abstract:

Abstract Palaeoproterozoic volcanic formations having different geochemical features are described in the Katiola-Marabadiassa area (Central Ivory Coast). They consist of (i) metamorphic mafic rocks belonging to the greenstone belts, (ii) rhyodacites intruded into the greenstone belts and interpreted as sub-volcanic apophyses of TTG plutons, and (iii) calc-alkaline andesitic lava interbedded in the lower sedimentary pile of the Bandama Basin. The greenstone belt rocks have a magmatic signature of ocean floor tholeiites. They were generated from moderate partial melting of a fairly depleted spi

APA, Harvard, Vancouver, ISO, and other styles

25

Giuliani, Andrea, Matthew G. Jackson, Angus Fitzpayne, and Hayden Dalton. "Remnants of early Earth differentiation in the deepest mantle-derived lavas." Proceedings of the National Academy of Sciences 118, no. 1 (2020): e2015211118. http://dx.doi.org/10.1073/pnas.2015211118.

Full text

Abstract:

The noble gas isotope systematics of ocean island basalts suggest the existence of primordial mantle signatures in the deep mantle. Yet, the isotopic compositions of lithophile elements (Sr, Nd, Hf) in these lavas require derivation from a mantle source that is geochemically depleted by melt extraction rather than primitive. Here, this apparent contradiction is resolved by employing a compilation of the Sr, Nd, and Hf isotope composition of kimberlites—volcanic rocks that originate at great depth beneath continents. This compilation includes kimberlites as old as 2.06 billion years and shows t

APA, Harvard, Vancouver, ISO, and other styles

26

Abdel-Rahman, Abdel-Fattah M. "Pan-African volcanism: petrology and geochemistry of the Dokhan Volcanic Suite in the northern Nubian shield." Geological Magazine 133, no. 1 (1996): 17–31. http://dx.doi.org/10.1017/s0016756800007226.

Full text

Abstract:

AbstractThe Late Proterozoic Dokhan volcanic suite (620 Ma) of the northern Nubian shield is the product of Late Pan-African volcanism. The suite covers the entire spectrum from basalt to high-silica rhyolite and occurs as two units: a dark-coloured unit containing basalt-andesite-dacite, and a light-coloured unit encompassing dacite-rhyodacite-rhyolite. The latter unit is made up largely of ash flow tuffs and ign-imbrites that are locally interstratified with basalt and andesite lava flows. The suite forms a continuum in composition with a wide range of Si02 (48–77 wt%), CaO (0.1–8.9 wt%), Sr

APA, Harvard, Vancouver, ISO, and other styles

27

Breitkreuz, Christoph, Alexandra Käßner, Marion Tichomirowa, Manuel Lapp, Shan Huang, and Klaus Stanek. "The Late Carboniferous deeply eroded Tharandt Forest caldera–Niederbobritzsch granite complex: a post-Variscan long-lived magmatic system in central Europe." International Journal of Earth Sciences 110, no. 4 (2021): 1265–92. http://dx.doi.org/10.1007/s00531-021-02015-x.

Full text

Abstract:

AbstractSamples and documentation of outcrops and drillings, facies analysis, whole rock geochemistry and radiometric ages have been employed to re-evaluate the Late Carboniferous Tharandt Forest caldera (TFC) and the co-genetic Niederbobritzsch granite (NBG) in the eastern Erzgebirge near Dresden, Germany. The c. 52 km2 TFC harbours strongly welded ignimbrites with a preserved minimum thickness of 550 m. Composition of initial fallout tephra at the base of the TFC fill, comprising lithics of rhyolitic and basic lava, and of silica-rich pyroclastic rocks, suggests a bimodal volcanic activity i

APA, Harvard, Vancouver, ISO, and other styles

28

Hübner, Marcel, Christoph Breitkreuz, Alexander Repstock, et al. "Evolution of the Lower Permian Rochlitz volcanic system, Eastern Germany: reconstruction of an intra-continental supereruption." International Journal of Earth Sciences 110, no. 6 (2021): 1995–2020. http://dx.doi.org/10.1007/s00531-021-02053-5.

Full text

Abstract:

AbstractExtensional tectonics in the Late Paleozoic Central Europe was accompanied by rift magmatism that triggered voluminous intracontinental caldera-forming eruptions. Among these, the Lower Permian Rochlitz Volcanic System (RVS) in the North Saxon Volcanic Complex (Eastern Germany, Saxony) represents a supereruption (VEI 8, estimated volume of 1056 km3) of monotonous rhyolites followed by monotonous intermediates. Mapping, petrography, whole-rock geochemistry along with mineral chemistry and oxygen isotopes in zircon display its complex eruption history and magma evolution. Crystal-rich (&

APA, Harvard, Vancouver, ISO, and other styles

29

HARTMANN, LÉO A., WILSON WILDNER, LAUREN C. DUARTE, et al. "Geochemical and scintillometric characterization and correlation of amethyst geode-bearing Paraná lavas from the Quaraí and Los Catalanes districts, Brazil and Uruguay." Geological Magazine 147, no. 6 (2010): 954–70. http://dx.doi.org/10.1017/s0016756810000592.

Full text

Abstract:

AbstractGeochemical studies of the six lowermost lava flows of the Cretaceous Serra Geral Formation (Paraná volcanic province) in Quaraí (Brazil) and Artigas (Uruguay) were combined with flow-by-flow field studies of structures and scintillometric profiles to establish a consistent regional stratigraphic framework over at least 100 km. This greatly improves exploration capability for amethyst and agate geodes. A basalt, colada Mata Olho (Alegrete facies, Serra Geral Formation), was the first lava to flow over the ancient Botucatu desert in the region, but an andesite, colada Catalán, overstepp

APA, Harvard, Vancouver, ISO, and other styles

30

BRUNI, SANDRO, MASSIMO D'ORAZIO, MIGUEL J. HALLER, et al. "Time-evolution of magma sources in a continental back-arc setting: the Cenozoic basalts from Sierra de San Bernardo (Patagonia, Chubut, Argentina)." Geological Magazine 145, no. 5 (2008): 714–32. http://dx.doi.org/10.1017/s0016756808004949.

Full text

Abstract:

AbstractEast of the Patagonian Andes, mafic volcanic rocks (mainly lava flows and scoriae) are exposed in the Sierra de San Bernardo fold belt and neighbouring areas (central Patagonia; 44.5–46° S, 69–71° W). They were erupted over a wide interval of time (late Eocene–Pleistocene; 14 new K–Ar ages), and show systematic chemical and Sr–Nd–Pb isotopic variations in time. The alkaline lavas (Mg number 57–66) erupted during the late Eocene and early Miocene, have an intraplate geochemical affinity, and have the highest 143Nd/144Nd and 206Pb/204Pb and the lowest 87Sr/86Sr ratios of the dataset. The

APA, Harvard, Vancouver, ISO, and other styles

31

Walker, Brett H., Michael O. Garcia та Tim R. Orr. "Petrologic Insights into Rift Zone Magmatic Interactions from the 2011 Eruption of Kīlauea Volcano, Hawaiʻi". Journal of Petrology 60, № 11 (2019): 2051–75. http://dx.doi.org/10.1093/petrology/egz064.

Full text

Abstract:

Abstract The high frequency of historical eruptions at Kīlauea Volcano presents an exceptional opportunity to address fundamental questions related to the transport, storage, and interaction of magmas within rift zones. The Nāpau Crater area on Kīlauea’s East Rift Zone (ERZ) experienced nine fissure eruptions within 50 years (1961–2011). Most of the magma intruded during these frequent eruptions remained stored within the rift zone, creating a potential magma mixing depot within the ERZ. The superbly monitored and sampled 2011 eruption (Puʻu ʻŌʻō episode 59) presents an extraordinary opportuni

APA, Harvard, Vancouver, ISO, and other styles

32

Maury, René C., Gérard Guille, Hervé Guillou, et al. "Temporal evolution of a Polynesian hotspot: New evidence from Raivavae (Austral islands, South Pacific ocean)." Bulletin de la Société Géologique de France 184, no. 6 (2013): 557–67. http://dx.doi.org/10.2113/gssgfbull.184.6.557.

Full text

Abstract:

Abstract A new geological mapping of Raivavae island, Austral-Cook linear chain, French Polynesia, combined with 10 unspiked K/Ar ages measured on its lavas, shows that it was built during two successive volcanic phases : 10.6-7.4 Ma (dykes crosscutting Rairua submarine breccias and younger subaerial Rairua flows) and 6.4-5.4 Ma (Anatonu shield volcano and associated trachytic and phonolitic domes and plugs). Geochemical data from the present study and a previous one [Lassiter et al., 2003] demonstrate that the Rairua alkali basalts, picrobasalts and basanites are more enriched in incompatible

APA, Harvard, Vancouver, ISO, and other styles

33

Nauret, F., J. E. Snow, E. Hellebrand, and D. Weis. "Geochemical Composition of K-rich Lavas from the Lena Trough (Arctic Ocean)." Journal of Petrology 52, no. 6 (2011): 1185–206. http://dx.doi.org/10.1093/petrology/egr024.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Huong, Tran Thi, and Nguyen Hoang. "Petrology, geochemistry, and Sr, Nd isotopes of mantle xenolith in Nghia Dan alkaline basalt (West Nghe An): implications for lithospheric mantle characteristics beneath the region." VIETNAM JOURNAL OF EARTH SCIENCES 40, no. 3 (2018): 207–27. http://dx.doi.org/10.15625/0866-7187/40/3/12614.

Full text

Abstract:

Study of petrological and geochemical characteristics of mantle peridotite xenoliths in Pliocene alkaline basalt in Nghia Dan (West Nghe An) was carried out. Rock-forming clinopyroxenes, the major trace element containers, were separated from the xenoliths to analyze for major, trace element and Sr-Nd isotopic compositions. The data were interpreted for source geochemical characteristics and geodynamic processes of the lithospheric mantle beneath the region. The peridotite xenoliths being mostly spinel-lherzolites in composition, are residual entities having been produced following partial mel

APA, Harvard, Vancouver, ISO, and other styles

35

Maldonado, Florian, James R. Budahn, Lisa Peters, and Daniel M. Unruh. "Geology, geochronology, and geochemistry of basaltic flows of the Cat Hills, Cat Mesa, Wind Mesa, Cerro Verde, and Mesita Negra, central New Mexico." Canadian Journal of Earth Sciences 43, no. 9 (2006): 1251–68. http://dx.doi.org/10.1139/e06-018.

Full text

Abstract:

The geochronology, geochemistry, and isotopic compositions of basaltic flows erupted from the Cat Hills, Cat Mesa, Wind Mesa, Cerro Verde, and Mesita Negra volcanic centres in central New Mexico indicate that each of these lavas had unique origins and that the predominant mantle involved in their production was an ocean-island basalt type. The basalts from Cat Hills (0.11 Ma) and Cat Mesa (3.0 Ma) are similar in major and trace element composition, but differences in MgO contents and Pb isotopic values are attributed to a small involvement of a lower crustal component in the genesis of the Cat

APA, Harvard, Vancouver, ISO, and other styles

36

Cousens, Brian L., and Mary Lou Bevier. "Discerning asthenospheric, lithospheric, and crustal influences on the geochemistry of Quaternary basalts from the Iskut–Unuk rivers area, northwestern British Columbia." Canadian Journal of Earth Sciences 32, no. 9 (1995): 1451–61. http://dx.doi.org/10.1139/e95-117.

Full text

Abstract:

Pleistocene- to Holocene-age basaltic rocks of the Iskut–Unuk rivers volcanic field, at the southern terminus of the Stikine Volcanic Belt in the northern Canadian Cordillera, provide information on the geochemical composition of the underlying mantle and processes that have modified parental magmas. Basaltic rocks from four of the six eruptive centres are moderately evolved (MgO = 5.7–6.8%) alkaline basalts with chondrite-normalized La/Sm = 1.6–1.8, 87Sr/86Sr = 0.70336–0.70361, εNd = +4.4 to +5.9, and 206Pb/204Pb = 19.07–19.22. The small range of isotopic compositions and incompatible element

APA, Harvard, Vancouver, ISO, and other styles

37

Shane, Phil, Victoria Smith, and Ian Nairn. "Biotite composition as a tool for the identification of Quaternary tephra beds." Quaternary Research 59, no. 2 (2003): 262–70. http://dx.doi.org/10.1016/s0033-5894(03)00012-7.

Full text

Abstract:

AbstractStratigraphically important Quaternary rhyolitic tephra deposits that erupted from the Okataina and Taupo volcanic centers in New Zealand can be geochemically identified using the FeO and MgO contents of their biotite phenocrysts. The FeO/MgO ratio in biotite does not correlate with FeO/MgO in the coexisting glass phase so that tephra beds with similar glass compositions can be discriminated by their different biotite compositions. Some individual tephra deposits display sequential changes in biotite composition that allow separate phases of the eruption to be identified, greatly incre

APA, Harvard, Vancouver, ISO, and other styles

38

Timmermans, Ann C., Brian L. Cousens, and Christopher D. Henry. "Geochemical study of Cenozoic mafic volcanism in the west-central Great Basin, western Nevada, and the Ancestral Cascades Arc, California." Geosphere 16, no. 5 (2020): 1179–207. http://dx.doi.org/10.1130/ges01535.1.

Full text

Abstract:

Abstract Processes linked to shallow subduction, slab rollback, and extension are recorded in the whole-rock major-, trace-element, and Sr, Nd, and Pb isotopic compositions of mafic magmatic rocks in both time and space over southwestern United States. Eocene to Mio-Pliocene volcanic rocks were sampled along a transect across the west-central Great Basin (GB) in Nevada to the Ancestral Cascade Arc (ACA) in the northern Sierra Nevada, California (∼39°–40° latitude), which are interpreted to represent a critical segment of a magmatic sweep that occurred as a result of subduction from east-northe

APA, Harvard, Vancouver, ISO, and other styles

39

Zong, Tong, Zheng-Gang Li, Yan-Hui Dong, et al. "Geochemical Constraints on Mantle Melting and Magma Genesis at Pohnpei Island, Micronesia." Minerals 10, no. 9 (2020): 816. http://dx.doi.org/10.3390/min10090816.

Full text

Abstract:

The lithospheric mantle is of paramount importance in controlling the chemical composition of ocean island basalts (OIBs), influencing partial melting and magma evolution processes. To improve the understanding of these processes, the pressure–temperature conditions of mantle melting were investigated, and liquid lines of descent were modelled for OIBs on Pohnpei Island. The studied basaltic samples are alkalic, and can be classified as SiO2-undersaturated or SiO2-saturated series rocks, with the former having higher TiO2 and FeOT contents but with no distinct trace-element composition, sugges

APA, Harvard, Vancouver, ISO, and other styles

40

HAILEAB, BEREKET, FRANCIS H. BROWN, IAN McDOUGALL, and PATRICK N. GATHOGO. "Gombe Group basalts and initiation of Pliocene deposition in the Turkana depression, northern Kenya and southern Ethiopia." Geological Magazine 141, no. 1 (2004): 41–53. http://dx.doi.org/10.1017/s001675680300815x.

Full text

Abstract:

A little before 4 Ma ago, deposition of Pliocene and Pleistocene strata described as the Omo Group began in the Turkana and Omo basins of northern Kenya and southern Ethiopia. Soon after, basaltic magma erupted as thin lava flows, and intruded as dykes into the oldest Pliocene strata of the basin. These flows and intrusions are similar petrographically and geochemically, and mark a basaltic magmatic event spanning latitudes from 2° 45′ N to 6° 45′ N at a longitude of about 36° E. By 3.94 Ma, this basaltic magmatic activity had ceased. Previous researchers used these lavas as an important seism

APA, Harvard, Vancouver, ISO, and other styles

41

Rollinson, H. R. "Another look at the constant sum problem in geochemistry." Mineralogical Magazine 56, no. 385 (1992): 469–75. http://dx.doi.org/10.1180/minmag.1992.056.385.03.

Full text

Abstract:

AbstractCompositional data—that is data where concentrations are expressed as proportions of a whole, such as percentages or parts per million—have a number of peculiar mathematical properties which make standard statistical tests unworkable. In particular correlation analysis can produce geologically meaningless results. Aitchison (1986) proposed a log-ratio transformation of compositional data which allows inter-element relationships to be investigated. This method was applied to two sets of geochemical data—basalts from Kilauea Iki lava lake and grantic gneisses from the Limpopo Belt—and ge

APA, Harvard, Vancouver, ISO, and other styles

42

Wang, Dong-Bing, Bao-Di Wang, Fu-Guang Yin, et al. "Petrogenesis and tectonic implications of Late Mesoproterozoic A1- and A2-type felsic lavas from the Huili Group, southwestern Yangtze Block." Geological Magazine 156, no. 08 (2019): 1425–39. http://dx.doi.org/10.1017/s0016756818000882.

Full text

Abstract:

AbstractThis paper presents new LA-ICP-MS zircon U–Pb chronology, whole-rock geochemical and zircon Hf isotopic data for the felsic lavas of the Huili Group from the southwestern Yangtze Block. LA-ICP-MS zircon U–Pb dating shows that these rocks were emplaced in Late Mesoproterozoic time (∼1028 to 1019 Ma). Relative to typical I-type and S-type granitoids, all the samples are characterized by low Sr and Eu, and high high-field-strength element contents, highTFeO/MgO, enriched rare earth element compositions and negative Eu anomalies, indicating that they share the geochemical signatures of A-t

APA, Harvard, Vancouver, ISO, and other styles

43

Parfenov, A. V., V. A. Lebedev, I. V. Chernyshev, et al. "Petrological-geochemical characteristics of lavas, sources and evolution of magmatic melts of the Kazbek neovolcanic center (Greater Caucasus)." Петрология 27, no. 6 (2019): 658–89. http://dx.doi.org/10.31857/s0869-5903276658-689.

Full text

Abstract:

The results of petrological-geochemical and isotope-geochemical studies of the Late Pleistocene-Holocene lavas of the Kazbek Neovolcanic Center, one of the largest centers of youngest magmatism in the Greater Caucasus, are presented. It has been established that the volcanic rocks of the Kazbek center arise a continuous compositional series basaltic (trachy-)andesites(trachy-)andesitesdacites with a predominance of calc-alkaline intermediate and moderately-acid lavas. The obtained results indicate that the processes of fractional crystallization and mixing of melts had a leading role in

APA, Harvard, Vancouver, ISO, and other styles

44

Ujike, Osamu, and A. M. Goodwin. "Geochemistry and origin of Archean felsic metavolcanic rocks, central Noranda area, Quebec, Canada." Canadian Journal of Earth Sciences 24, no. 12 (1987): 2551–67. http://dx.doi.org/10.1139/e87-238.

Full text

Abstract:

Felsic magma petrogenesis was studied by analyzing 24 stratigraphically controlled Archean andesite-to-rhyolite lava flows of both tholeiitic and calc-alkalic affinity from the upper Noranda Subgroup, Quebec, using instrumental neutron activation and X-ray fluorescence techniques. The lavas have moderate values of [La/Yb]N (0.9–3.8) and low values of 100 × Th/Zr (~1). According to calculations following batch partial melting and Rayleigh fractional crystallization models, both the calc-alkalic and tholeiitic felsic volcanic rocks are probably products of shallow-level fractional crystallizatio

APA, Harvard, Vancouver, ISO, and other styles

45

Richter, Marianne, Oliver Nebel, Roland Maas, et al. "An Early Cretaceous subduction-modified mantle underneath the ultraslow spreading Gakkel Ridge, Arctic Ocean." Science Advances 6, no. 44 (2020): eabb4340. http://dx.doi.org/10.1126/sciadv.abb4340.

Full text

Abstract:

Earth’s upper mantle, as sampled by mid-ocean ridge basalts (MORBs) at oceanic spreading centers, has developed chemical and isotopic heterogeneity over billions of years through focused melt extraction and re-enrichment by recycled crustal components. Chemical and isotopic heterogeneity of MORB is dwarfed by the large compositional spectrum of lavas at convergent margins, identifying subduction zones as the major site for crustal recycling into and modification of the mantle. The fate of subduction-modified mantle and if this heterogeneity transmits into MORB chemistry remains elusive. Here,

APA, Harvard, Vancouver, ISO, and other styles

46

Pe-Piper, Georgia, and Lubomir F. Jansa. "Triassic olivine-normative diabase from Northumberland Strait, eastern Canada: implications for continental rifting." Canadian Journal of Earth Sciences 23, no. 7 (1986): 1013–21. http://dx.doi.org/10.1139/e86-102.

Full text

Abstract:

Two intervals of mafic igneous rocks were encountered within a Silurian to Carboniferous sequence in an exploratory offshore well located in the Gulf of St. Lawrence, eastern Canada. Geochemical and radiometric analyses show that the lower mafic rocks are Early Silurian continental tholeiite lavas, with their radiogenic clock thermally reset during the Late Devonian. The upper igneous interval consists of several dikes of high-alumina diabase characterized by flat, relatively unenriched REE spectra and a positive Eu anomaly. This diabase resembles olivine tholeiites. Two K/Ar dates suggest a L

APA, Harvard, Vancouver, ISO, and other styles

47

Boudoire, G., Y. A. Brugier, A. Di Muro, et al. "Eruptive Activity on the Western Flank of Piton de la Fournaise (La Réunion Island, Indian Ocean): Insights on Magma Transfer, Storage and Evolution at an Oceanic Volcanic Island." Journal of Petrology 60, no. 9 (2019): 1717–52. http://dx.doi.org/10.1093/petrology/egz045.

Full text

Abstract:

Abstract Petrological and geochemical (major element, trace element, Sr–Nd isotope) data for recent (&lt;5 kyr old) basalts that sporadically erupt on the western flank of Piton de la Fournaise (PdF), one of the most active volcanoes on Earth, allow the tracking of magma transfer and evolution from mantle to crustal depths. In the western peripheral area of PdF we document the broadly synchronous eruptions of (1) primitive olivine and olivine–clinopyroxene transitional basalts with tholeiitic affinity that are closely associated in space with (2) transitional olivine basalts with alkaline

APA, Harvard, Vancouver, ISO, and other styles

48

Shahbazi Shiran, Habib. "Petrogenesis of Quaternary Shoshonitic Volcanism in NE Iran (Ardabil): Implication for Postcollisional Magmatism." Journal of Geological Research 2013 (December 7, 2013): 1–11. http://dx.doi.org/10.1155/2013/735498.

Full text

Abstract:

Trachyandesites, trachytes, andesites, and pyrocalstic rocks, with shoshonitic signature, are the main Quaternary volcanic rocks in the Sabalan region (Ardabil). Plagiocalse, K-feldspar, biotite associated with clinopyroxene, and glass are the main constituents of these lavas. Plagioclases are andesine to labradorite while clinopyroxenes have augitic composition. The Sabalan volcanic rocks show enrichment in LREEs (relative to HREEs) and are characterized by enrichment in LILEs and depletion in HFSEs. Petrological observations, along with rare earth and trace elements geochemistry, suggest sho

APA, Harvard, Vancouver, ISO, and other styles

49

Tegner, Christian, Sandra A. T. Michelis, Iain McDonald, et al. "Mantle Dynamics of the Central Atlantic Magmatic Province (CAMP): Constraints from Platinum Group, Gold and Lithophile Elements in Flood Basalts of Morocco." Journal of Petrology 60, no. 8 (2019): 1621–52. http://dx.doi.org/10.1093/petrology/egz041.

Full text

Abstract:

Abstract Mantle melting dynamics of the Central Atlantic Magmatic Province (CAMP) is constrained from new platinum group element (PGE), gold (Au), rare earth element (REE), and high field strength element (HFSE) data and geochemical modelling of flood basalts in Morocco. The PGE are enriched similarly to flood basalts of other large igneous provinces. The magmas did not experience sulphide saturation during fractionation and were therefore fertile. The CAMP is thus prospective for PGE and gold mineralization. The Pt/Pd ratio of the Moroccan lavas indicates that they originated by partial melti

APA, Harvard, Vancouver, ISO, and other styles

50

Peate, D. W., J. A. Pearce, C. J. Hawkesworth, H. Colley, C. M. H. Edwards, and K. Hirose. "Geochemical Variations in Vanuatu Arc Lavas: the Role of Subducted Material and a Variable Mantle Wedge Composition." Journal of Petrology 38, no. 10 (1997): 1331–58. http://dx.doi.org/10.1093/petroj/38.10.1331.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!