 | | Journal (article/letter/editorial) | | Evolution of the Nyiragongo Magma by TH. G. SAHAMA Department of Geology, University of Helsinki, Finland...5 June 1972) ABSTRACT INTRODUCTION T H E Lake Kivu volcanics in the Western Rift Valley of Central...the South Kivu basaltic rocks. On the other hand, the Virunga (Birunga) volcanic field north of the lake...Nyamuragira (Nyamlagira) and, especially, Mt. Nyiragongo (Niragongo, Niligongo), including their satellitic...lavas will be called the Nyamuragira area and the Nyiragongo area rocks, respectively. The six eastern extinct |  | | Journal (article/letter/editorial) | | Aufs~itze Mineralogical composition of the Nyiragongo rod, s By TrL G. SArr~MA,Helsinki *) With 8 figures...figures and 2 tables Dedicated to Professor Dr. A. RITTMANNon the oeeasion of his 75. birthday Zusammenfassung...Gesteinsanalysen auf die Laven des Nyiragongo-Vulkans in Nord Kivu, Republik Congo (Kinsasha). In dem hetr. vulkanischen...Basanitgruppe (m~il3ig unters~ttigt) und das Nyiragongo-Gebiet mit Gesteinen der Leuzitit-NephelinitMelilitithgruppe...Entstehung des hauptsiichlich melilitithischen Nyiragongo-Magmas mSglicherweise mit karbonatischen Anteilen |  | Minissale, Silvia, Zanetti, Alberto, Tedesco, Dario, Morra, Vincenzo, Melluso, Leone (2019) The petrology and geochemistry of Nyiragongo lavas of 2002, 2016, 1977 and 2017 AD, and the trace element partitioning between melilitite glass and melilite, nepheline, leucite, clinopyroxene, apatite, olivine and Fe-Ti oxides: a unique scenario. Lithos, 332. 296-311 doi:10.1016/j.lithos.2019.02.023 | Journal (article/letter/editorial) | | com/locate/lithos The petrology and geochemistry of Nyiragongo lavas of 2002, 2016, 1977 and 2017 AD, and the...partitioning between melilitite glass and melilite, nepheline, leucite, clinopyroxene, apatite, olivine and...81100 Caserta, Italy d JOC, UN-MONUSCO, UN-Goma, Congo b a r t i c l e i n f o Article history: Received...2019 Available online xxxx a b s t r a c t The Nyiragongo lava of 2002, and the new one flowing from the...in 2017, are multiply saturated in melilite, nepheline, leucite, clinopyroxene, olivine, apatite and |  | | Journal (article/letter/editorial) | | combeite- and götzenite-bearing nephelinite at Nyiragongo, Virunga Volcanic Province in the East African...a c t The lavas and pyroclastic rocks of Nyiragongo volcano (East African Rift) range in composition...combeite nephelinite. In peralkaline nephelinites at Nyiragongo, titanium is hosted in mineral assemblages with...(replacing melilite phenocrysts), recrystallized nepheline + kalsilite phenocryst aggregates and a range...including delhayelite. The compositions of coexisting nepheline and kalsilite in phenocryst aggregates and groundmass |  | Chakrabarti, Ramananda, Basu, Asish R., Santo, Alba P., Tedesco, Dario, Vaselli, Orlando (2009) Isotopic and geochemical evidence for a heterogeneous mantle plume origin of the Virunga volcanics, Western rift, East African Rift system. Chemical Geology, 259 (3) 273-289 doi:10.1016/j.chemgeo.2008.11.010 | Journal (article/letter/editorial) | | active Virunga volcanoes, Nyiragongo and Nyamuragira, are 15 km apart. Nyiragongo shows unusual compositions...major, trace elements and Nd–Sr–Pb isotopes in Nyiragongo and Nyamuragira lavas including samples from...from 2002, 2003 and 2004 eruptions. The youngest Nyiragongo lavas are ultrapotassic, ultrasodic and have...basanites and tephrites, distinct from the foiditic Nyiragongo lavas. Both volcanic products show enrichment...Dy/Yb suggests residual garnet in the source(s). Nyiragongo and Nyamuragira lavas show high Nb/U similar |  | | Journal (article/letter/editorial) | | and andremeyerite-bearing nephelinite from Nyiragongo volcano, East African Rift Tom Andersen a,⁎, Marlina...peralkaline leucite nephelinite from the active volcano Nyiragongo in the Virunga province of the East African...mineral. Low-variance mineral assemblages in Nyiragongo nephelinite define a cooling trend from eruptive...East African Rift (Shombole, Oldoinyo Lengai, Nyiragongo). A number of rare minerals that are characteristic...nephelinite from Nyiragongo in the Virunga volcanic province, Democratic Republic of Congo, including götzenite |  | | Report (issue) | | c = 7.085(1) X-ray Powder Pattern: Mt. Nyiragongo, Congo. 3.055 (100), 3.122 (80), 3.288 (60), 2.472...Total 100.91 100.00 34.44 36.75 (1) Mt. Nyiragongo, Congo; by electron microprobe. (2) BaFe2 Si2 O7...crystallization of an associated green glass. Association: Nepheline, leucite, clinopyroxene, kirschsteinite, melilite...Distribution: From the rim of Mt. Nyiragongo volcano, Kivu Province, Congo (Zaire). Name: To honor Andr¶e...geologist with the Geological Survey of the Belgian Congo, who ¯rst collected the mineral. Type Material: |  | Chakrabarti, Ramananda, Sims, Kenneth W.W., Basu, Asish R., Reagan, Mark, Durieux, Jacques (2009) Timescales of magmatic processes and eruption ages of the Nyiragongo volcanics from 238U-230Th-226Ra-210Pb disequilibria. Earth and Planetary Science Letters, 288 (1) 149-157 doi:10.1016/j.epsl.2009.09.017 | Journal (article/letter/editorial) | | of magmatic processes and eruption ages of the Nyiragongo volcanics from 238U-230Th-226Ra-210Pb disequilibria...assessment a b s t r a c t The silica-undersaturated Nyiragongo volcanics, located in the East African Rift,...in 13 recent and prehistoric lava samples from Nyiragongo including those from the 2002 flank eruption and...consistent with high Zr/Hf in the Nyiragongo lavas. The Nyiragongo volcanics have higher (230Th/232Th)...carbonate metasomatism less than 300 ka ago. Several Nyiragongo samples display significant 226Ra excesses implying |  | | Journal (article/letter/editorial) | | ratios (average = 0-707) than the melilite- and nepheline-bearing varieties (average = 0-705). Samples of...also for lava flows from one extensively sampled volcano. Hypotheses involving simple fractional crystallization...Birunga area at the junction of the Congo, south-west Uganda, and north-west Rwanda (see Fig. 1). The Birunga...Nyamlagira (Nyamuragira) and Nyiragongo in the Virunga province of the Congo. Most of the volcanoes in the...than olivine leucitite and has a glassy base. Nepheline-bearing varieties also are found. (2) Leucitite-Nephelinite |  | | Journal (article/letter/editorial) | | and the nepheline-kalsilite series would suggest existence of similar phenomena also in nepheline, such...necessarily fail in the case of nepheline. The hexagonal symmetry of nepheline, from which no deviation is...crystallographic axes. The ways of attack on studying nepheline must be different from those used for the feldspars...microscope heating stage. Two optical types of nepheline were distinguished on the basis of the absolute...temperature and a highJy positive optical A-value. The nepheline specimens studied represent optically a continuous |  | Burgi, P.-Y., Minissale, S., Melluso, L., Mahinda, C. K., Cuoco, E., Tedesco, D. (2018) Models of the Formation of the 29 February 2016 New Spatter Cone Inside Mount Nyiragongo. Journal of Geophysical Research: Solid Earth, 123 (11) 9469-9485 doi:10.1029/2018jb015927 | Journal (article/letter/editorial) | | 29 February 2016 new spatter cone inside Mount Nyiragongo. Journal of Geophysical Research: Solid Earth...29 February 2016 New Spatter Cone Inside Mount Nyiragongo P.-Y. Burgi1 , S. Minissale2, L. Melluso2, C...Volcanologique de Goma, Goma, Democratic Republic of Congo, 4DISTABIF, Campania University-Luigi Vanvitelli...5JOC, UN-MONUSCO, Goma, Democratic Republic of Congo 3 Abstract A new and unusual eruptive event occurred...2016 within the summit crater of the Mount Nyiragongo volcano. Based on field campaigns performed between |  | | Journal (article/letter/editorial) | | microlitic texture. Clinopyroxene, feldspathoids (nepheline, leucite, haüyne), J. Etame et al. / Chemie...4 1.4 7.5 3.4 0.5 – – 0.2 63.9 30.2 Ne: nepheline, Leu: Leucite, Hye: hauyne, Cpx: clinopyroxene...nephelinites at Nyiragongo volcano (Demant et al., 1994; Platz et al., 2004) and at Kivu (Marcelot et al...nephelinites at Mt Etinde (Nkoumbou et al., 1995) and Nyiragongo (Platz et al., 2004) such as melilite nephelinites...mineral (**) in hydrothermalized nephelinite. Nepheline Leucite Haüyne Clinopyroxene * * * *** |  | | Report (issue) | | Nepheline (Na; K)AlSiO4 ° c 2001 Mineral Data Publishing, ver sion 1.2 Crystal Data: Hexagonal. Point...Occurrence: Characteristic of alkalic rocks as nepheline syenites and gneisses, alkalic gabbros; in sodium-rich...Kola Peninsula, Russia. From the Nyiragongo volcano, Kivu Province, Congo (Zaire). In the USA, at Litch¯eld...231{270. (3) Smith, J.V. and F. Tuttle (1957) The nepheline-kalsilite system: I. X-ray data for the crystalline...Foreman, N. and D.R. Peacor (1970) Re¯nement of the nepheline structure at several temperatures. Zeits. Krist |  | | Journal (article/letter/editorial) | | melilite and nepheline (melilite nephelinites) from the Nyiragongo volcano of the Congo and a group rich...(the melilite nephelinite of the lava lake of Nyiragongo) through the Cameroons etindite (clinopyroxene...includes a number of lavas of the Nyiragongo Crater area of the Congo and an etindite from the Cameroons...nephelinites which hold phenocrysts of melilite and nepheline, one also carrying leucite (VM 220) and another...consisting of a core of perthitic nepheline-kalsilite surrounded by a nepheline margin (FEAE 83). The lava of |  | | Journal (article/letter/editorial) | | BP 190, Kinshasa XI, Democratic Republic of the Congo diffusion-controlled melting models), or in a phlogopitebearing...Metasomatism · Virunga volcanic field · Mugogo volcano · Carbonatite Introduction The Virunga volcanic...emitting basalts, basanites and tephrites, and the Nyiragongo erupting foiditic lavas (melilitites, 13 29...west branch are indicated (TA Toro-Ankole, SK South Kivu, R Rungwe). Stippled areas mark the extension of...its eight stratovolcanoes (N Nyamuragira, Ny Nyiragongo, M Mikeno, K Karisimbi, V Visoke, S Sabinyo, |  | | Journal (article/letter/editorial) | | nephelinites (.13.5% normative nepheline) are restricted to Kiejo volcano in the southern portion of the...individual volcanoes, although lavas from each volcano reflect a range in degree of melting. Significantly...1): Toro-Ankole (Uganda), Virunga (Zaire-Rwanda), Kivu (Zaire-Burundi) and Rungwe (Tanzania). In these...basanites are common in the southern provinces (Kivu and Rungwe). Detailed studies have also revealed...post-Miocene shield volcanoes, with satellite craters on volcano flanks and explosion craters along NW-SE trending |  | | Journal (article/letter/editorial) | | Virunga) volcanic province (Fig. 1) is situated north of Lake Kivu. The most important and still active volcanoes...are Nyamuragira and Nyiragongo. According to Sahama (1973) the Nyiragongo volcano is mostly composed of...phonolitic to tephritic foidite. The Nyamuragira volcano shows tephritic to phonolitic rocks too. Sabordinated...basaltic rocks of ~outh Kivu is about 0.3. The volcanic activity in the South Kivu provirce began in Lower...Lueshe is located in the Ruindi Mountains of North Kivu (NE-gaire)~ about 40 km SSW of Lake ~ w a r d |  | | Journal (article/letter/editorial) | | Peninsula. Of course, the presence of oily gas in nepheline syenites did not demolish t For the first time...mineral was discovered in Africa, in the Belgian Congo (now in them. Thus, it can be suggested that aluminum...in calcilite-bearing melilite-nepheline lavas of the Nyiragongo Volcano as during gas synthesis. Later...not taken into account. T1 adularia, aegirine, nepheline, eudialyte, and two new minerals - fenaksite and...being very perfect SAHAMATH.J. Why is Mt. Nyiragongo a volcano of outstanding mineralogic along (010) and |  | | Journal (article/letter/editorial) | | INTRODUCTION Esch (1901) described Mt Etinde as a volcano built (1983) and of Peterson (1989a, 19894). •Present...of Birmingham on May 30, 2015 Mt Etinde is a volcano situated on the southwestern flank of of leucitites...eruptions are dated at 0-65 Ma euhedral to anhedral nepheline-bearing nephelinites. and took place during the...alkali basalts, are melanephelinites, nephelinites nepheline phenocrysts in a groundmass of titansensu strictp...numerous and varied nephelinites that con- augite, nepheline, leucite, magnetite, perovskite, tain one or more |  | Onuma, Naoki, Ninomiya, Shuji, Nagasawa, Hiroshi (1981) Mineral/groundmass partition coefficients for nepheline, melilite, clinopyroxene and perovskite in melilitenepheline basalt, Nyiragongo, Zaire. GEOCHEMICAL JOURNAL, 15 (4) 221-228 doi:10.2343/geochemj.15.221 | Journal (article/letter/editorial) | | clinopyroxene nepheline coefficients for nepheline, perovskite in melilite and basalt, Nyiragongo, Zaire...structure basalt, control" for nepheline-, Nyiragongo volcano, mechanism. melilite and perovskite...partition coefficients are least available for nepheline, melilite and perovskite which are important phases...in alkali rocks The diagrams of a melilite-nepheline ber of divalent elements. This report is to present...partition coefficient versus ionic radius diagrams of nepheline, melilite, clinopyroxene and perovskite in an |  | | Journal (article/letter/editorial) | | is recorded in the western branch of the EARS at Kivu during this time. In contrast, the Early Rift Development...distinct from xenolith suites recovered further north. Lee lP and Rudnick (1999) established a compositionally... from which rifting has of propagated to the north and south during multiple periods in the past 20...Volcanic Province at ca. 17 Ma (Mesko et al., 2014) and Kivu ca. 20 Ma (Pouclet et al., 2016) is coincident with...while the border fault is thought to have formed in Kivu by ca. 10 Ma (Ebinger, 1989a). The formation of |  | | Journal (article/letter/editorial) | | CONTAMINATION IN THE POTASSIC SUITE OF THE KARISlMBI VOLCANO (VIRUNGA, AFRICAN RIFT VALLEY) M. DE M U L D E...contamination in the potassic suite of the Karisimbi Volcano (Virunga, African Rift Valley). In: S. Deutsch...silica-undersaturated volcanics from the Karisimbi volcano (Virunga region, Western African Rift Valley, Rwanda...MIKENOoO LK I MUHAVURA O O GAHING~/Z o NYIRAGONGO RWANDA LAKE KIVU EAST AFRIC~ -ORO-'A.KOL~-t RU~GA t\...African Rift System. Adjacent Toro-Ankole and South Kivu fields are also shown. 1983; Vollmer and Norry |  | | Journal (article/letter/editorial) | | 0024-4937/90/$03.50 e.g. Mt. Cameroon, Cameroon; Mt. Nyiragongo, Zaire; Mt. Erebus, Antarctica. Mount Etna, Sicily...strongly alkaline magmatism is the active volcano Mount Nyiragongo (Zaire) which sustains a lava lake of...release through the magma column, so that the volcano is effectively a gas vent for the local continental...highly glassy) and the nephelinite glass from Nyiragongo. They are clearly not natural D K. BAILEY AND...Bailey, 1985) are produced by the nephelinite from Nyiragongo and this [60 6 5 D K BAILEY A.ND C M. HAMPTON |  | | Journal (article/letter/editorial) | | 40.509–40.866) along with the data of Karisimbi volcano form trends on isotope diagrams towards the EM...part of Virunga, and Muhavura is the easternmost volcano of the province. Visoke, one of the eight main...summit crater lake (Fig.1). Visoke, along with Nyiragongo and Nyamuragira, are the only volcanoes that...(Bagdasaryan et al. 1973), while for the nearby Karisimbi volcano ages range from 30,000 to 120, 000 years (De Mulder...1992, 1998). However, the last eruption of Visoke volcano occurred in 1957, when two small adventive cones |  | | Journal (article/letter/editorial) | | fine-grained leucite-melilite-nephelinite from the Nyiragongo volcano (Zaire). The melilite displays an exceptionally...vacuoles of some lavas of the ~Tyiragongo (Zaire) volcano melilite occurs in tiny crystals in which the exceptionally...types of leucite-melilitenephelinite lavas on Nyiragongo contain open cavities the walls of which are...diameter. The crystals consist of clinopyroxene, nepheline, leucite, melilite, olivine (kirschsteinite),...Directions of the a-axis marked. Specimen VM. 706, Nyiragongo. Scanning electron micrograph. • 100 Fig. 2. |
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