Controle structural du volcanisme indonesien (Sumatra, Java-Bali); application et critique de la methode de Nakamura

Bahar, Ida Baizura; Girod, M.

doi:10.2113/gssgfbull.s7-xxv.4.609

Cited by 14 publications

(5 citation statements)

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“…A high-K, calc-alkaline suite of whole-rock compositions has been identified in recent Merapi volcanic rocks (51900 14 C years BP; Bahar, 1984;del Marmol, 1989;Hammer et al, 2000;Gertisser & Keller, 2003a, 2003b. These samples display a relatively restricted spread in whole-rock isotope ratios, providing evidence for source contamination and minimal interaction with the upper crust (Gertisser & Keller, 2003a).…”

Section: G E O L O G I C a L B Ac Kg Ro U N Dmentioning

confidence: 99%

Carbonate Assimilation at Merapi Volcano, Java, Indonesia: Insights from Crystal Isotope Stratigraphy

Chadwick

Troll

Ginibre

et al. 2007

Journal of Petrology

138

137

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Recent basaltic andesite lavas from Merapi volcano contain abundant, complexly zoned, plagioclase phenocrysts, analysed here for their petrographic textures, major element composition and Sr isotope composition. Anorthite (An) content in individual crystals can vary by as much as 55 mol% (An 40^95 ) across internal resorption surfaces with a negative correlation between high An mol% (470), MgO wt% and FeO wt%. In situ Sr isotope analyses of zoned plagioclase phenocrysts show that the 87 Sr/ 86 Sr ratios of individual zones range from 0Á70568 to 0Á70627.The upper end of this range is notably more radiogenic than the host basaltic andesite whole-rocks (50Á70574). Crystal zones with the highest An content have the highest 87 Sr/ 86 Sr values, requiring a source or melt with elevated radiogenic Sr, rich in Ca and with lower Mg and Fe. Recent Merapi eruptive rocks contain abundant xenoliths, including metamorphosed volcanoclastic sediment and carbonate country rock (calc-silicate skarns) analysed here for petrographic textures, mineralogy, major element composition and Sr isotope composition. The xenoliths contain extremely calcic plagioclase (up to An 100 ) and have whole-rock 87 Sr/ 86 Sr ratios of 0Á70584 to 0Á70786.The presence of these xenoliths and their mineralogy and geochemistry, coupled with the 87 Sr/ 86 Sr ratios observed in different zones of individual phenocrysts, indicate that magma^crust interaction at Merapi is potentially more significant than previously thought, as numerous crystal cores in the phenocrysts appear to be inherited from a metamorphosed sedimentary crustal source. This has potentially significant consequences for geochemical mass-balance calculations, volatile saturation and flux and eruptive behaviour at Merapi and similar island arc volcanic systems elsewhere.

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Section: G E O L O G I C a L B Ac Kg Ro U N Dmentioning

confidence: 99%

Carbonate Assimilation at Merapi Volcano, Java, Indonesia: Insights from Crystal Isotope Stratigraphy

Chadwick

Troll

Ginibre

et al. 2007

Journal of Petrology

138

137

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“…More recently, many structural geologists have recognized from strong field evidence that some magma intrusions have occurred directly along coeval regional strike‐slip faults (Jacques and Reavy, 1994; Johnston, 1999; Olivier et al ., 1999) or associated with block‐rotation along strike‐slip faults (Marra, 2001). At the same time, transcurrent tectonics guiding the location of volcanic centres has been assessed based on strike‐slip faults aligned with, or close to, coeval volcanoes (DeBeoer et al ., 1980; Bahar and Girod, 1983; Harmand and Moukadiri, 1986; Kozhurin, 1990; Tibaldi, 1992; Marinoni and Pasquarè, 1994; Lavenu and Cembrano, 1999). However, detailed analyses of the structures affecting volcanic edifices in basement strike‐slip fault zones indicate that the strain field can rotate from the basement to the cone summit (Lagmay et al ., 2000; Tibaldi and Romero, 2000).…”

Section: Introductionmentioning

confidence: 97%

Do transcurrent faults guide volcano growth? The case of NW Bicol Volcanic Arc, Luzon, Philippines

Pasquarè

Tibaldi

2003

Terra Nova

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This paper shows that although volcanoes can be aligned along transcurrent faults, their growth can in reality be controlled by secondary structures that have a different orientation and kinematics. Assessing the relationships between local structures and volcano growth can be very useful for the evaluation of volcanic hazards and for economic purposes such as geothermal and hydrogeological exploration. In the north‐western Bicol Volcanic Arc (Luzon, Philippines) the Quaternary Labo and Caayunan volcanoes are aligned with the NW‐striking transcurrent Philippine Fault System. They are exceptional examples of composite volcanoes mostly comprising lava domes, where regional tectonic structures and hydraulic radial fracturing have alternated to control volcano growth. Field data and analogue modelling demonstrate that apical depressions affecting the domes reflect the geometry of magma‐feeding fractures. These data, together with alignments of domes and hot springs and other structural information, suggest that magma rose at depth along the NW‐striking transcurrent faults, but that in the uppermost crust magma rose along NE‐striking fractures parallel to the greatest principal stress.

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“…At the surface and through time, the growth or destruction of a volcano is influenced by the volcano-tectonic setting of the region. Studies looking at the influence of regional stress on the direction of sector-collapse and debris-avalanche amphitheater opening have been done for Southeast Asian volcanoes in tectonic settings dominated by strike-slip faults, particularly those in the Philippines, by Lagmay and Valdivia (2006), Japan by Ui et al (1986), and Indonesia by Bahar and Girod (1983), which showed that the opening direction of such features is at an acute angle relative to the regional maximum horizontal stress. Their results are in disagreement with earlier models by Moriya (1980), Siebert (1984), and Nakamura (1977), which show volcano openings perpendicular to the maximum horizontal stress being more prevalent in extensional regions (Tibaldi, 1995), where tabular conduits and dikes that propagate along normal faults promote collapses perpendicular to the regional maximum horizontal stress.…”

Section: Introductionmentioning

confidence: 99%

Tectonic Geomorphology and Volcano-Tectonic Interaction in the Eastern Boundary of the Southern Cascades (Hat Creek Graben Region), California, USA

Paguican

Bursik

2016

Front. Earth Sci.

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The eastern boundary of the Southern Cascades (Hat Creek Graben region), California, USA, is an extensively faulted volcanic corridor between the Cascade Range and Modoc Plateau. The morphology of the region is a result of plate motions associated with different tectonic provinces, faulting, and recurring volcanic activity, making it an ideal place to study the interrelationship between tectonics, volcanoes, and geomorphology. We use the morphometry and spatial distribution of volcanoes and their interaction with regional structures to understand how long term regional deformation can affect volcano evolution. A database of volcanic centers and structures was created from interpretations of digital elevation models. Volcanic centers were classified by morphological type into cones, sub-cones, shields and massifs. A second classification by height separated the larger and smaller edifices, and revealed an evolutionary trend. Poisson Nearest Neighbor analysis showed that bigger volcanoes are spatially dispersed while smaller ones are clustered. Using volcano centroid locations, about 90 lineaments consisting of at least three centers within 6 km of one another were found, revealing that preferential north-northwest directed pathways control the transport of magma from the source to the surface, consistent with the strikes of the major fault systems. Most of the volcano crater and collapse scar openings are perpendicular to the north northwest-directed maximum horizontal stress, expected for extensional environments with dominant normal faulting. Early in the history of a volcano or volcano cluster, melt propagates to the surface using the easiest and most efficient pathway, mostly controlled by the pre-existing normal faults and near-surface stress fields, as indicated by the pervasive vent alignments. Volcano growth continues to be dependent on the regional structures as indicated by the opening directions, suggesting structural control on the growth of the volcanic edifices. The results present a particularly well-defined case in which extension of a volcanic region is accommodated mostly by faulting, and only partly by intrusion to form volcanoes. This is attributed to a low magma supply rate.

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Controle structural du volcanisme indonesien (Sumatra, Java-Bali); application et critique de la methode de Nakamura

Cited by 14 publications

References 0 publications

Carbonate Assimilation at Merapi Volcano, Java, Indonesia: Insights from Crystal Isotope Stratigraphy

Carbonate Assimilation at Merapi Volcano, Java, Indonesia: Insights from Crystal Isotope Stratigraphy

Do transcurrent faults guide volcano growth? The case of NW Bicol Volcanic Arc, Luzon, Philippines

Tectonic Geomorphology and Volcano-Tectonic Interaction in the Eastern Boundary of the Southern Cascades (Hat Creek Graben Region), California, USA

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