1-20 OF 67 RESULTS FOR

lapilli

Results shown limited to content with bounding coordinates.
Follow your search
Access your saved searches in your account

Would you like to receive an alert when new items match your search?
Close Modal
Sort by
Journal Article
Journal: Geology
Published: 23 September 2020
Geology (2020)
... lapilli, mud lumps, and vesiculated tuffs; Lorenz, 1974; Fisher and Schmincke, 1984) are used to support interpretations of emplacement by cool (<100 °C), wet pyroclastic surges involving water droplets (e.g., Heiken, 1971; Dellino et al., 1990; Cole, 1991; Sohn, 1996). This implies incomplete...
Series: Geological Society, London, Special Publications
Published: 30 September 2019
DOI: 10.1144/SP477.3
EISBN: 9781786203861
... Abstract Tephra beds are considered to be potential failure planes for submarine landslides. Here, we report on an example of a coarse-ash/lapilli-tuff bed influencing translational slides. The studied mass-transport deposit (MTD) is intercalated in the Pleistocene forearc basin fill exposed...
FIGURES | View All (5)
Journal Article
Journal: GSA Bulletin
Published: 15 April 2019
GSA Bulletin (2019) 131 (9-10): 1537–1554.
... wall-rock clasts (Episode 1) and dominantly scoria (Episode 2; VEI-3) across >65 km 2 southeast of the summit. Dense 12 cm blocks of Episode 1 fell 8–10 km from the summit vent, and 2–4 cm lithic lapilli reached the coastline, 17 km from the vent. The Episode 2 deposit is chemically zoned...
FIGURES | View All (17)
Journal Article
Journal: Geology
Published: 08 January 2019
Geology (2019) 47 (2): 179–182.
... or accretions. To investigate both mechanisms, we analyzed ash-encased lapilli from the Surtseyan eruptions of Capelinhos (Azores, 1957–1958) and Hunga Tonga–Hunga Ha’apai (Tonga, 2014–2015) using X-ray computed microtomography and electron microscopy. We discovered pyroclasts that were not coated, sensu...
FIGURES
Journal Article
Published: 09 March 2016
Journal of the Geological Society (2016) 173 (4): 701–710.
... deposits resulted from phreatomagmatic eruptive phases of the Blue Lake East and the Valley Lake maar craters. The facies descriptions of the two massive, poorly sorted lapilli tuff and tuff breccia deposits are given. Low-grade carbonized wood fragments in the deposits mark low emplacement temperatures...
FIGURES | View All (8)
Journal Article
Journal: Geology
Published: 01 March 2016
Geology (2016) 44 (3): 195–198.
... in lapilli—support a classical model that describes Surtseyan volcanism as being driven by mingling of magma and water-saturated slurry in periodically flooded vents. We use textures, eruption observations, and basic thermodynamics to expand the magma-slurry model and relate it directly to the vapor dynamics...
FIGURES | View All (4)
Journal Article
Journal: GSA Bulletin
Published: 01 September 2015
GSA Bulletin (2015) 127 (9-10): 1437–1452.
... and Houghton (2006) . Among volcaniclastic rocks the terms tuff, lapilli tuff, tuff breccia, and breccia refer to grain size in ascending order, from ash to lapilli to blocks and bombs. Volcaniclastic rocks are lithified deposits of fragments produced and/or transported during the course of a volcanic eruption...
FIGURES | View All (9)
Journal Article
Published: 06 February 2015
Journal of the Geological Society (2015) 172 (3): 287–293.
... deposit that we propose was formed by a dilute pyroclastic density current; pumice flow deposits; and a proximal lapilli and block fallout lobe. The inclined nature of the explosion is attributed to the asymmetric geometry around the vent. The explosion-derived pyroclastic density currents had notably...
FIGURES | View All (7)
Journal Article
Journal: Geosphere
Published: 01 October 2014
Geosphere (2014) 10 (5): 998–1019.
.... Geological and structural map of Lemptégy; light detection and ranging (LiDAR) image generated by S. Petit. The Lemptégy 1 deposit is predominantly an agglomerate deposit, composed of welded or compacted spatter, lapilli, and bombs that are poorly layered or graded, with no clear units being...
FIGURES | View All (15)
Journal Article
Published: 15 September 2014
Journal of the Geological Society (2014) 171 (6): 765–778.
...; Fig. 4 ) shows a continuous change of laminated poorly sorted medium-thick (10–30 cm) beds, from fine to coarse vesiculated lapilli-sized clasts with accidental lithic fragments (syn-caldera ignimbrites and lava flows). This deposit suddenly changes to poorly sorted, very thick (>100 cm) lithic...
FIGURES | View All (8)
Journal Article
Journal: GSA Bulletin
Published: 01 November 2012
GSA Bulletin (2012) 124 (11-12): 1793–1809.
... zoning in the ignimbrite is defined by vertical variations in the relative abundance of rhyodacitic (69–71 wt% SiO 2 ) and andesitic (54–63 wt% SiO 2 ) pumice lapilli: Lower parts are dominated by rhyodacite and pass gradationally up into a central part with andesitic and rhyodacite pumice...
FIGURES | View All (15)
Journal Article
Published: 01 September 2012
South African Journal of Geology (2012) 115 (3): 345–368.
...) is interbedded with the carbonaceous shale and sandstone. The FPR, which contains altered relicts of glass particles and possibly accretionary lapilli spheres, is interpreted to be the leached and ferruginated product of coarse-grained vitric lithic lapilli tuff and tuff, emplaced on an active swamp surface...
FIGURES | View All (26)
Journal Article
Journal: Geology
Published: 01 June 2012
Geology (2012) 40 (6): 563–566.
... derived from distinctive sources that reflect tectonic processes starting, then temporarily stopping, the 27 ka Oruanui supereruption (530 km 3 magma; Taupo, New Zealand). Subordinate (3%–16%) biotite-bearing pumice lapilli occur in fall deposits from phases 1 and 2 (of 10) among the biotite-free “normal...
FIGURES | View All (4)
Journal Article
Journal: Geology
Published: 01 April 2012
Geology (2012) 40 (4): 355–358.
... to centuries required for similar processes to occur in lava flows or magma chambers, and that it occurs within the short time scales that characterize explosive fragmentation of basaltic melt. IVEs examined here are in lapilli from three different deposits, two from deposits ∼1 km below sea level at Loihi...
FIGURES
Journal Article
Published: 01 August 2011
European Journal of Mineralogy (2011) 23 (4): 499–517.
.... Lapilli are strongly vesicular and crystal-poor, similar to other “ golden ” pumices. Modal proportions include 89 vol% glass, 8 vol% clinopyroxene, 1–2 vol% olivine and 1–2 vol% plagioclase. Plagioclase is represented by reacted crystals coming from the shallow resident magma and incorporated...
FIGURES | View All (8)
Series: GSA Special Papers
Published: 01 June 2011
DOI: 10.1130/2011.2478(11)
... Volcaniclastic carbonatites in southeast Zambia contain dolomitic melt lapilli, in which high-Cr chromite phenocrysts indicate direct eruption from the mantle. There are no lava flows. Vent tuffisite, with dolomite lapilli in a matrix of dolomite + iron oxides, provides the least contaminated...
Journal Article
Journal: GSA Bulletin
Published: 01 May 2011
GSA Bulletin (2011) 123 (5-6): 1112–1126.
...M. Thompson Stiegler; Donald R. Lowe; Gary R. Byerly Abstract The 3.5–3.2 Ga Onverwacht Group of the Barberton greenstone belt, South Africa, contains thick sequences of komatiitic tuff, lapilli tuff, and lapillistone representing proximal to distal volcanic settings. Volcaniclastic komatiites...
FIGURES | View All (10)
Series: GSA Special Papers
Published: 01 September 2010
DOI: 10.1130/2010.2465(15)
... and planar-bedded sandstones. Microscopic and geochemical investigations reveal that they are pervasively altered. Many resemble the types of accretionary lapilli recognized from hydroclastic volcanic environments, which implies the presence of significant water at the time of impact. Tookoonooka...
Series: GSA Special Papers
Published: 01 April 2010
DOI: 10.1130/2010.2464(05)
... are presented and discussed here: (1) the new correlation of the former “Sofular Ignimbrite” with the ignimbritic bed of the Sarimaden Tepe Member, and (2) the identification of a widespread pair of Plinian air-fall pumice lapilli beds, tentatively called Güzel Dere Member. It can be correlated with the former...
Journal Article
Journal: Geology
Published: 01 April 2010
Geology (2010) 38 (4): 291–294.
... vesicle textures in lapilli—the physical manifestation of degassing; dissolved volatiles in matrix glasses and olivine-hosted glass inclusions—the geochemical record of ascent and volatile exsolution; and fine ash morphology—the evidence for if and how external water assisted in fragmentation...
FIGURES | View All (4)