1-20 OF 72 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 July 2021
Geology (2021) 49 (11): 1307–1311.
... and expansion. New textural observations of sub-Plinian and Plinian pumice lapilli reveal that some primary products of magma fragmentation survive by sintering together within seconds of magma break-up. Their size distributions reflect the energetics of fragmentation, consistent with products of rapid...
FIGURES | View All (4)
Journal Article
Published: 01 December 2020
Rocky Mountain Geology (2020) 55 (2): 75–89.
... Ma for zircons extracted from a recently recognized dacite lapilli ash-fall tuff near the base of the synorogenic Iron Springs Formation. We propose the name “Three Peaks Tuff Member” for this unit, and identify a type stratigraphic section on the western flank of the “Three Peaks,” a topographic...
FIGURES | View All (9)
Journal Article
Journal: Geology
Published: 23 September 2020
Geology (2021) 49 (2): 211–215.
... vertical surfaces, steep-sided dune forms, accretionary 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...
FIGURES
Journal Article
Published: 06 August 2020
Canadian Journal of Earth Sciences (2021) 58 (3): 247–267.
... in this study are named using the granulometric terms tuff, lapilli tuff, lapillistone, and tuff breccia of Fisher (1966) . Bedding thickness and type is described using terminology from McPhie et al. (1993) . The term “juvenile”, in this paper, corresponds with “cognate lithics” of Cas and Wright (1987...
FIGURES | View All (13)
Journal Article
Published: 21 April 2020
Geological Magazine (2020) 157 (12): 2021–2032.
... reworked tuffite containing pumice and lithic clasts that petrologically and geochemically resemble those found in KPT unit E tephra, and reworked accretionary lapilli similar to those in KPT unit F. Tuffite is found only downslope from a 375-m-high pass between the Dikeos and Sympetro mountains, which...
FIGURES | View All (10)
Series: Geological Society, London, Special Publications
Published: 30 September 2019
DOI: 10.1144/SP477.3
EISBN: 9781786203861
...Abstract 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...
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.
... 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 distinguishable. The original height of Lemptégy 1...
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
Published: 01 June 2012
Russ. Geol. Geophys. (2012) 53 (6): 535–545.
... might be interpreted as an intensely altered volcanoclastic lapilli tuff of basic and, probably, ultrabasic composition. The tuff occurs within a 100 m thick Ladinian–Carnian volcanosedimentary sequence. It consists mainly of resurgent material: altered lithoclasts (nodules of basic-ultrabasic...
FIGURES | View All (7)
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. Figure 1. Intravesicular extrusions (IVEs) in Loihi tholeiitic lapilli (Hawaii, A–G) and Loihi alkalic (H...
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)