Chapter 3 The Use of Lithic Clast Distributions in Pyroclastic Deposits to Understand Pre- and Syn-Caldera Collapse Processes: A Case Study of the Abrigo Ignimbrite, Tenerife, Canary Islands

Pittari, Adrian; Fernand, Raymond Alexander; Wolff, J. A.; Nichols, Holly; Larson, Peter B.; Martı́, Joan

doi:10.1016/s1871-644x(07)00003-4

Cited by 30 publications

(26 citation statements)

References 124 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…When the Cañadas edifice was active, this zone accumulated most of the intrusions of deeper mafic magma in the central part the island due to the shadow effect that phonolitic chambers exerted on more deeper magma avoiding them to reach the surface at that zone (Martí and Gudmundsson 2000). In consequence, most of mafic magmas intruding below the shallow phonolitic systems crystallized there forming dense bodies of gabros, as is testified by high gravimetric positive anomalies (Ablay and Kearey 2000;Gottsmann et al 2008) and the present gabroid xenoliths in some Las Cañadas caldera forming pyroclastic deposits (Martí et al 1994;Pittari et al 2008). The same area seems to be the site today for the accumulation of deeper magmas that then differentiate and evolve into the phonolites that feed Teide-Pico Viejo eruptions, as is indicated by experimental petrology data (Andújar et al 2010).…”

Section: Las Cañ Adas-teide-pico Viejo Complex Attenuation Structurementioning

confidence: 89%

3D Attenuation Tomography of the Volcanic Island of Tenerife (Canary Islands)

et al. 2015

Self Cite

View full text Add to dashboard Cite

This paper shows a new multidisciplinary interpretation approach to the internal structure of Tenerife Island. The central core of this work is the determination of the three-dimensional attenuation structure of the region using P-waves and the coda normalization method. This study has been performed using 45,303 seismograms recorded at 85 seismic stations from an active experiment (air gun shots) conducted in January 2007. The interpretation of these new results is done combining the new images with previous studies performed in the area such as seismic velocity tomography, magnetic structure, magnetotelluric surveys or gravimetric models. Our new 3D images indicate the presence of seismic attenuation contrasts, with areas of high and low seismic attenuation patterns. High seismic attenuation zones are observed both in shallow and in deeper areas. The shallowest area of Las Cañadas caldera complex (1-3 km thick) is dominated by high attenuation behavior, and it is interpreted as the combined effect of sedimentary and volcanoclastic deposits, multifracture systems and the presence of shallow aquifers. At the same time, the deeper analyzed area, more than 8 km below sea level, is dominated by a high attenuation pattern, and it is interpreted as the consequence of the effect of hightemperature rocks in the crustal-mantle boundary. This interpretation is compatible and confirmed by previous models that indicate the presence of underplating magma in this region. On the contrary, some low attenuation bodies and structures have been identified at different depths. A deep low attenuation central body is interpreted as the original central structure associated with the early stage of Tenerife Island. At shallower depths, some low attenuation bodies are compatible with old intermediate magmatic chambers postulated by petrological studies. Finally, in the north of the island (La Orotava valley) we can interpret the low attenuation structure as the headwall of this valley, supporting the idea that Las Cañadas caldera and this valley resulted from two different destructive processes.

show abstract

Section: Las Cañ Adas-teide-pico Viejo Complex Attenuation Structurementioning

confidence: 89%

3D Attenuation Tomography of the Volcanic Island of Tenerife (Canary Islands)

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…In this case, it is interpreted that these calderas start forming since the beginning of the eruption without needing (significant) decompression of the magma chamber (Gudmundsson et al, 1997;Martí et al, 2009). Examples of this type of caldera are La Pacana (e.g., Gardeweg and Ramirez, 1987), Cerro Galán (Folkes et al, 2011), Aguas Calientes (Petrinovic et al, 2010); El Abrigo (Pittari et al, 2008), Bolaños graben caldera (Aguirre-Díaz et al, 2008).…”

Section: Tectonic Settings Of Lcfes and Eruption Conditionsmentioning

confidence: 99%

Stress Field Control during Large Caldera-Forming Eruptions

Costa

Martı́

2016

Front. Earth Sci.

View full text Add to dashboard Cite

Crustal stress field can have a significant influence on the way magma is channeled through the crust and erupted explosively at the surface. Large Caldera Forming Eruptions (LCFEs) can erupt hundreds to thousands of cubic kilometers of magma in a relatively short time along fissures under the control of a far-field extensional stress. The associated eruption intensities are estimated in the range 10 9 -10 11 kg/s. We analyse syn-eruptive dynamics of LCFEs, by simulating numerically explosive flow of magma through a shallow dyke conduit connected to a shallow magma (3-5 km deep) chamber that in turn is fed by a deeper magma reservoir (>∼10 km deep), both under the action of an extensional far-field stress. Results indicate that huge amounts of high viscosity silicic magma ( 10 7 > Pa s) can be erupted over timescales of a few to several hours. Our study provides answers to outstanding questions relating to the intensity and duration of catastrophic volcanic eruptions in the past. In addition, it presents far-reaching implications for the understanding of dynamics and intensity of large-magnitude volcanic eruptions on Earth and to highlight the necessity of a future research to advance our knowledge of these rare catastrophic events.

show abstract

“…They represent about 6 vol.% of fine to median lapilli in that layer. Their pale yellowish surface coloration suggests possible hydrothermal alteration and might indicate the presence of an effective hydrothermal zone beneath the BMM prior to the explosive eruptions (Pittari et al, 2008).…”

Section: Componentrymentioning

confidence: 99%

Towards the reconstruction of the shallow plumbing system of the Barombi Mbo Maar (Cameroon) Implications for diatreme growth processes of a polygenetic maar volcano

Tchamabé

Ohba

Keresztúri

et al. 2015

Journal of Volcanology and Geothermal Research

View full text Add to dashboard Cite

a b s t r a c tUnderstanding the mechanisms involved in the formation of maars and their diatreme growth processes has been a subject of contention. While there is no direct evidence of the presence of diatremes beneath most of the young maars, their existence is inferred based on the amount and type of country rocks excavated at different depths and deposited as pyroclastic ejecta around their craters. Properly tracing fragmented country rocks in ejecta to interpret their depths of origin and thus the depths of phreatomagmatic explosions require good and detailed information on the substrate geology that is generally lacking at many maars. As an alternative, this paper explores the role of juvenile components in deposits of a maar for understanding the cratering and growth of diatremes during maar-forming eruptions. Based on field investigations, pyroclast distribution, componentry and grain morphology examinations this study reports on the eruptive mechanisms that led to the formation of the Barombi Mbo Maar (BMM), a polygenetic maar volcano in Cameroon. The BMM consists of three diatremes that formed during distinct eruptive events and coalesced to produce an "amalgamated maar-diatreme". Two end-member types of eruption styles from the "dry" magmatic to the "wet" phreatomagmatic explosions governed the formation of the maar. In total, a minimum of~0.0658 km 3 of magma (Dense Rock Equivalent corrected) was ejected based on calculation by applying interpolation techniques on digital elevation models obtained from SRTM30m data corrected by rock textural data collected from the field. The distribution of juvenile clasts throughout the stratigraphic sequence suggests a complex subsurface eruptive process, which originated probably within the uppermost part of the diatreme. From the distribution and morphology of juvenile clasts in the deposits, it is inferred that cratering and country rock excavation during the growth of each of the small diatremes developed mainly from shallow level explosions, sometimes with lateral and vertical variations in the position of the explosion loci. A prospective juvenile-based conceptual model is proposed for the formation of the BMM. The model suggests that, during maar-forming eruptions, explosions taking place at a deeper position might entrain extensive amount of lithics from the mostly lithic-dominated upper crater infill to deposit juvenile-poor (b10 vol.%) tephra beds. Layers with a juvenile content of 10-60 vol.%, for example, might result from deep to shallow-seated explosions, with a common entrainment of lithics from the crater infill region, and with much of the remobilized tephra being transported to the ejecta ring sequence. In contrast, explosions occurring at shallower positions will produce mainly juvenile-rich beds (juvenile N 90 vol.%).

show abstract

Chapter 3 The Use of Lithic Clast Distributions in Pyroclastic Deposits to Understand Pre- and Syn-Caldera Collapse Processes: A Case Study of the Abrigo Ignimbrite, Tenerife, Canary Islands

Cited by 30 publications

References 124 publications

3D Attenuation Tomography of the Volcanic Island of Tenerife (Canary Islands)

3D Attenuation Tomography of the Volcanic Island of Tenerife (Canary Islands)

Stress Field Control during Large Caldera-Forming Eruptions

Towards the reconstruction of the shallow plumbing system of the Barombi Mbo Maar (Cameroon) Implications for diatreme growth processes of a polygenetic maar volcano

Contact Info

Product

Resources

About