Sugarloaf Mountain Tephra — A Pleistocene Rhyolitic Deposit of Base-Surge Origin in Northern Arizona

Sheridan, M. F.; Updike, Randall G.

doi:10.1130/0016-7606(1975)86<571:smtapr>2.0.co;2

Cited by 74 publications

(32 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Tuff rings and tuff cones of dacitic to rhyolitic composition are recognized throughout the world (Sheridan and Updike 1975;Heiken and Wohletz 1987;Brooker et al 1993;Austin-Erickson 2007;Carrasco-Núñez et al 2007) though first-hand scientific observation of this type of eruption is notably rare. This paper describes Cerro Pinto, a Pleistocene, rhyolite, tuff ring-dome complex that has the volume and chemical signature characteristic of simple, monogenetic, rhyolite domes, but conflictingly, has variations in eruptive styles, such as vent migration, explosive reactivation, and dome collapse that are more commonly associated with polygenetic volcanism.…”

Section: Introductionmentioning

confidence: 98%

Evolution of tuff ring-dome complex: the case study of Cerro Pinto, eastern Trans-Mexican Volcanic Belt

2010

View full text Add to dashboard Cite

Cerro Pinto is a Pleistocene rhyolite tuff ringdome complex located in the eastern Trans-Mexican Volcanic Belt. The complex is composed of four tuff rings and four domes that were emplaced in three eruptive stages marked by changes in vent location and eruptive character. During Stage I, vent clearing produced a 1.5-km-diameter tuff ring that was then followed by emplacement of two domes of approximately 0.2 km 3 each. With no apparent hiatus in activity, Stage II began with the explosive formation of a tuff ring~2 km in diameter adjacent to and north of the earlier ring. Subsequent Stage II eruptions produced two smaller tuff rings within the northern tuff ring as well as a small dome that was mostly destroyed by explosions during its growth. Stage III involved the emplacement of a 0.04 km 3 dome within the southern tuff ring. Cerro Pinto's eruptive history includes sequences that follow simple rhyolite-dome models, in which a pyroclastic phase is followed immediately by effusive dome emplacement. Some aspects of the eruption, however, such as the explosive reactivation of the system and explosive dome destruction, are more complex. These events are commonly associated with polygenetic structures, such as stratovolcanoes or calderas, in which multiple pulses of magma initiate reactivation. A comparison of major and trace element geochemistry with nearby Pleistocene silicic centers does not show indication of any co-genetic relationship, suggesting that Cerro Pinto was produced by a small, isolated magma chamber. The compositional variation of the erupted material at Cerro Pinto is minimal, suggesting that there were not multiple pulses of magma responsible for the complex behavior of the volcano and that the volcanic system was formed in a short time period. The variety of eruptive style observed at Cerro Pinto reflects the influence of quickly exhaustible water sources on a short-lived eruption. The rising magma encountered small amounts of groundwater that initiated eruption phases. Once a critical magma:water ratio was exceeded, the eruptions became dry and sub-plinian to plinian. The primary characteristic of Cerro Pinto is the predominance of fall deposits, suggesting that the level at which rising magma encountered water was deep enough to allow substantial fragmentation after the water source was exhausted. Isolated rhyolite domes are rare and are not currently viewed as prominent volcanic hazards, but the evolution of Cerro Pinto demonstrates that individual domes may have complex cycles, and such complexity must be taken into account when making hazard risk assessments.

show abstract

Section: Introductionmentioning

confidence: 98%

Evolution of tuff ring-dome complex: the case study of Cerro Pinto, eastern Trans-Mexican Volcanic Belt

2010

View full text Add to dashboard Cite

show abstract

“…Within 10-15 km of the vent, the clouds essentially dissipated their destructive power and lost their coarser grains by gravitational settling, thus evolving from powerful dune-forming to massive and planar bed-forming fine-ash surge deposits ( Fig. 2) (19,20). Turbulent damping, steam condensation, and particle aggregation caused the cloud to deflate rapidly and deposit ash abruptly within a distance of 15-25 km.…”

Section: Interdisciplinary Field and Laboratory Evidencementioning

confidence: 99%

The Avellino 3780-yr-B.P. catastrophe as a worst-case scenario for a future eruption at Vesuvius

Mastrolorenzo

Petrone

Pappalardo

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

A volcanic catastrophe even more devastating than the famous anno Domini 79 Pompeii eruption occurred during the Old Bronze Age at Vesuvius. The 3780-yr-B.P. Avellino plinian eruption produced an early violent pumice fallout and a late pyroclastic surge sequence that covered the volcano surroundings as far as 25 km away, burying land and villages. Here we present the reconstruction of this prehistoric catastrophe and its impact on the Bronze Age culture in Campania, drawn from an interdisciplinary volcanological and archaeoanthropological study. Evidence shows that a sudden, en masse evacuation of thousands of people occurred at the beginning of the eruption, before the last destructive plinian column collapse. Most of the fugitives likely survived, but the desertification of the total habitat due to the huge eruption size caused a social-demographic collapse and the abandonment of the entire area for centuries. Because an event of this scale is capable of devastating a broad territory that includes the present metropolitan district of Naples, it should be considered as a reference for the worst eruptive scenario at Vesuvius.archeoanthropology ͉ Bronze Age ͉ volcanic catastrophe ͉ volcanology P linian eruptions are highly destructive volcanic events that produce severe and long-lasting damage over thousands of squared kilometers of the territory surrounding volcanoes (1-4). Studies of the occurrence of plinian eruptions in densely populated areas reveal that most of the people who lived in the affected zones survived (3, 5). However, because of the habitat devastation and their inability to rehabilitate their homeland (5-7), many victims suffer social-economic crises and health status decline (3,5,8). Strong eruption precursors commonly alert the people days to months before the cataclysmic event; in the early phases of a plinian eruption, the slow escalation of the phenomena could allow them to escape from the volcano and flee beyond the lapilli fallout zone. The success of the evacuation depends mainly on its timeliness, because the early phase of a plinian eruption may not be lethal, even close to the volcano (2). Nevertheless, in most cases, the emplacement of billions of cubic meters of ash and lapilli in the form of a continuous blanket from decimeters to meters thick retards or prevents the recovery of the social-economical structure for decades to centuries, even tens of kilometers away from the vent (3, 9, 10).An extraordinary case that sheds light on such catastrophic consequences of an eruption is the Bronze Age Avellino plinian event at Vesuvius, dated by 14 C to Ϸ3780 yr B.P. (2, 10, 11). The eruption produced Ϸ4 km 3 of phonolitic ash and lapilli, a large subaqueous debris-flow avalanch in the gulf of Naples (12), and was even reported to have caused a global climatic disturbance (13). This event started with a moderate-sized explosive phase followed by a plinian column that in a few hours rose to 36 km in the stratosphere and, driven by westerly winds, produced a lapilli fallout covering thousands...

show abstract

“…Sheridan and Updike 1975) to voluminous phreatoplinian eruptions (Self and Sparks 1978). Large-scale phreatomagmatic eruptions commonly fluctuate between both plinian and phreatoplinian end members, producing a wide spectrum of deposit types (e.g.…”

Section: Silicic Phreatomagmatismmentioning

confidence: 99%

Silicic phreatomagmatism in the Snake River Plain: the Deadeye Member

Ellis

Branney²

2010

Bull Volcanol

View full text Add to dashboard Cite

Non-welded rhyolitic pyroclastic units in the central Snake River Plain are interbedded with the much better exposed, large-volume 'Snake-River type' rheomorphic welded rhyolitic ignimbrites and rhyolite lavas. We document one such unit to investigate why it is so different from the interbedded welded ignimbrites. The newly recognised Deadeye Member of southern Idaho is a soilbounded eruption-unit that comprises ashfall layers and a 4-m-thick ignimbrite that extends for >35 km. The ignimbrite is non-welded, lithic-clast poor and varies from massive to diffuse low-angle cross-bedded. It contains abundant angular clasts of non-vesicular black glass, and upper parts contain accretionary lapilli. The ashfall layers above it contain coated ash pellets and ash clumps, which record moist aggregation of fine ash. The magmas of the Deadeye eruption were closely similar in composition and temperature to those that generated the intensely welded rheomorphic ignimbrites of the central Snake River Plain. We infer that the marked contrast in physical appearance of the Deadeye ignimbrite compared to the other, more typical Snake-River-type welded ignimbrites was the result of emplacement at relatively low temperatures during an eruption in a lacustrine environment. Magmatic volatiledriven fragmentation of the rhyolitic magma was influenced by interaction with lake water that also led to cooling. The Deadeye Member is the first-recorded example of explosive silicic phreatomagmatism in the central Snake River Plain.

show abstract

Sugarloaf Mountain Tephra — A Pleistocene Rhyolitic Deposit of Base-Surge Origin in Northern Arizona

Cited by 74 publications

References 0 publications

Evolution of tuff ring-dome complex: the case study of Cerro Pinto, eastern Trans-Mexican Volcanic Belt

Evolution of tuff ring-dome complex: the case study of Cerro Pinto, eastern Trans-Mexican Volcanic Belt

The Avellino 3780-yr-B.P. catastrophe as a worst-case scenario for a future eruption at Vesuvius

Silicic phreatomagmatism in the Snake River Plain: the Deadeye Member

Contact Info

Product

Resources

About