Middle America Neogene Explosive Volcanism and Ash Layers: Evidence from the Middle America Trench Transect, Deep Sea Drilling Project Leg 67

Cadet, Jean-Paul; Pouclet, André; Thisse, Y.; Bardintzeff, Jacques-Marie; Azéma, Jacques

doi:10.2973/dsdp.proc.67.115.1982

Cited by 17 publications

(32 citation statements)

References 16 publications

(24 reference statements)

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“…8), glasses from Legs 67 and 84 are distributed in the "T sector" are of middle America Tertiary and Quaternary lavas of Woodruff et al (1979). Intermediate to basic compositions are located in the FeO-rich part where analyses of on-land glasses and vitreous inclusions plot "G sector"; see Cadet et al, 1982).…”

Section: Comparison With On-land Volcanismmentioning

confidence: 99%

“…Petrographic identifications are Bs = basalt; An-B = basalt andesite; An = andesite; De = dacite; Rd = rhyodacite; Rh = rhyolite. SiO 2 typological boundaries are defined by Pecerillo and Taylor (1976) and are slightly modified for Rd, as in Cadet et al, 1982. count times and a defocused beam. In agreement with several authors (cf., Cadet et al, 1981 and1982), we suggest that hydration explains the greatest part of the analytical deficit.…”

Section: Chemical Composition Of Glass Shardsmentioning

confidence: 99%

“…The Pliocene-Pleistocene displays dacites, rhyodacites, and rhyolites from the three groups. Only low-potassic rhyodacites and rhyolites of group A have been analyzed for upper Pleistocene strata, but the other types do exist (cf., Leg 67, Cadet et al, 1982). Recent ash layers include moderately potassic an- upper Oligocene desitic to rhyolitic glasses and a few highly potassic dacites.…”

Section: Chronological Evolutionmentioning

confidence: 99%

“…Leg 67 includes 86 analyses of glasses sampled at four sites on the oceanic plates and the Trench lower slope (Cadet et al, 1982). The samples were analyzed using the BRGM-CNRS Camebax electron-probe microanalyzer in Orleans (France).…”

Section: Comparison With Leg 67mentioning

confidence: 99%

“…Consequently, there is a displacement of AB and BC limits on the SiO 2 /K 2 O diagram used in the Leg 67 chapter (Cadet et al, 1982). However, taking into account this analytical shift, data from the two legs can be combined.…”

Section: Comparison With Leg 67mentioning

confidence: 99%

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Ash Layers from Deep Sea Drilling Project Leg 84: Middle America Trench Transect

Pouclet¹,

Cadet²,

Fujioka³

et al. 1985

Initial Reports of the Deep Sea Drilling Project

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Three Leg 84 sites provided a good record of explosive volcanism onshore (in Central America). Ash layers and many ashy pods are interbedded in Recent to Oligocene strata. Evidence of the main periods of activity was noted in Recent to upper Pleistocene, Pliocene-Pleistocene, lower Pliocene to upper Miocene, lower Miocene, and upper Oligocene. Noticeable traces of older volcanism were found in upper Eocene strata.The chemical analyses of glass shards show a dacitic to rhyolitic composition with a low to moderate calc-alkalinity. A preliminary distinction of samples in three geochemical groups according to their K 2 O/SiO 2 contents is done to test a magmatic evolution. Comparisons are made with Leg 67 and on-land data.

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Section: Comparison With On-land Volcanismmentioning

confidence: 99%

Section: Chemical Composition Of Glass Shardsmentioning

confidence: 99%

Section: Chronological Evolutionmentioning

confidence: 99%

Section: Comparison With Leg 67mentioning

confidence: 99%

Section: Comparison With Leg 67mentioning

confidence: 99%

See 3 more Smart Citations

Ash Layers from Deep Sea Drilling Project Leg 84: Middle America Trench Transect

Pouclet¹,

Cadet²,

Fujioka³

et al. 1985

Initial Reports of the Deep Sea Drilling Project

Self Cite

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A history of violence: magma incubation, timing and tephra distribution of the Los Chocoyos supereruption (Atitlán Caldera, Guatemala)

León

Schindlbeck-Belo

Kutterolf

et al. 2021

J Quaternary Science

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The climactic Los Chocoyos (LCY) eruption from Atitlán caldera (Guatemala) is a key chronostratigraphic marker for the Quaternary period given the extensive distribution of its deposits that reached both the Pacific and Atlantic Oceans. Despite LCY tephra being an important marker horizon, a radioisotopic age for this eruption has remained elusive. Using zircon (U-Th)/He geochronology, we present the first radioisotopically determined eruption age for the LCY of 75 ± 2 ka. Additionally, the youngest zircon crystallization 238 U-230 Th rim ages in their respective samples constrain eruption age maxima for two other tephra units that erupted from Atitlán caldera, W-Fall (130 +16 / −14 ka) and I-Fall eruptions (56 +8.2 / −7.7 ka), which under-and overlie LCY tephra, respectively. Moreover, rim and interior zircon dating and glass chemistry suggest that before eruption silicic magma was stored for >80 kyr, with magma accumulation peaking within ca. 35 kyr before the LCY eruption during which the system may have developed into a vertically zoned magma chamber. Based on an updated distribution of LCY pyroclastic deposits, a new conservatively estimated volume of~1220 ± 150 km 3 is obtained (volcanic explosivity index VEI > 8), which confirms the LCY eruption as the first-ever recognized supereruption in Central America.

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Evaluating the tephra input into Pacific Ocean sediments: distribution in space and time

Straub¹,

Schmincke²

1998

Geologische Rundschau

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We studied the volcanic contribution to the global sediment budget in the Pacific Ocean basin. It is the world's oldest (174 m.y.) and largest (≈49% of Earth's surface area) ocean basin and has had a high and continuous tephra influx from intraplate and convergent margin volcanoes through time. Computerized shipboard data from 65 legs of the Deep Sea Drilling Project (DSDP) and the Ocean Drilling Program (ODP) were screened for the presence of volcaniclastic components. Tephra-bearing and tephra-free core sections (standard 1.5-and 0.30-m core catcher sections) were separated, regardless of the mass fraction of tephra present. The percentage of tephra-bearing core sections ("tephra frequency") per site and time span ("age unit") was calculated. The age units were the Quaternary, the subepochs of the Tertiary, and the stages of the Cretaceous. A total of 424 drill sites yielded 1433 usable stratigraphic units. Fifty percent are younger than 13 m.y., corresponding to only approximately 10% of the total interval studied (124.5 m.y.). The percentage of tephra-bearing age units is high throughout (83±6%) and correlates linearly with the total number of age units (R 2 =0.998; n=17). The average tephra frequency (30-50%) fluctuates, because the abundance of age units of different tephra frequency classes (0, 1-33, 34-67, 68-100% tephra frequency) varies with time. This indicates that the Cenozoic increase in tephra production results from increase in volcanicity and not spatial extension of volcanic source areas. The Cenozoic sediments that were recovered are dominated by distal tephra from explosive arc volcanism. Pulses of arc volcanism occurred in the Pliocene-Quaternary (since ≈5 m.y.) and midMiocene (≈12-15 m.y.). However, the record of explosive arc volcanism in Paleogene and Cretaceous sediments was either not drilled or has been destroyed by subduction. Except for the Cretaceous (≈70-110 m.y.) volcanic pulse, intraplate volcanism is poorly represented in the tephra record because the drill sites are outside the proximal range (>500-1000 km) of the sources. Thus, the tephra record drilled contains significant gaps that bias the estimate of tephra volume towards the less voluminous distal deposits. Most of the volcaniclastic volume accumulated by mass wasting as volcaniclastic aprons surrounding ocean island volcanoes. Volcaniclastic production rates range from 10,000 to 41,800 km 3 /m.y. for large intraplate volcanoes and approximately 10-13 km 3 /km arc length per million years for oceanic island arcs. Extrapolation over the lifetime of major Pacific arcs and hotspot chains, combined with a volume estimate of the distal tephra component, indicates a minimum of 9.3×10 6 km 3 of tephra, corresponding to 23 vol.% of the existing Pacific oceanic sediments. At least two thirds of the tephra volume was deposited in the proximal range and at least half of it is derived from intraplate sources. The large proportion of tephra, its composition, and its localized accumulation causes significant spatial and temporal variati...

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Middle America Neogene Explosive Volcanism and Ash Layers: Evidence from the Middle America Trench Transect, Deep Sea Drilling Project Leg 67

Cited by 17 publications

References 16 publications

Ash Layers from Deep Sea Drilling Project Leg 84: Middle America Trench Transect

Ash Layers from Deep Sea Drilling Project Leg 84: Middle America Trench Transect

A history of violence: magma incubation, timing and tephra distribution of the Los Chocoyos supereruption (Atitlán Caldera, Guatemala)

Evaluating the tephra input into Pacific Ocean sediments: distribution in space and time

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