New constraints on the occurrence of Y-3 Upper Pleistocene tephra marker layer in the Tyrrhenian Sea [PDF]
, 2004 : Munno R. & Petrosino P., New constraints on the occurrence of Y-3 Upper Pleistocene tephra layer in the Tyrrhenian Sea. (IT ISSN 0394 – 3356, 2004). A widespread tephra layer, other than the well known Y-5, has been identified in the Upper Pleistocene ...
Petrosino, Paola, Munno, Rosalba
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Holocene record of large explosive eruptions from Chaitén and Michinmahuida Volcanoes, Chile
Andean Geology, 2013 Tephra fall deposits and one large ignimbrite close to Chaitén and Michinmahuida Volcanoes were analyzed for chemistry and radiocarbon dated to correlate the eruptive units and establish the timing of eruptions.
Álvaro Amigo +2 more
doaj +1 more source
Fall-units and Refractive Index Fluctuations of Eniwa-a Tephra Glass, Hokkaido, Japan
The Quaternary Research (Daiyonki-Kenkyu), 2003 恵庭aテフラ(En-a,17ka BP)の火山ガラス屈折率は,試料採取地点によって異なることがある.その原因は,En-aはフォールユニットごとに火山ガラス屈折率が異なるからである.石狩低地帯南部では,En-aに少なくとも3つのフォールユニットが認められる.火山ガラス屈折率は,上位フォールユニットで高い値(n=1.510-1.514),中～下位フォールユニットで低い値(n=1.505-1.510)を示す.また,単一のフォールユニット内であっても,火山ガラス屈折率は層準によって若干異なる.なお,斜方輝石屈折率については,最下位層準でやや高い値(γ=1.713-1.716)を示すほかは,全層準を通じてほぼ一定の値(γ=1.710-1.715)であった.これまで,火山学やテフロクロノロジーの分野では ...
Nakamura, Yugo, Hirakawa, Kazuomi
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Probabilistic tephra fall hazard and risk assessment
, 2008 A key goal of volcanology is accurate, quantitative forecasting of the potential hazard and risk associated with future volcanic events. Such assessments inform decision makers and enable emergency management plans and risk mitigation procedures, such as
Jenkins, S
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Discovery of halloysite books in a ~270,000 year-old buried tephra deposit in northern New Zealand [PDF]
, 2010 As part of a wider study examining the geomechanical properties, especially sensitivity, of sequences of Quaternary pyroclastic and associated deposits and buried soils in the landslide-prone western Bay of Plenty area near Tauranga, eastern North Island,
Lowe, David J. +3 more
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Pre-conference tephra data workshop: Hands-on session II: Tephra excursion, Okareka loop road (29 January 2023) [PDF]
, 2023 General stratigraphy of Okareka Loop Road section. The following units are evident in the sequence from the base upwards: (1) early tephras (Te Rere, 25.1 cal ka; Okareka, 23.5 cal ka) and thin interbedded loess within the remnant top of a small ...
Lowe, David J., Ilanko, Tehnuka
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The density, construction and drag coefficient of electrostatic volcanic ash aggregates. [PDF]
, 2003 Recent laboratory experiments have demonstrated that electrostatic charges generated during the fragmentation of volcanic pumice cause rapid aggregation of the silicate particles produced.
Lane, Steve J. +5 more
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Latin American Journal of Sedimentology and Basin AnalysisThe 1991 explosive eruption of Hudson volcano in Chile ejected about 2.7 km³ (DRE) of basalt and trachyandesite magma as tephra fall. A majority of the fallout occurred from an eruption during the period August 12-15, 1991, producing an extensive deposit
Roberto A. Scasso, Steven Carey
doaj
Rare earth element geochemistry of the Late Quaternary tephra and volcano-clastic sediments from the Pachuca sub-basin, north-eastern Basin of Mexico [PDF]
Geofísica Internacional, 2010 Chondrite normalized REE patterns, fractionations of light (La/Sm), heavy (Gd/Yb) and total (La/Yb) REE and Eu anomalies of the Late Quaternary multi-layer tephra fall deposits and overlying volcano-clastic sediments deposited in the Pachuca sub-basin ...
R. Lozano +4 more
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Unravelling upbuilding pedogenesis in tephra and loess sequences in New Zealand using tephrochronology [PDF]
, 2010 The genesis of soils developed in either tephra or loess on stable sites differs markedly from that of soils developed on rock because classical topdown processes operate in conjuction with geological processes whereby material is added to the land ...
Lowe, David J., Tonkin, Philip J.
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