DOI: 10.1016/j.gloplacha.2016.08.006
论文题名: Large scale pantelleritic ash flow eruptions during the Late Miocene in central Kenya and evidence for significant environmental impact
作者: Claessens L. ; Veldkamp A. ; Schoorl J.M. ; Wijbrans J.R. ; van Gorp W. ; Macdonald R.
刊名: Global and Planetary Change
ISSN: 0921-8181
出版年: 2016
卷: 145 起始页码: 30
结束页码: 41
语种: 英语
英文关键词: 40Ar/39Ar geochronology
; Ash flow
; Ignimbrite
; Peralkaline rhyolites
; Tuff
; Vitrophyre
Scopus关键词: Deposits
; Geochronology
; Welding
; Ash flow
; Ignimbrites
; Peralkaline rhyolites
; Tuff
; Vitrophyre
; Environmental impact
英文摘要: In the area south-east of Mount Kenya, four previously unrecorded peralkaline rhyolitic (pantelleritic) ash flow tuffs have been located. These predominantly greyish welded and non-welded tuffs form up to 12 m thick units, which are sometimes characterized by a basal vitrophyre. The four flow units yielded 40Ar/39Ar ages ranging from 6.36 to 8.13 Ma, indicating a period of ~ 1.8 Ma of pantelleritic volcanic activity during the Late Miocene in central Kenya. Tentative compositional and age correlations with other known tuff deposits suggest that the pantelleritic tuffs originally covered 40,000 km2 in central Kenya, extending much further than earlier recorded Pliocene tuffs. This newly identified magmatic phase occurred between the phonolitic flood eruptions (16–8 Ma) and the Pliocene tuff eruptions (6–4 Ma). The occurrence of multiple ash flow tuff deposits up to 150 km away from the inferred eruptive center(s) in the central sector of the Kenya Rift, indicates multi-cyclic peralkaline supereruptions during the Late Miocene. By analogy with more recent pantelleritic eruptions, the tuffs are thought to have been sulfur-rich; during eruption, they formed stratospheric aerosols, with significant environmental impact. The timing of the eruptions coincides with the shift towards more savannah-dominated environments in East Africa. © 2016 Elsevier B.V. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84983503425&doi=10.1016%2fj.gloplacha.2016.08.006&partnerID=40&md5=70fe4965a46c8bafbbb4def914207c3d
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/11616
Appears in Collections: 全球变化的国际研究计划 气候变化与战略
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作者单位: Soil Geography and Landscape group, Wageningen University, P.O. Box 47, Wageningen, Netherlands
Recommended Citation:
Claessens L.,Veldkamp A.,Schoorl J.M.,et al. Large scale pantelleritic ash flow eruptions during the Late Miocene in central Kenya and evidence for significant environmental impact[J]. Global and Planetary Change,2016-01-01,145.