| DOI: | 10.1016/j.gloplacha.2014.10.010
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| 论文题名: | Edifice growth and collapse of the Pliocene Mt. Kenya: Evidence of large scale debris avalanches on a high altitude glaciated volcano |
| 作者: | Schoorl J.M.; Veldkamp A.; Claessens L.; van Gorp W.; Wijbrans J.R.
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| ISSN: | 0921-8388
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| 出版年: | 2014
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| 卷: | 123, 期:PA | | 起始页码: | 44
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| 结束页码: | 54
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| 语种: | 英语
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| 英文关键词: | 40Ar/39Ar geochronology
; Kenya Rift valley
; Lahar
; Mt. Kenya
; Phonolite
; Pliocene
; Volcanic debris avalanche
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| Scopus关键词: | Kenya rift valleys
; Lahar
; Mt. Kenya
; Phonolite
; Pliocene
; Volcanic debris
; altitude
; argon isotope
; Cenozoic
; debris avalanche
; environmental change
; geochronology
; growth
; hominid
; phonolite
; Pliocene
; reconstruction
; uplift
; vegetation structure
; volcano
; Kenya
; Rift Valley
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| 英文摘要: | The cyclic growth and destruction of the Late Cenozoic Stratovolcano Mt. Kenya have been reconstructed for its southeastern segment. At least three major debris avalanche deposits have been reconstructed and dated. The oldest deposits indicate an edifice collapse around 4.9Ma (40Ar/39Ar), followed by a larger event around 4.1Ma (40Ar/39Ar). The last and best preserved debris avalanche deposit, with still some morphological expression covering the whole 1214km2 SE sector, occurred around 2.83Ma (40Ar/39Ar). This very large debris avalanche event must have truncated the whole top of Mt. Kenya. Of the original typical hummocky relief, only local topographical depressions are still best visible and preserved. Using known geometric empirical parameters of the 3 preserved debris-avalanche deposits, the height of the sector collapse is estimated to be in the range of 5100-6500m above the current height of 1000ma.s.l. near the end lobe of the VDA deposits. This demonstrates that Mt. Kenya attained impressive altitudes during its main activity in the Pliocene, being one of the highest mountains in that time and was most probably covered by an ice cap. Correcting for the known net eastward tilting post eruptive uplift of approximately 500m of the Mt. Kenya summit, our reconstruction indicates that an at least 5.6 to 7kma.s.l. high active Mt. Kenya existed in the Pliocene landscape between 5.1 and 2.8Ma. This volcano must have significantly contributed to regional environmental change, by catching rain on its eastern slopes and projecting a rain shadow towards the Kenya Rift valley in the west. The last major edifice collapse event around 2.8Ma coincides with a major change in regional vegetation. This suggests that the truncating of Mt. Kenya may have caused significant changes in the local climate surrounding Mt. Kenya with possible implications for environmental change in the central Kenya Rift valley, the cradle of hominin evolution. © 2014 Elsevier B.V. |
| URL: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84909948287&doi=10.1016%2fj.gloplacha.2014.10.010&partnerID=40&md5=dfe1da9bb3a439bdcb7ac333152b175e
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| Citation statistics: |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/11294
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| Appears in Collections: | 全球变化的国际研究计划
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作者单位: | Soil Geography and Landscape Group, Wageningen University, P.O. Box 47, Wageningen, Netherlands
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| Recommended Citation: | |
Schoorl J.M.,Veldkamp A.,Claessens L.,et al. Edifice growth and collapse of the Pliocene Mt. Kenya: Evidence of large scale debris avalanches on a high altitude glaciated volcano[J],2014-01-01,123(PA).
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