SEDIMENTOLOGY AND EVENT TIMING OF A CATASTROPHIC VOLCANICLASTIC MASS-FLOW, VOLCAN-HUDSON, SOUTHERN CHILE

被引：68

作者：

BEST, JL

机构：

[1] Department of Earth Sciences, The University, Leeds, LS2 9JT, West Yorkshire

来源：

BULLETIN OF VOLCANOLOGY | 1992年 / 54卷 / 04期

关键词：

D O I：

10.1007/BF00301484

中图分类号：

P [天文学、地球科学];

学科分类号：

07 ;

摘要：

Eruption of Volcan Hudson, Aisen region, Southern Chile on 12 August 1971 melted up to 80% of ice within the 9-km-wide Hudson caldera. Rapid mobilisation of abundant fluvio-glacial sediment within the adjacent Huemules valley led to the generation of a catastrophic mass flow which swept westwards along the valley, eventually entering the fjord some 40 km down-stream. The mass flow, developing from one source and being unaffected by tributary input, was characterised by three events within the flood hydrograph: (1) a precessional flood possibly linked to breakage of an early formed dammed lake; (2) a main mass flow which varied in its rheological behaviour from plug-flow to hyperconcentrated flow; and (3) a recessional flood at the tail of the main flow which diluted towards a concentrated streamflow. The main debris flow displayed characteristics of pulsing, internal segregation/density stratification, significant downstream sediment assimilation, cohesive/frictional freezing with ensuing fluidisation and development of an advancing runout phase. Consideration of these sedimentary characteristics and spatial/temporal flow transformations are used to propose a schematic model of event timing within this catastrophic volcaniclastic flow.

引用

页码：299 / 318

页数：20

共 51 条

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