Book contents
- Frontmatter
- Contents
- List of contributors
- 1 Overview of megaflooding: Earth and Mars
- 2 Channel-scale erosional bedforms in bedrock and in loose granular material: character, processes and implications
- 3 A review of open-channel megaflood depositional landforms on Earth and Mars
- 4 Jökulhlaups in Iceland: sources, release and drainage
- 5 Channeled Scabland morphology
- 6 The morphology and sedimentology of landforms created by subglacial megafloods
- 7 Proglacial megaflooding along the margins of the Laurentide Ice Sheet
- 8 Floods from natural rock-material dams
- 9 Surface morphology and origin of outflow channels in the Valles Marineris region
- 10 Floods from fossae: a review of Amazonian-aged extensional–tectonic megaflood channels on Mars
- 11 Large basin overflow floods on Mars
- 12 Criteria for identifying jökulhlaup deposits in the sedimentary record
- 13 Megaflood sedimentary valley fill: Altai Mountains, Siberia
- 14 Modelling of subaerial jökulhlaups in Iceland
- 15 Jökulhlaups from Kverkfjöll volcano, Iceland: modelling transient hydraulic phenomena
- 16 Dynamics of fluid flow in Martian outflow channels
- Index
- Plate section
- References
13 - Megaflood sedimentary valley fill: Altai Mountains, Siberia
Published online by Cambridge University Press: 04 May 2010
- Frontmatter
- Contents
- List of contributors
- 1 Overview of megaflooding: Earth and Mars
- 2 Channel-scale erosional bedforms in bedrock and in loose granular material: character, processes and implications
- 3 A review of open-channel megaflood depositional landforms on Earth and Mars
- 4 Jökulhlaups in Iceland: sources, release and drainage
- 5 Channeled Scabland morphology
- 6 The morphology and sedimentology of landforms created by subglacial megafloods
- 7 Proglacial megaflooding along the margins of the Laurentide Ice Sheet
- 8 Floods from natural rock-material dams
- 9 Surface morphology and origin of outflow channels in the Valles Marineris region
- 10 Floods from fossae: a review of Amazonian-aged extensional–tectonic megaflood channels on Mars
- 11 Large basin overflow floods on Mars
- 12 Criteria for identifying jökulhlaup deposits in the sedimentary record
- 13 Megaflood sedimentary valley fill: Altai Mountains, Siberia
- 14 Modelling of subaerial jökulhlaups in Iceland
- 15 Jökulhlaups from Kverkfjöll volcano, Iceland: modelling transient hydraulic phenomena
- 16 Dynamics of fluid flow in Martian outflow channels
- Index
- Plate section
- References
Summary
Summary
During the Quaternary, the Altai Mountains of south-central Siberia sustained ice caps and valley glaciers. Glaciers or ice lobes emanating from plateaux blocked the outlet of the Chuja–Kuray intermontane basins and impounded meltwater to form large ice-dammed lakes up to 600 km3 capacity. On occasion the ice dams failed and the lakes emptied catastrophically. The megafloods that resulted were deep, fast-flowing and heavily charged with sand and gravel, the sediment being sourced from the lake basins and also entrained along the course of the floodways. The floods were confined within mountain valleys of the present-day rivers Chuja and Katun but large quantities of sediment were deposited over a distance of more than 70 km from the dam site in tributary river-mouths, re-entrants in the confining valley walls and on the inside of major valley bends. The main depositional units that resulted are giant bars, which blocked the entrances to tributaries and temporarily impeded normal drainage from the tributaries into the main-stem valley such that minor lakes were impounded within the tributaries behind the bars. Fine sediment from the tributaries accumulated in these lakes as local lacustrine units. Later the bars were breached by the tributary flows and the local lakes were drained. Sections of the giant bar sediments and the local lacustrine units are used to describe the nature of the megaflood valley fill, which was deposited primarily during marine isotope stage 2.
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- Chapter
- Information
- Megaflooding on Earth and Mars , pp. 243 - 264Publisher: Cambridge University PressPrint publication year: 2009
References
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