Analysis of Terrestrial Hyperconcentrated Flows and their Deposit

  1. I. Peter Martini2,
  2. Victor R. Baker3 and
  3. Guillermina Garzón4
  1. M. Benvenuti1 and
  2. I. P. Martini2

Published Online: 17 MAR 2009

DOI: 10.1002/9781444304299.ch10

Flood and Megaflood Processes and Deposits: Recent and Ancient Examples

Flood and Megaflood Processes and Deposits: Recent and Ancient Examples

How to Cite

Benvenuti, M. and Martini, I. P. (2002) Analysis of Terrestrial Hyperconcentrated Flows and their Deposit, in Flood and Megaflood Processes and Deposits: Recent and Ancient Examples (eds I. P. Martini, V. R. Baker and G. Garzón), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444304299.ch10

Editor Information

  1. 2

    Department of Land Resource Science, University of Guelph, Guelph, Ontario, Canada

  2. 3

    Department of Hydrology and Water Resources, University of Arizona, Tucson, AZ 85721–0011, USA

  3. 4

    Dpto de Geodinámica, Fac. de Geología, Universidad of Complutense, 28040 Madrid, Spain

Author Information

  1. 1

    Dipartimento di Scienze della Terra, Università di Firenze, Italy

  2. 2

    Department of Land Resource Science, University of Guelph, Guelph, Ontario, Canada

Publication History

  1. Published Online: 17 MAR 2009
  2. Published Print: 10 FEB 2002

ISBN Information

Print ISBN: 9780632064045

Online ISBN: 9781444304299

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Keywords:

  • analysis of terrestrial hyperconcentrated flows and deposits;
  • end-member flows and related deposits;
  • hyperconcentrated flows;
  • hyperconcentrated-flow deposits - case histories from the literature;
  • alluvial-fan setting;
  • fluvial setting;
  • hyperconcentrated-flow deposits - lingering difficulty in recognition

Summary

The term hyperconcentrated flow refers to intermediate states between debris flows and fluid flows, where fluid turbulence remains an important dispersal mechanism of clastic particles. Whereas the end-member flows are fairly well understood, unanimous agreement has not been reached on the subdivision and boundary definition of hyperconcentrated flows, both in meaningful rheological terms and, more so, in terms of the characteristics of their deposits. This paper briefly reviews the main characteristics of hyperconcentrated flows resulting from either suspended-load hyperconcentration or bedload hyperconcentration (traction carpet), and focuses on the analysis of three deposits possibly associated with these flows. The first two deposits formed in ancient, temperate alluvial fans of Pliocene–Pleistocene post-collision basins of the Northern Apennines, Italy, and the third in Upper Pleistocene glacial outwash of Ontario, Canada. The main finding is that geomorphological setting, climate and substrate geology are the prime control for hyperconcentrated flows in terms of frequency, magnitude and rheological properties of the flow. Recognition of hyperconcentrated-flow deposits through facies analysis leads to a better understanding of the developmental dynamics of alluvial sediment succession, and provides powerful information for risk assessment of localities possibly affected by hydrogeological hazards.