Obstacle Dunes and Obstacle Marks

Living reference work entry
DOI: https://doi.org/10.1007/978-1-4614-9213-9_246-1

Definition

Structures formed by secondary currents which originate when the main flow is deformed by obstacles within the path of the current (either wind, streamflow, or ice). The term obstacle dune is used for aeolian sand accumulations whereas the term “obstacle mark” usually describes fluvial landforms, although it is also used for erosional aeolian features.

Description

Depositional or erosional forms related to topographic obstacles (e.g., mountains, cliffs, mesas, buttes, boulders, or shrubs on Earth) (flow obstruction/sand shadow/current shadow). Obstacle dunes are accumulations of aeolian sand (see also “Ridge in Current Shadow”); obstacle marks form where a current excavates sediment from the front and sides of an obstacle (Allen 1982) (see also “Current Crescent”).

Subtypes

Obstacle dunes (Pye and Tsoar 1990) (Figs. 1, 2 and 3)

Keywords

Vortex Hunt Crest Pier Boulder 
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Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  1. 1.Planetary Science Research GroupEötvös Loránd University, Institute of Geography and Earth SciencesBudapestHungary