Abstract: Study of Sand Patterns Resulting from Current Movements

T. F. Tyler

Sand patterns resulting from current movements were studied at the U.S. Geological Survey sedimentation laboratory. The purpose of this study was (1) to observe what factors cause the development and transition of one ripple pattern into another pattern and (2) to observe what ripple bed forms are the resultant of this transition.

The development of sand patterns from water currents appears to be controlled by three primary factors: the quantity of sand available, the flow velocity of the current, and the depth of water covering the sand.

For an offshore profile, the patterns of bed forms developing in plan view from the bar seaward are parallel straight, parallel sinuous, coalescing crescentic, and crescentic.

Small-scale ripple bed forms are compared with large-scale megaripple bed forms and their transition patterns. Large-scale ripple bed forms are compared with large-scale eolian-dune bed forms. Distinctive and characteristic external bed form patterns develop in each situation.

AAPG Search and Discovery Article #90979©1975 AAPG – SEPM Rocky Mountain Sections Annual Meeting, Albuquerque, New Mexico