Ripple marks obviously never appear in sands coarser than 0.
The hardground that was formed on ripple marks served later as the substrate for the colonization of new organisms, for example, the edrioasteroid echinoderm Cyathocystis occurring abundantly in reefs (Fig.
Still, Tanner (1960, 1967) states that morphological features are useless and no real RI can be obtained for flat-topped ripple marks.
3 of the ripple marks in Vasalemma show similarity with the wavecurrent ripples (Tanner 1967; Reineck & Singh 1973).
The sea bottom relief evidently became very differentiated, which caused variation in water flow and the direction of ripple marks.
Ripple marks in the Lower Palaeozoic (Cambrian to Devonian) of Estonia have been described rather briefly on the basis of the wavelength and height.
Kivistunud virgmargid Eiklas [Ancient wave ripple marks at Eikla].
The relation between the size of wave-formed ripple marks, depth of water, and the size of the generating waves.
Late Ordovician ripple marks in Vasalemma quarry, NW Estonia.
Oscillatory ripple marks and the evolution of ancient wave conditions and environments.
Internal structure of wave-formed ripple marks in the nearshore zone.