Pebble segregation and bed lenticularity in wave‐worked versus alluvial gravel*

Abstract

Two aspects of bedding may permit visual discrimination between wave‐worked and alluvial gravel. Pebbles in gravel worked by waves tend to be better segregated into discrete beds than those in alluvial deposits, and bedding in wave‐worked gravel tends to be more laterally regular, or less lenticular, than that in stream gravel. Pebble segregation and lenticularity were quantitatively analysed in twenty‐five different marine and fluvial deposits of Quaternary or Tertiary age in southwestern Oregon in order to evaluate their use as environmental indicators. The results indicate that these two factors combined provide a visual criterion for discriminating between many gravels of wave‐worked and alluvial origin.

Depositional setting and early diagenesis of the dinosaur eggshell-bearing Aren Fm at Bastus, Late Campanian, south-central Pyrenees

“…Similar structureless deposits have been reported by Leckie (1988) as a common type of facies associated with coarse-grained ripples, and the apparent lack of lamination interpreted as an effect of the poorly sorted nature of the sediment. Coarse-grained ripples occur in modern nearshore deposits in water depths ranging from 3 to 160 m (Clifton, 1973;Leckie, 1988), or below the swash zone (Clifton et al, 1971;Hart and Plint, 1989).…”

Facies analysis, genetic sequences, and paleogeography of the lower part of the Minturn Formation (Middle Pennsylvanian), southeastern Eagle Basin, Colorado

“…The laminae were deposited by suspension clouds generated by incoming waves (Reineck and Singh, 1980). The discrete and laterally continuous beds of granules and pebbles are similar to wave-worked gravels described by Clifton (1973). Erosional set contacts were probably caused by variations in wave depth, velocity, and direction.…”

Precambrian basin-margin fan deposits: Mesoproterozoic Bagalkot Group, India

“…Subfacies E B at the distal section depicts pulsatory transgression of the standing body of water, and the granular lag at its base presumably formed when the standing body of water encroached upon the fan. Laterally discontinuous granular lags within the subfacies are possibly of wave-winnowing origin ( [Clifton, 1973] and [Levell, 1980]). Fig.…”