...David Franklin Demarest Abstract Measurements of the acute angles of rhomboid ripple marks and their relationship to beach slope are tabulated and discussed. The motions of the backwash and the subsequent run-off are described with special reference to the mode of origin of rhomboid ripple marks...

...John H. Hoyt; Vernon J. Henry Abstract The direction of current flow over the beach surface may be determined from the shape of rhomboid ripple marks. Characteristically these ripples are bowed in the direction of current flow and are pointed up-current. They are formed on the foreshore beach...

...Ervin G. Otvos Abstract Some new thoughts are offered to explain the development of rhomboid-deltoid-shaped surface marks, occurring on marine beaches, usually called "rhomboid ripple marks." Observations on their development and 3260 measurements of their acute angles were employed. The marks...

...FIG. 9. —Rhomboid ripple mark on Lyons sandstone slab. ...

... by this transition but also by downfan energy dissipation within subcritical portions of the flow. From berm crest to fan terminus (i.e., downstream) the lateral sequence of bed geometries is: flat, erosional bed; antidunes; flat bed with primary current lineation and rhomboid rill marks; flat, featureless bed...

...D. J. Cant Abstract In the sandy, braided South Saskatchewan River, ripples, sand waves, and dunes are recognized as lower flow regime bedforms on the basis of a morphological classification. Sand waves are straight-crested to rhomboidal and are very regular in the direction transverse to flow...

... genera that also have the raphe situated largely on or close to the mantle ( Sabbe et al ., 2001 ; Ripple & Kociolek, 2013 ). * (email: [email protected]) 4 7 2014 15 10 2014 © 2015 The Author(s) 2015 Actinella Eocene Eunotia Eunotiophycidae non-marine diatoms...

.... Such couplets represent a lagoonal environment in intertidal zone deposited under the influence of episodic storm events. Krol E Member. Sediments with bedding plane parallel oriented flat pebbles showing wavy and discontinuous layers along with rhomboid ripples are strong evidences of their deposition...

... ENVIRONMENT OF DEPOSITION The rocks of the Jabalpur Formation show good preservation of bedding features. The sandstones and clays are generally lenticular in disposition. The sedimentary structures recorded are parallel bedding, small scale ripple bedding, large and small scale cross bedding, small ripples...

...) Rhomboid ripples. Moralana. F) Sinuous ripple marks. Wilpena Pound. G) Straight-crested ripples with markedly different crest heights. Moralana. H) Undulatory ripples. Bunyeroo Gorge. Coin diameter is 28.5 mm. Ruler is 20 cm long. ...

... with rhomboid ripples or rill marks, which develop on generally planar beds at flow velocities slightly greater than those required for surface lineation. 14 7 2008 17 11 2008 24 11 2008 © 2009 Geological Society of America 2009 The impact of bottom (contour) currents in shaping...

... the transverse bed forms. However, complex ridge bifurcation and sinuosity, rhomboidal ridge forms, and changes in ridge amplitude and wavelength cannot be explained by a glaciotectonic origin for these features. These ridge forms strongly resemble the morphology of depositional bed forms, such as ripples...

... . Type A. Both P. upsilo . Type-A and -B cross cut the burrowed fabric and apparently represent the deepest burrow tier or the final stage of substrate colonization. Physical sedimentary structures, such as starved ripple and current-ripple lamination, are indicative of intermittent bedload...

... ripple shows rippled sandstone surface marked by loading features related to a thin veneer of overlying sandstone ( Fig. 4A ). The evidence for soft sediment deformation of the lower sandy bed and the lack of amalgamation of the two sandy layers is indicative of the presence of mat to provide flexibility...

... predominantly of mollusks, foraminifers, and ostracods. The abrupt change from the limestone to the dolomite facies is accompanied by a marked thinning of the Fort Apache Member and an increase in the amount of quartz silt. Illite and montmorillonite are the principal clay minerals, and kaolinite is abundant...

... tuffites. Gallego et al. (2010) divided the profile into three sections: a lower section composed of tuffites and interbedded claystone with mudcracks; a middle section composed mainly of tuff levels with some tuffite beds with ripple cross-lamination, ripple marks and mudcracks; and an upper section...

... near 0.90 m ( Fig. 4A ). Near 1.25 m, however, F1A grades into nonburrowed, horizontally bedded sand and mud (F2C). Interbeds are composed of current rippled sand with abundant organic detritus on ripple foresets. At 1.57 m, a sharp, undulatory contact is encountered, marking the base...

... temperatures in the Orcadian Basin of between 21 and 29°C ( De Vleeschouwer et al. 2015 ). Middle Devonian palaeo-wind directions were reconstructed by measuring the orientation of over 500 wave ripple marks in Westray ( De Vleeschouwer et al. 2015 ). The presence of two sets of wave oscillation ripples...