31:
500:
366:
527:
171:
302:
477:
551:
140:-shaped, depending upon the orientation and the shape of the ripples. Ripple cross-laminae will always have a steeper dip downstream, and will always be perpendicular to paleoflow meaning the orientation of the ripples will be in a direction that is ninety degrees to the direction that current if flowing. Scientists suggest current drag, or the slowing of current velocity, during deposition is responsible for ripple cross-laminae.
515:
207:
154:
432:
289:
189:
178:
Sinuous ripples generate cross-laminae that are curvy. They show a pattern of curving up and down as shown in picture. Sinuous ripples produce trough cross lamination. All laminae formed under this type of ripple dip at an angle to the flow as well as downstream. These laminae are also formed by
131:
Ripple cross-laminae forms when deposition takes place during migration of current or wave ripples. A series of cross-laminae are produced by superimposing migrating ripples. The ripples form lateral to one another, such that the crests of vertically succeeding laminae are out of phase and appear
350:. The internal structure of ripples is a base of fine sand with coarse grains deposited on top since the size distribution of sand grains correlates to the size of the ripples. This occurs because the fine grains continue to move while the coarse grains accumulate and provide a protective barrier.
196:
Catenary ripples generate cross-laminae that are curvy but have a unidirectional swoop. They show a pattern similar to what a repeated "W" would look like. Like the sinuous ripples, this form of ripple is created by unidirectional flow with the dip at an angle to the flow as well as downstream.
214:
Linguoid ripples have lee slope surfaces that are curved generating a laminae similar to caternary and sinuous ripples. Linguoid ripples generate an angle to the flow as well as downstream. Linguoid ripples have a random shape rather than a "W" shape, as described in the catenary description.
276:
Large cross-bedding are ripples with a height greater than one meter, and a thickness equivalent to one meter or greater. Some ripples that may fit this category would be high energy river-bed bars, sand waves, epsilon cross-bedding and
Gilbert-type cross-bedding.
393:
These occur in the upper part of the lower flow regime where sand with bimodal particle size distribution forms unusually long wavelength of 1-25 m where the wind is not strong enough to move the larger particles but strong enough to move the smaller grains by
526:
422:, these are formed with fine, well-sorted grain particles accompanied by high velocity winds which result in long, flat ripples. The flat ripples are formed by long saltation paths taken by grains in suspension and grains on the ground surface.
468:
The stoss is the side of a wave or ripple that has a gentle slope versus a steeper slope. Current always flows up the stoss side and down the lee side. This can be used to determine current flow during the time of ripple
255:
Small cross-bedding are ripples set at a height less than ten centimeters, while the thickness is only a few millimeters. Some ripples that may fit this category are wind ripples, wave ripples, and current ripples.
459:
The lee side has a steeper slope than the stoss. The lee is always on the back side of the ripple, which is also on the opposite side of where the current flow meets the ripple. The current flows down the lee
499:
385:
sands with grain sizes between 0.3-2.5 mm and normal ripples form wavelengths of 7-14 cm. Normal ripples have straight or slightly sinuous crests approximately transverse to the direction of the wind.
476:
264:
Medium cross-lamination are ripples with a height greater than ten centimeters, and less than one meter in thickness. Some ripples that may fit this category would be current-formed
161:
Straight ripples generate cross-laminae that all dip in the same direction, and lie in the same plane. These forms of ripples are constructed by unidirectional flow of the current.
627:
Greeley, Ronald, and James D. Iversen. Wind as a
Geological Process On Earth, Mars, Venus and Titan (Cambridge Planetary Science Old). New York: Cambridge UP, 1987.
550:
451:
The opposite of a crest, so the minimum value or height in a wave. It is the location at the very lowest point of a wave cycle also shown in picture to right.
30:
132:
to be advancing upslope. This process results in cross-bedded units that have the general appearance of waves in outcrop sections cut normal to the wave
638:
Monroe, James S., and Reed
Wicander. The Changing Earth: Exploring Geology and Evolution, 2nd ed. Belmont: West Publishing Company, 1997.
443:
The point on a wave with the maximum value or height. It is the location at the peak of the wave cycle as shown in picture to the right.
705:
685:
643:
632:
621:
247:
Very small cross-lamination means that the ripple height is roughly one centimeter. It is lenticular, wavy and flaser lamination.
43:
771:
109:
are asymmetrical in profile, with a gentle up-current slope and a steeper down-current slope. The down-current slope is the
514:
776:
597:
407:
170:
121:
365:
339:
profile; they indicate an environment with weak currents where water motion is dominated by wave oscillations.
616:
Easterbrook, Don J. Surface processes and landforms. Upper Saddle River, N.J: Prentice Hall, 1999. Print.
62:
718:
Tidal deposits of the Lower
Cambrian Random Formation, eastern Newfoundland: facies and paleoenvironments
580:
310:
342:
In most present-day streams, ripples will not form in sediment larger than coarse sand. Therefore, the
301:
395:
215:
Lunate ripples, meaning crescent shaped ripples, are exactly like linguoid ripples except that the
317:
39:
606:- ripples on dirt roads formed by the interaction of vehicle wheels with the gravel and sediment
594:- sedimentary ripple marks show indirect evidence of ancient water flows on our neighbor planet
701:
681:
639:
628:
617:
360:
346:
of sand-bed streams are dominated by current ripples, while gravel-bed streams do not contain
118:
486:
306:
561:
110:
369:
Wind ripples on crescent-shaped sand dunes (Barchans) in
Southwest Afghanistan (Sistan).
575:
506:
490:
765:
591:
585:
533:
78:
603:
206:
382:
125:
70:
153:
756:
751:
746:
741:
736:
483:
343:
336:
265:
658:
Boggs Jr., Sam. (2006) Principles of
Sedimentology and Stratigraphy, 4th ed.
136:. In sections with other orientations, the laminae may appear horizontal or
410:
are a form of fossilized ripple, but there is no conclusive evidence so far.
332:
82:
35:
431:
288:
17:
557:
541:
347:
114:
66:
54:
113:, which depends on the shape of the sediment. These commonly form in
537:
600:- mysterious fossilized features on Mars that resemble giant ripples
721:
430:
364:
300:
287:
74:
29:
742:
Unidirectional flow: Sand ripples and grain distribution 2D model
86:
47:
544:. Ripples climb when sediment fluxes in the flow are very high.
532:
Cross-section through asymmetric climbing ripples, seen in the
188:
667:
Potter, Pettijohn. (1977) Paleocurrents and Basin
Analysis
747:
Unidirectional flow: Sand ripples and topography 2D model
720:, Canadian Journal of Earth Sciences, 19(10), 2028-2042,
27:
Wave structures created in sediments by bottom current
268:, and storm-generated hummocky cross stratification.
124:, and are a signifier of the lower part of the Lower
507:
Wren's Nest
National Nature Reserve, Dudley, England
93:
Defining ripple cross-laminae and asymmetric ripples
752:
Waves: Sand ripples and grain distribution 2D model
698:Sedimentary Rocks in the Field: A Color Guide,
588:- pioneer in description of how ripples formed
381:, these occur in the lower part of the lower
8:
757:Waves: Sand ripples and topography 2D model
520:Wave/symmetrical ripple, Nomgon, Mongolia
223:slope. All other features are the same.
355:Ripple marks formed by aeolian processes
229:
143:
651:
472:
292:Ripple marks at Ile Mavert, Hudson Bay
284:Ripple marks in different environments
7:
737:Ripple Marks and Uniformitarianism
25:
493:. Scale bar on notebook is 10 cm.
219:sides are curved rather than the
549:
525:
513:
498:
475:
205:
187:
169:
152:
722:https://doi.org/10.1139/e82-180
678:Sedimentology and Stratigraphy,
1:
34:Ancient wave ripple marks in
179:the unidirectional current.
73:) and indicate agitation by
716:Hiscott, Richard N. (1982)
406:There is some thought that
793:
696:Stow, Dorrik A.V., (2009)
358:
315:
44:Capitol Reef National Park
598:Transverse aeolian ridges
408:transverse aeolian ridges
403:Transverse aeolian ridges
305:Tidal megaripples in the
122:depositional environments
107:asymmetrical ripple marks
556:Complex ripple marks on
329:symmetrical ripple marks
772:Sedimentary structures
676:Nichols, Gary. (2009)
436:
370:
313:
293:
103:unidirectional ripples
63:sedimentary structures
50:
581:Giant current ripples
434:
368:
325:bidirectional ripples
304:
291:
33:
99:Current ripple marks
505:Ripple beds in the
420:aerodynamic ripples
297:Wave-formed ripples
232:
146:
437:
415:Fluid drag ripples
371:
318:Wave-formed ripple
314:
294:
230:
203:Linguoid / Lunate
144:
51:
40:Moenkopi Formation
777:Patterned grounds
361:Aeolian processes
281:
280:
228:
227:
85:) or directly by
16:(Redirected from
784:
724:
714:
708:
700:Academic Press,
694:
688:
674:
668:
665:
659:
656:
646:pp. 114-15, 352.
553:
529:
517:
502:
487:Dakota Formation
482:Ripple marks in
479:
435:Crest and trough
307:Random Formation
233:
209:
191:
173:
156:
147:
21:
792:
791:
787:
786:
785:
783:
782:
781:
762:
761:
733:
728:
727:
715:
711:
695:
691:
675:
671:
666:
662:
657:
653:
613:
572:
565:
562:Blackberry Hill
554:
545:
530:
521:
518:
509:
503:
494:
489:, east side of
480:
429:
363:
357:
320:
299:
286:
111:angle of repose
95:
28:
23:
22:
15:
12:
11:
5:
790:
788:
780:
779:
774:
764:
763:
760:
759:
754:
749:
744:
739:
732:
731:External links
729:
726:
725:
709:
706:978-0123694515
689:
686:978-1405135924
669:
660:
650:
649:
648:
647:
636:
625:
612:
609:
608:
607:
601:
595:
589:
583:
578:
576:Capillary wave
571:
568:
567:
566:
560:tidal flat at
555:
548:
546:
531:
524:
522:
519:
512:
510:
504:
497:
495:
491:Dinosaur Ridge
481:
474:
471:
470:
466:
462:
461:
457:
453:
452:
449:
445:
444:
441:
428:
425:
424:
423:
418:Also known as
416:
412:
411:
404:
400:
399:
391:
387:
386:
379:impact ripples
377:Also known as
375:
374:Normal ripples
356:
353:
352:
351:
340:
316:Main article:
298:
295:
285:
282:
279:
278:
274:
270:
269:
262:
258:
257:
253:
249:
248:
245:
241:
240:
237:
226:
225:
211:
200:
199:
193:
182:
181:
175:
164:
163:
158:
142:
141:
129:
94:
91:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
789:
778:
775:
773:
770:
769:
767:
758:
755:
753:
750:
748:
745:
743:
740:
738:
735:
734:
730:
723:
719:
713:
710:
707:
703:
699:
693:
690:
687:
683:
679:
673:
670:
664:
661:
655:
652:
645:
644:0-314-09577-2
641:
637:
634:
633:0-521-35962-7
630:
626:
623:
622:0-13-860958-6
619:
615:
614:
610:
605:
602:
599:
596:
593:
592:Water on Mars
590:
587:
586:Hertha Ayrton
584:
582:
579:
577:
574:
573:
569:
563:
559:
552:
547:
543:
539:
535:
534:Zanskar Gorge
528:
523:
516:
511:
508:
501:
496:
492:
488:
485:
478:
473:
467:
464:
463:
458:
455:
454:
450:
447:
446:
442:
439:
438:
433:
426:
421:
417:
414:
413:
409:
405:
402:
401:
397:
392:
389:
388:
384:
380:
376:
373:
372:
367:
362:
354:
349:
345:
341:
338:
334:
330:
326:
322:
321:
319:
312:
308:
303:
296:
290:
283:
275:
272:
271:
267:
263:
260:
259:
254:
251:
250:
246:
243:
242:
238:
235:
234:
231:Size (scale)
224:
222:
218:
212:
210:
208:
202:
201:
198:
194:
192:
190:
184:
183:
180:
176:
174:
172:
166:
165:
162:
159:
157:
155:
149:
148:
139:
135:
130:
127:
123:
120:
116:
112:
108:
104:
100:
97:
96:
92:
90:
88:
84:
80:
76:
72:
69:of the lower
68:
64:
60:
56:
49:
45:
41:
37:
32:
19:
717:
712:
697:
692:
677:
672:
663:
654:
624:pp. 479-480.
604:Washboarding
564:, Wisconsin.
540:, NW Indian
419:
378:
328:
324:
323:Also called
311:Newfoundland
239:Description
220:
216:
213:
204:
195:
186:
177:
168:
160:
151:
137:
133:
106:
102:
98:
59:ripple marks
58:
52:
635:pp. 153-154
427:Definitions
390:Megaripples
383:flow regime
344:stream beds
333:symmetrical
244:Very small
126:Flow Regime
71:flow regime
766:Categories
611:References
484:Cretaceous
469:formation.
359:See also:
337:sinusoidal
266:sand waves
18:Megaripple
396:saltation
335:, almost
185:Catenary
150:Straight
36:sandstone
570:See also
558:Cambrian
542:Himalaya
348:bedforms
167:Sinuous
67:bedforms
680:Wiley,
331:have a
261:Medium
119:aeolian
115:fluvial
79:current
65:(i.e.,
55:geology
704:
684:
642:
631:
620:
538:Ladakh
448:Trough
273:Large
252:Small
145:Types
138:trough
134:crests
465:Stoss
460:side.
440:Crest
327:, or
217:stoss
105:, or
83:waves
75:water
702:ISBN
682:ISBN
640:ISBN
629:ISBN
618:ISBN
236:Size
117:and
87:wind
61:are
48:Utah
456:Lee
309:in
221:lee
81:or
53:In
768::
536:,
101:,
89:.
57:,
46:,
42:,
38:,
398:.
128:.
77:(
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
