33:
305:
281:
257:
filled in with younger, overlying sediment. In most bottom-of-bed examples, the cracks are the part that sticks out most. Bottom-of-bed preservation occurs when mudcracks that have already formed and are completely dried are covered with fresh, wet sediment and are buried. Through burial and pressure, the new wet sediment is further pushed into the cracks, where it dries and hardens. The mudcracked rock is then later exposed to
293:
72:
246:
80:
687:
166:
mudcracks have a geometric pattern. In uncompleted non-orthogonal cracks they form as a single three-point star shape that is composed of three cracks. They could also form with more than three cracks but three cracks in commonly considered the minimum. In completed non-orthogonal cracks, they form a
196:
muds, and dried ponds are localities that form mudcracks. Mudcracks can also be indicative of a predominately sunny or shady environment of formation. Rapid drying, which occurs in sunny environments, results in widely spaced, irregular mudcracks, while closer spaced, more regular mudcracks indicate
91:
and contracts. A strain is developed because the top layer shrinks while the material below stays the same size. When this strain becomes large enough, channel cracks form in the dried-up surface to relieve the strain. Individual cracks spread and join up, forming a polygonal, interconnected network
256:
Mudcracks can be preserved as v-shaped cracks on the top of a bed of muddy sediment or as casts on the base of the overlying bed. When they are preserved on the top of a bed, the cracks look as they did at the time of formation. When they are preserved on the bottom of the bedrock, the cracks are
161:
intersections can have a preferred orientation or may be random. In oriented orthogonal cracks, the cracks are usually complete and bond to one another forming irregular polygonal shapes and often rows of irregular polygons. In random orthogonal cracks, the cracks are incomplete and unoriented
130:
Mudcracks are generally polygonal when seen from above and v-shaped in cross section. The "v" opens towards the top of the bed and the crack tapers downward. Allen (1982) proposed a classification scheme for mudcracks based on their completeness, orientation, shape, and type of infill.
117:
are broadly similar features that form from underwater shrinkage of muddy sediment caused by differences in salinity or chemical conditions, rather than aerial exposure and desiccation. Syneresis cracks can be distinguished from mudcracks because they tend to be discontinuous,
92:
of forms called "tesselations." If the strain continues to build, the polygons start to curl upwards. This characteristic can be used in geology to understand the original orientation of a rock. Cracks may later be filled with sediment and form
183:
layers to separate. The individual top layer is much weaker than multiple layers and is therefore able to contract and form curls as desiccation occurs. If transported by later currents, mud curls may be preserved as mud-chip rip-up clasts.
261:. In these cases, the original mud cracks will erode faster than the newer material that fills the spaces. This type of mudcrack is used by geologists to determine the vertical orientation of rock samples that have been altered through
304:
179:. Mud curls commonly occur on the exposed top layer of very thinly bedded mud rocks. When mud curls form, the water that is inside the sediment begins to evaporate causing the
638:
R. Seghir and S. Arscott "Controlled mud-crack patterning and self-organized cracking of polydimethylsiloxane elastomer surfaces" Sci. Rep. (Nature) 5, 14787 (2015).
32:
667:
424:
280:
162:
therefore they do not connect or make any general shapes. Although they do not make general shapes they are not perfectly geometric.
591:
517:
99:
Typically, the initial crack pattern is dominated by T-shaped junctions. If a mudfield is repeatedly wetted and dried, it can be
712:
225:, paint film, and poorly made concrete. Mudcrack patterning at smaller scales can also be observed studied using technological
292:
100:
146:
network. The connection of cracks often occurs when individual cracks join together forming a larger continuous crack.
717:
347:
108:
63:
and contracts. Crack formation also occurs in clay-bearing soils as a result of a reduction in water content.
192:
Naturally occurring mudcracks form in sediment that was once saturated with water. Abandoned river channels,
398:
56:
606:
M. D. Thouless "Crack
Spacing in Brittle Films on Elastic Substrates" J. Am. Chem. Soc. 73, 2144 (1990).
691:
722:
546:
436:
167:
very geometric pattern. The pattern resembles small polygonal shaped tiles in a repetitive pattern.
150:
are not connected to each other but still form in the same region or location as the other cracks.
622:
Z. C. Xia, J. W. Hutchinson "Crack patterns in thin films" J. Mech. Phys. Solids 48, 1107 (2000).
564:
342:
663:
657:
587:
513:
452:
104:
639:
623:
607:
554:
444:
311:
114:
330:
266:
230:
202:
550:
440:
611:
325:
262:
234:
221:
Polygonal crack networks similar to mudcracks can form in human-made materials such as
210:
206:
627:
197:
that they were formed in a shady place. Similar features also occur in frozen ground,
103:
to a pattern dominated by Y-shaped junctions, as it is thermodynamically favored like
706:
333:, which occur in muds and can look very similar, without requiring subaerial exposure
143:
71:
245:
17:
176:
88:
60:
698:
NEFI: A software that can be used to extract networks from images of mudcracks.
336:
222:
193:
456:
250:
226:
198:
79:
686:
568:
258:
180:
119:
93:
643:
448:
534:
586:(4th ed.). Upper Saddle River, New Jersey: Pearson Education.
559:
78:
70:
31:
372:(4th ed.), American Geological Institute, Alexandria, VA, 769 p.
697:
480:
Sedimentary
Structures: Their Character and Physical Basis
87:
Naturally forming mudcracks start as wet, muddy sediment
423:
Goehring, Lucas; Morris, Stephen W. (1 November 2014).
535:"Some Factors Affecting the Development of Mud-Cracks"
249:
Ancient mudcracks preserved on the base of a bed of
425:"Cracking mud, freezing dirt, and breaking rocks"
175:Mud curls form during one of the final stages in
339:, a similar phenomenon in paintings and ceramics
75:Top layer shrinks and curls up due to the strain
659:Encyclopedia of sediments and sedimentary rocks
8:
584:Principles of Sedimentology and Stratigraphy
558:
490:
488:
364:
362:
126:Morphology and classification of mudcrack
298:Cross-sectional view of ancient mudcrack
244:
83:Crack pattern in clay exposed to the air
474:
472:
470:
468:
466:
358:
286:Bedding plane view of ancient mudcracks
276:
380:
378:
512:(2nd ed.). London: Unwin Hyman.
496:A Practical Approach to Sedimentology
314:(Middle Jurassic) near Gunlock, Utah.
27:Pattern of cracks in dried muddy soil
7:
508:Collinson, J.; Thompson, D. (1989).
612:10.1111/j.1151-2916.1990.tb05290.x
25:
498:, Allen and Unwin, London, 276 p.
122:, and trilete or spindle-shaped.
685:
482:(v. 2): Elsevier, Oxford, 593 p.
388:, Academic Press, London, 320 p.
303:
291:
279:
386:Sedimentary Rocks in the Field
1:
656:Middleton, Gerard V. (2003).
628:10.1016/S0022-5096(99)00081-2
403:Stratigraphic Up Indicators
188:Environments and substrates
739:
348:Polygonal patterned ground
109:polygonal patterned ground
662:. Springer. p. 212.
59:formed as muddy sediment
241:Preservation of mudcrack
135:Completeness of mudcrack
142:form an interconnected
713:Sedimentary structures
533:Kindle, E. M. (1917).
510:Sedimentary Structures
253:
84:
76:
57:sedimentary structures
37:
582:Boggs, J. S. (2006).
478:Allen, J.R.L., 1982,
368:Jackson, J.A., 1997,
248:
82:
74:
67:Formation of mudcrack
35:
694:at Wikimedia Commons
148:Incomplete mudcracks
551:1917JG.....25..135K
494:Linholm, R., 1987,
441:2014PhT....67k..39G
370:Glossary of Geology
539:Journal of Geology
384:Stow, D.A., 2005,
343:Mud cracks on Mars
254:
154:Plan-view geometry
140:Complete mudcracks
85:
77:
49:desiccation cracks
38:
718:Patterned grounds
690:Media related to
669:978-1-4020-0872-6
644:10.1038/srep14787
449:10.1063/PT.3.2584
310:Mudcracks in the
105:columnar jointing
18:Desiccation crack
16:(Redirected from
730:
689:
674:
673:
653:
647:
636:
630:
620:
614:
604:
598:
597:
579:
573:
572:
562:
530:
524:
523:
505:
499:
492:
483:
476:
461:
460:
420:
414:
413:
411:
409:
395:
389:
382:
373:
366:
312:Carmel Formation
307:
295:
283:
235:nanotechnologies
229:deposited using
115:Syneresis cracks
21:
738:
737:
733:
732:
731:
729:
728:
727:
703:
702:
682:
677:
670:
655:
654:
650:
637:
633:
621:
617:
605:
601:
594:
581:
580:
576:
532:
531:
527:
520:
507:
506:
502:
493:
486:
477:
464:
422:
421:
417:
407:
405:
397:
396:
392:
383:
376:
367:
360:
356:
331:Syneresis crack
322:
315:
308:
299:
296:
287:
284:
275:
243:
219:
205:), and igneous
203:columnar basalt
190:
173:
156:
137:
128:
96:over the base.
69:
43:(also known as
36:Fresh mudcracks
28:
23:
22:
15:
12:
11:
5:
736:
734:
726:
725:
720:
715:
705:
704:
701:
700:
695:
681:
680:External links
678:
676:
675:
668:
648:
631:
615:
599:
592:
574:
560:10.1086/622446
545:(2): 135–144.
525:
518:
500:
484:
462:
415:
390:
374:
357:
355:
352:
351:
350:
345:
340:
334:
328:
326:Ground fissure
321:
318:
317:
316:
309:
302:
300:
297:
290:
288:
285:
278:
274:
271:
242:
239:
223:ceramic glazes
218:
215:
189:
186:
172:
169:
164:Non-orthogonal
155:
152:
136:
133:
127:
124:
68:
65:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
735:
724:
721:
719:
716:
714:
711:
710:
708:
699:
696:
693:
688:
684:
683:
679:
671:
665:
661:
660:
652:
649:
645:
641:
635:
632:
629:
625:
619:
616:
613:
609:
603:
600:
595:
593:0-13-154728-3
589:
585:
578:
575:
570:
566:
561:
556:
552:
548:
544:
540:
536:
529:
526:
521:
519:0-04-445172-5
515:
511:
504:
501:
497:
491:
489:
485:
481:
475:
473:
471:
469:
467:
463:
458:
454:
450:
446:
442:
438:
435:(11): 39–44.
434:
430:
429:Physics Today
426:
419:
416:
404:
400:
394:
391:
387:
381:
379:
375:
371:
365:
363:
359:
353:
349:
346:
344:
341:
338:
335:
332:
329:
327:
324:
323:
319:
313:
306:
301:
294:
289:
282:
277:
272:
270:
268:
264:
260:
252:
247:
240:
238:
236:
232:
228:
224:
217:In technology
216:
214:
212:
208:
204:
200:
195:
187:
185:
182:
178:
170:
168:
165:
160:
153:
151:
149:
145:
141:
134:
132:
125:
123:
121:
116:
112:
110:
106:
102:
97:
95:
90:
81:
73:
66:
64:
62:
58:
54:
50:
46:
42:
34:
30:
19:
658:
651:
634:
618:
602:
583:
577:
542:
538:
528:
509:
503:
495:
479:
432:
428:
418:
406:. Retrieved
402:
393:
385:
369:
255:
220:
191:
174:
163:
158:
157:
147:
144:tessellating
139:
138:
129:
113:
98:
86:
52:
48:
44:
40:
39:
29:
723:Desiccation
399:"Mudcracks"
177:desiccation
53:cracked mud
707:Categories
408:26 January
354:References
337:Craquelure
227:thin films
199:lava flows
194:floodplain
181:stratified
159:Orthogonal
45:mud cracks
692:Mudcracks
457:0031-9228
251:sandstone
171:Mud curls
41:Mudcracks
569:30060962
320:See also
267:faulting
101:annealed
89:dries up
547:Bibcode
437:Bibcode
273:Gallery
263:folding
259:erosion
120:sinuous
666:
590:
567:
516:
455:
55:) are
565:JSTOR
231:micro
211:sills
207:dykes
94:casts
61:dries
664:ISBN
588:ISBN
514:ISBN
453:ISSN
410:2022
233:and
209:and
201:(as
107:and
640:doi
624:doi
608:doi
555:doi
445:doi
265:or
51:or
709::
563:.
553:.
543:25
541:.
537:.
487:^
465:^
451:.
443:.
433:67
431:.
427:.
401:.
377:^
361:^
269:.
237:.
213:.
111:.
47:,
672:.
646:.
642::
626::
610::
596:.
571:.
557::
549::
522:.
459:.
447::
439::
412:.
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
