290:
360:. These strata have been subdivided, in ascending order, into the Carbon Butte, Awatubi, and Walcott members. The Carbon Butte Member consists largely of sandstone interbedded with carbonates and, locally, ironstones. The Awatubi Member consists of a distinctive zone of stromatolitic bioherms at its base overlain by grey, green, and black organic-rich siltstones and shales, some of which contain marcasite nodules. The base of the Walcott Member consists of a distinctive meter-scale laminated dolomite bed (the
219:
187:
200:
280:
of the Chuar Group strata is limited to exposures along the western bank of the
Colorado River in a 150 km (58 sq mi) area of the eastern Grand Canyon, Arizona. The strata of the Chuar Group have been subdivided into the Galeros Formation (lower) and the Kwagunt Formation (upper) using
466:
The types of fossils found and sedimentary strata comprising the Chuar Group are indicative of its deposition within a low-energy marine embayment. During the deposition of the Chuar Group, this embayment was influenced by tidal and wave processes, infrequent large storms, microbial activity and
449:
The age of the Chuar Group is well constrained between as being 729 and 782 Ma by Re-Os and U-Pb ages. First, U–Pb dating of detrital zircons from basal beds of the underlying
Nankoweap Formation indicates it to be less than 782 Ma. Second, Re–Os ages from organic-rich carbonates in the upper
408:. The gray and black mudrocks of the Duppa, Carbon Canyon, Jupiter, and Tanner members of the Chuar Group often contain organic-walled microfossils, including filaments, colonial forms, and both smooth-walled and ornamented vesicles. A morphological group of organic microfossil, called
329:
have been subdivided, in ascending order, into the Tanner, Jupiter, Carbon Canyon, and Duppa members. Dolomite is dominate in all of these members. Thick (meter-scale) basal dolomite beds define the Tanner and
Jupiter members. In case of the Jupiter Member, the basal dolomite bed is
467:
carbonate precipitation, and the accumulation of mud and organic matter in quiet water. The sediments and fossils suggest that the Chuar Group accumulated in relatively shallow water (tens of meters or less), possibly, with times of intermittent exposure on a tidal flat.
379:
beds. The mudrocks are typically gray to black when freshly exposed and weather to reddish or greenish colors. The fresh gray to black colors of the mudrocks are due to a high organic content. Some samples of these mudrocks contain high
1284:
450:
Galeros
Formation and marcasite nodules in the lower Kwagunt Formation yielded ages of 757.0 ± 6.8 and 751.0 ± 7.6 Ma, respectively. Finally, an U–Pb age obtained from CA-ID-TIMS analysis of
574:
Dehler, CM, SM Porter, and JM Timmons (2012) "The
Neoproterozoic Earth system revealed from the Chuar Group of Grand Canyon", in JM Timmons and KE Karlstrom, eds., pp. 49–72,
548:
Ford, TD, and CM Dehler (2003) "Grand Canyon
Supergroup: Nankoweap Formation, Chuar Group, and Sixtymile Formation." in: Beus, S.S., Morales, M., eds., pp. 49–72,
458:
the top of the
Walcott Member is 729.0 ± 0.9 Ma. These ages also indicate that the vase-shaped microfossils-bearing Walcott Member is between 751 and 729 Ma.
803:
The Great
Unconformity and the Late Proterozoic-Cambrian Time Interval: Part II – The Rifting of Rodinia and the "Snowball Earth" Glaciations That Followed.
627:
Lahr, D.J., Kosakyan, A., Lara, E., Mitchell, E.A., Morais, L., Porfirio-Sousa, A.L., Ribeiro, G.M., Tice, A.K., Pánek, T., Kang, S. and Brown, M.W., 2019.
716:
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Synthesis of the 780–740 ma Chuar, Uinta
Mountain, and Pahrump (ChUMP) groups, western USA: Implications for Laurentia-wide cratonic marine basins
801:
793:
776:
756:
630:
Phylogenomics and morphological reconstruction of
Arcellinida testate amoebae highlight diversity of microbial eukaryotes in the Neoproterozoic
412:, occur within the Walcott and Awatubi members of the Kwagunt Formation along with the enigmatic, circular, macroscopic, organic-walled fossil
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666:
Rooney, A.D., Austermann, J., Smith, E F., Li, Y., Selby, D., Dehler, C.M., Schmitz, M.D., Karlstrom, K.E., and Macdonald, F.A. 2018.
405:
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Grand Canyon Supergroup Six Unconformities Make One Great Unconformity A Record of Supercontinent Assembly and Disassembly
809:
1379:
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364:). The Flakey dolomite is overlain by silicified oolites, chert beds, black shales. A pair of meter-scale dolomite beds (
646:
Dehler, C.M., Gehrels, G., Porter, S.M., Heizler, M., Karlstrom, K.E., Cox, G., Crossey, L.J., and Timmons, J.M., 2017.
400:
The Chuar Group conatins a variety of Neoproterozoic fossils. The dolomite beds contain at least six different types of
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368:) occur in the upper Walcott along with early diagenetic dolomite nodules up to 1 m (3.3 ft) in diameter.
1340:
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The Great Unconformity of the Grand Canyon and the Late Proterozoic-Cambrian Time Interval: Part I – Defining It.
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percentages that are as much 9.39 weight percent organic carbon. The sandstone beds often exhibit symmetrical
901:
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Organic preservation of vase‐shaped microfossils from the late Tonian Chuar Group, Grand Canyon, Arizona, USA
1125:
979:
513:
Contributions to the geology of the Grand Canyon, Arizona; the geology of the Shinumo area (continued).
891:
846:
628:
502:
14th Annual Report for 1892/3, part 2, pp. 492–519, United States Geological Survey, Reston, Virginia.
422:), and phosphatic scale microfossils. The vase-shaped microfossils are likely presentatives of either
260:
consists of 1,600 m (5,200 ft) of exceptionally well-preserved, unmetamorphosed sedimentary
593:
Natural Resource Report NPS/GRCA/NRR—2021/2246. National Park Service, Fort Collins, Colorado. 36 pp.
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The mudrocks of the Galeros and Kwagunt formations are normally interbedded with meter-thick
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Tingle, K.E., Porter, S.M., Raven, M.R., Czaja, A.D., Webb, S.M. and Bloeser, B., 2023.
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The Grand Age of Rocks: The Numeric Ages for Rocks Exposed within Grand Canyon
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Precambrian igneous rocks of the Unkar terrane, Grand Canyon of the Colorado.
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Coupled Re-Os and U-Pb geochronology of the Tonian Chuar Group, Grand Canyon
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National Register of Historic Places listings in Grand Canyon National Park
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578:. Special Paper no. 489, Geological Society of America, Boulder, Colorado.
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Mountain Press Publishing Co., 1983, 23rd printing, pp. 229–232,
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Karlstrom, K., Crossey, L., Mathis, A., and Bowman, C., 2021.
828:, National Park Service, Grand Canyon National Park, Arizona.
789:, National Park Service, Grand Canyon National Park, Arizona.
353:
349:
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American Journal of Science. Series 4, vol. 29, pp. 497–528.
455:
205:
576:
Grand Canyon Geology: Two Billion Years of Earth's History
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Bulletin no. 549, US Geological Survey, Reston, Virginia.
590:
Telling time at Grand Canyon National Park: 2020 update.
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Grand Canyon Association (publisher), 2008, 176 pages,
526:
The Shinumo quadrangle, Grand Canyon district, Arizona.
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746:Stratigraphy of the Parks of the Colorado Plateau
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281:the base of the prominent, thick sandstone unit.
268:. The Group is the approximate upper half of the
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808:Timmons, M. K. Karlstrom, and C. Dehler (1999)
433:, or some of both. Finally, organic chemicals,
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494:
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1280:List of trails in Grand Canyon National Park
748:. U.S. Geological Survey, Reston, Virginia.
16:Part of the geologic Grand Canyon Supergroup
689:Ancient Landscapes of the Colorado Plateau,
489:
854:
840:
816:Boatman's Quarterly Review. vol. 12, no. 1
406:microbially induced sedimentary structures
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985:Grand Canyon–Parashant National Monument
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718:Overview of the Grand Canyon Supergroup
681:
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348:is composed of sandstones, siltstones,
272:, overlain by the thin, in comparison,
133:1,600 m (5,200 ft) at maximum
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826:(Grand Canyon Geology Training Manual)
777:Unkar Group of Grand Canyon Supergroup
757:Chuar Group of Grand Canyon Supergroup
672:Geological Society of America Bulletin
652:Geological Society of America Bulletin
835:
247:Walcott (1894) and Noble (1910, 1914)
1249:Powell Geographic Expedition of 1869
824:Learning to Read the Pages of a Book
552:. Oxford University Press, New York.
334:. The Carbon Canyon Member contains
305:consists of a series of meter-scale
1254:1956 Grand Canyon mid-air collision
13:
14:
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783:Mathis, A., and C. Bowman (2007)
739:
1341:Grand Canyon: The Hidden Secrets
1275:Grand Canyon Backcountry Camping
861:
477:Geology of the Grand Canyon area
217:
198:
185:
37:
1334:The Man Who Walked Through Time
366:upper and lower dolomite couple
1348:Grand Canyon: A Different View
1259:Grand Canyon Airlines Flight 6
687:Blakey, Ron and Wayne Ranney,
284:
264:that is composed of about 85%
1:
902:Grand Canyon Village, Arizona
482:
1385:Neoproterozoic North America
728:2001, Mountaineers's Books,
703:Roadside Geology of Arizona,
7:
980:Grand Canyon Forest Reserve
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1380:Geologic groups of Arizona
892:Grand Canyon National Park
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726:Hiking Arizona's Geology,
721:; Grand Hikes; accessed .
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1290:Grand Canyon Conservancy
410:vase-shaped microfossils
309:composed of interbedded
1111:Uinkaret volcanic field
990:Grand Canyon Supergroup
877:Black Suspension Bridge
321:, frequently capped by
270:Grand Canyon Supergroup
86:Grand Canyon Supergroup
1328:(2017 children's book)
821:Timmons, S. S. (2003)
444:
298:
1354:Grand Canyon Escalade
1318:A Bigger Grand Canyon
1174:Little Colorado River
887:Grand Canyon Escalade
637:, 29(6), pp.991-1001.
293:Figure 1. A geologic
292:
975:Grand Canyon Caverns
965:Ericameria arizonica
897:Grand Canyon Skywalk
682:Popular Publications
674:, 130, pp.1085–1098.
615:, 21(3), pp.290-309.
550:Grand Canyon Geology
462:Depositional Setting
441:have been reported.
437:, characteristic of
382:total organic carbon
297:of the Grand Canyon.
108:and, as part of the
76:Geological formation
1005:Sixtymile Formation
1000:Nankoweap Formation
970:Esplanade Sandstone
800:Share, J. (2102a)
792:Share, J. (2102a)
772:Nankoweap Formation
752:Sixtymile Formation
654:, 129, pp.607– 624.
498:Walcott, CD (1894)
274:Sixtymile Formation
124:Nankoweap Formation
106:Sixtymile Formation
28:Stratigraphic range
1296:Grand Canyon Suite
1179:Bright Angel Creek
1099:Bright Angel Shale
940:Agave phillipsiana
715:Keller, B.; 2012;
420:Churnia circularis
307:sedimentary cycles
299:
110:Great Unconformity
95:Kwagunt Formation
1362:
1361:
1303:Desert Wonderland
1079:Redwall Limestone
1049:Hyaloclastite Dam
1020:Shinumo Quartzite
912:Marble Canyon Dam
882:Bridge Canyon Dam
818:, pp. 29–32.
767:Galeros Formation
762:Kwagunt Formation
711:978-0-87842-147-3
524:Noble, LF (1914)
511:Noble, LF (1910)
454:recovered from a
346:Kwagunt Formation
303:Galeros Formation
251:
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114:Tapeats Sandstone
97:Galeros Formation
1392:
1116:Vasey's Paradise
1044:Hermit Formation
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701:Chronic, Halka.
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1321:(1998 painting)
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1332:
1326:Grand Canyon
1325:
1316:
1310:Grand Canyon
1309:
1301:
1294:
1162:Havasu Falls
1157:Havasu Creek
1121:Venus Temple
1089:Temple Butte
1074:Prospect Dam
1064:Newton Butte
1034:Freya Castle
994:
917:Maswik Lodge
863:Grand Canyon
823:
810:
802:
794:
785:
725:
717:
702:
688:
671:
667:
651:
647:
642:
634:
629:
612:
608:
589:
583:
575:
549:
525:
520:
512:
507:
499:
465:
448:
419:
413:
409:
399:
386:ripple marks
370:
365:
361:
345:
343:
336:stromatolite
302:
300:
257:
252:
239:Chuar Canyon
231:Type section
177:Grand Canyon
1312:(1958 film)
1205:Kenton Grua
1169:Kanab Creek
1094:Tonto Group
1069:Ochoa Point
1054:Isis Temple
1010:Unkar Group
995:Chuar Group
907:Kolb Studio
285:Description
258:Chuar Group
208:-(southern)
48:Proterozoic
22:Chuar Group
1369:Categories
1210:John Hance
1152:Deer Creek
870:Facilities
613:Geobiology
483:References
435:biomarkers
431:acritarchs
424:arcellinid
358:ironstones
319:sandstones
315:siltstones
175:(eastern)
1226:Havasupai
390:mudcracks
373:sandstone
236:Named for
195:-(north)
161:sandstone
138:Lithology
130:Thickness
102:Underlies
92:Sub-units
1231:Hualapai
471:See also
377:dolomite
339:bioherms
325:. These
311:mudrocks
244:Named by
167:Location
157:dolomite
147:mudstone
120:Overlies
1268:Related
932:Geology
456:tuff at
452:zircons
396:Fossils
278:outcrop
266:mudrock
213:Country
193:Arizona
143:Primary
82:Unit of
55:Archean
1241:Events
1219:Tribes
1188:People
732:
709:
695:
415:Tawuia
356:, and
354:cherts
350:shales
327:strata
317:, and
262:strata
222:
203:
190:
172:Region
112:, the
153:Other
730:ISBN
707:ISBN
693:ISBN
404:and
375:and
344:The
301:The
253:The
206:Utah
159:and
72:Type
62:Had.
41:Pha.
445:Age
429:,
341:.
1371::
814:.
670:.
659:^
650:.
620:^
611:.
598:^
557:^
533:^
491:^
392:.
313:,
30::
855:e
848:t
841:v
632:.
418:(
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