331:
84:
339:
427:
986:. Shortly after 1890, mining claims were filed on these asbestos deposits. Later in the early 1900s, William Wallace Bass mined asbestos in the Shinumo Creek-Hakatai Canyon area and John Hance mined asbestos in Asbestos Canyon. Although these deposits had good quality asbestos, little asbestos, at most a few tons, was produced from them because these deposits were fairly small and difficult to access. These asbestos mines are now abandoned and protected as historical sites.
242:
1055:
1041:
1024:. As in the case of the Bass Formation, these chrysotile asbestos deposits are of the contact metamorphic type that occur in magnesium-bearing Mesoproterozoic dolomites and limestones altered by basaltic dikes and sills. As in the case of the Grand Canyon asbestos deposits, dolomite and limestone reacted with silica-bearing fluids, heated by the basalt intrusions, forming the
694:
533:
The base of both the Bass
Formation and Unkar Group in eastern Grand Canyon is marked by the Hotauta Member of the Bass Formation. It is a prominent discontinuous, conglomerate, initially named the Hotauta Conglomerate and later redesignated the Hotauta Member. This conglomerate consists of rounded,
963:
having been erupted about 1,104 Ma. Finally, the uranium-lead dating of zircons is consistent with studies of the underlying Vishnu
Basement Rocks that indicate they were exhumed from depths of 25 to 10 km depths between 1,750 and 1,660 Ma and from a depth of 10 km to the surface on which
626:
sills and dikes intrude all strata of the Unkar Group that underlie the
Cardenas Lava. Only sills, whose feeder dikes are not exposed, can be observed intruding the Bass Formation. Where the sills have intruded siliceous dolomites in the Bass Formation, metasomatism and recrystallization have
665:
This contact is a remarkably smooth surface that has a relief of about 6 m (20 ft) in the
Shinumo 15-minute topographic quadrangle and 15 m (49 ft) in the Bright Angel and Vishnu 15-minute topographic quadrangles. In Hotauta Canyon, and at Granite Narrows, this surface is
799:
Walcott, have been reported from the Bass
Formation so far. The environment, in which these stromatolites grew, as judged by the associated sediments, was one of quiet, shallow marine waters. The common presence of ripple-marks and mud-cracks suggest intermittent desiccation. Thin layers of
1217:
In DP Elston, GH Billingsley, and RA Young, RA., eds., pp. 94–105, Geology of the Grand Canyon, Northern
Arizona (with Colorado River Guides). American Geophysical Union Fieldtrip Guidebook T115/315 for International Geologic Congress, 28th. American Geophysical Union, Washington DC. 239
496:
Dolomite and limestone dominate the Bass
Formation in the central part of the Grand Canyon, while the sandstone, conglomerate, and argillite dominate the Bass Formation in the eastern part of the Grand Canyon. The Bass Formation typically becomes generally finer grained toward the top.
1028:
mineral chrysotile. Much like the Grand Canyon asbestos deposits, these basaltic sills and dikes range in age from 1,050 to 1,140 Ma. Quite unlike the Grand Canyon asbestos deposits, the asbestos deposits of the Sierra Ancha-Salt River Canyon region have been extremely productive.
685:
of the underlying basement rocks – is present. Typically, this regolith consists of a dark-reddish brown, structureless, ferruginous sediment that is usually a few centimeters to 30 cm (0.98 ft) thick. This contact is regarded as a classic example of an ancient
637:
The Bass
Limestone shows generally, an increase in thickness to the northwest ranging from 37 (121 ft) to 104 m (341 ft) thick. Its average thickness is 80 m (260 ft). It is 100 m (330 ft) thick at Phantom Creek (north side of
673:
The Vishnu
Basement Rocks underlying this surface are often deeply weathered to an average depth of 3 m (9.8 ft) below it. Where it has not been removed by erosion, prior to, and during the deposition of the overlying Bass Formation, a residual
718:
In the eastern part of the Grand Canyon, the contact between the Bass
Formation and the overlying Hatakai Shale is typically gradational over an interval of a meter or so. For example, in Red Canyon, the contact consists of an interval in which
1929:
642:, Cheops Pyramid, & Utah Flats), and 57 m (187 ft) thick at Crystal Creek. The thin section of Bass Formation at Crystal Creek likely reflects the presence of a Vishnu Basement Rocks topographic high in the
886:. This limestone largely accumulated in clear, relatively warm, shallow marine waters by both biological and abiological processes. During the maximum, deepest, incursion of marine waters, limestone and deep-water
894:
and shallow-water mud accumulated in the eastern Grand Canyon. Following the maximum incursion of marine waters, the sea slowly regressed, and it accumulated in nearshore and coastal environments as indicated by
634:, both above and below the sills. Veins of asbestos with fibers up to 10 cm (3.9 in) in length, often commonly occur within 3 m (9.8 ft) of the upper and lower contacts of the sills.
1201:
Dalton, Russell O., Jr. (1972) "Stratigraphy of the Bass Formation (Late Precambrian, Grand Canyon, Arizona)". Unpublished Master’s thesis, Northern Arizona University : Flagstaff, Arizona. 140 pp.
313:
that dip 60+° toward the southwest. This can be seen at the Palisades fault in the eastern part of the main Unkar Group outcrop area (below East Rim). In addition, thick, prominent, and dark-colored
878:
sediments buried the fluvial deposits of the Hotauta Member as a smooth surface, with a local relief of probably no more than 150 feet (46 m) of the Vishnu Basement Rocks, being submerged by a
1183:
Tectonic inferences from the ca. 1254–1100 Ma Unkar Group and Nankoweap Formation, Grand Canyon: Intracratonic deformation and basin formation during protracted Grenville orogenesis
1159:
In JM Timmons and KE Karlstrom, eds., pp. 7–24, "Grand Canyon geology: Two billion years of earth's history". Special Paper no 294, Geological Society of America, Boulder, Colorado.
1255:
In JM Timmons and KE Karlstrom, eds., pp. 25–47, Grand Canyon geology: Two billion years of earth's history. Special Paper no 294, Geological Society of America, Boulder, Colorado.
330:
83:
959:
strata interpreted to be correlative with the Bass Formation and its age estimated from earlier paleomagnetic studies. In addition, this date is consistent with the younger
762:), that are now buried by sandstones, shales, and conglomerates of the Tapeats Sandstone. These monadnocks served locally as sources of coarse-grained sediments during the
2071:
955:. Zircons from air-fallen, volcanic ash beds in its lower part yielded a uranium-lead date of 1,254.8 ± 1.6 Ma. This date is consistent with radiometric ages of
662:, which consists of granites, gneisses, pegmatites, and schists of the Vishnu Basement Rocks, from stratified Proterozoic rocks of the Grand Canyon Supergroup.
489:
are also found throughout the Bass Formation. The dolomites and limestones vary in color from gray to red-gray and sometimes contain biscuit-form and biohermal
1649:
2056:
1924:
569:. The quartzite gravel lacks any local equivalents in the Grand Canyon, indicating a distant source. Excellent exposures of the Hotauta Member occur at the
485:
and dolomite, and subordinate interbeds of argillite and limestone. Dolomite and sandy dolomite are the predominant lithologies. Beds of intraformational
851:
The lithology and sedimentary structures observed in the Bass Limestone indicate that, except for the Hotauta Member, it accumulated beneath a sea that
827:
have been reported from the Bass Formation. Critical examinations of these reported fossils have concluded that the fossil sponges are inorganic silica
1438:
658:
that also forms the base of the Grand Canyon Supergroup and the Unkar Group. This unconformity separates the underlying and deeply eroded crystalline
800:
flake-breccia associated with them indicate occasional periods of turbulence of brief duration. However, direct evidence specifically indicating an
2051:
507:, that are interbedded with dolomite and argillite toward the base of the formation. These layers are characterized by sharp basal contacts, some
461:
in 1914 as a separate unit of formation status for Hotauta Canyon. It was later included in the Bass Formation as a member where it has remained.
1229:
Mudstone petrology of the Mesoproterozoic Unkar Group, Grand Canyon, USA: provenance, weathering and sediment transport on intracratonic Rodinia.
1523:
1423:
Hance Mine (Hance property; Hance Asbestos Company Mine), Shinumo quadrangle, Grand Canyon, Grand Canyon District, Coconino Co., Arizona, USA.
915:-forming conditions probably occurred, also during this regressive phase. Eventually, a shallow, near-shore marine environment, coastal plain
608:; and local channel fills. The dolomite and limestone within the Bass formation have been affected by post-depositional alteration including:
882:
from the west. The dolomite of the Bass Formation likely was originally deposited as limestone and subsequently altered to dolomite by later
1893:
983:
770:. The contact between the Bass Formation and the Tapeats Sandstone forms part of a relative flat surface that lies between the monadnocks.
1009:-zone associated with basaltic sills. For unknown reasons, claims were never filed on these veins and no attempts were made to mine them.
1399:
1898:
1451:
1445:
368:
The Unkar Group is about 1,600 to 2,200 m (5,200 to 7,200 ft) thick and composed of, in ascending order, the Bass Formation,
2066:
839:
of unknown affinity, which were reported from the Bass Formation, are now judged to be rounded mud-flakes or pellets that are likely
358:
and a section of the layered Bass Limestone (note horizontal layering & dk blackish-brown color) – visible below the cliffs of
670:
where low rounded hills of Vishnu Basement Rocks rise 6 m (20 ft) above the general level of a relatively flat surface.
2061:
1985:
1919:
1885:
1601:
1068:
727:
sedimentary rock of the overlying Hakatai Shale. In the eastern part of the Grand Canyon, the contact is sharp, but conformable.
1978:
989:
In the mid-1960s, Gregory H. Billingsley found several veins of asbestos up to 7.6 cm (3.0 in) thick at the mouth of
874:
of the Hotauta Member were deposited by river systems that extended some unknown distance outside of the Grand Canyon region.
1992:
1903:
493:
beds. The conglomerates, breccias, sandstones, and argillites vary in color from purple-brown to dark red and reddish brown.
293:. The Bass Formation erodes as either cliffs or stair-stepped cliffs. In the case of the stair-stepped topography, resistant
666:
extremely smooth with a relief of only a few meters. The greatest relief on this surface can be seen opposite the mouth of
1571:
1481:
Grand Canyon Supergroup Six Unconformities Make One Great Unconformity A Record of Supercontinent Assembly and Disassembly
1479:
1253:
The Grand Canyon Unkar Group: Mesoproterozoic basin formation in the continental interior during supercontinent assembly.
1644:
2012:
338:
1561:
1516:
1485:
784:
occur within the Bass Formation. Diagnostic “columnar forms” of stromatolites are uncommon. Of these forms, only
1953:
1934:
1412:
Bass Mine (Bass property; Asbestos Camp), Bass Ferry vicinity, Grand Canyon region, Coconino Co., Arizona, USA.
290:
282:
1389:
426:
1765:
1654:
1546:
601:
400:
1155:
Karlstrom, KE, BR Ilg, Bradley, D Hawkins, ML Williams, G Dumond, KK. Mahan, and SA Bowring, Samuel (2012)
1133:
In SS Beus and M Morales, eds., pp. 39–52, Grand Canyon Geology, 2nd ed. Oxford University Press, New York.
940:
1728:
871:
589:
482:
177:
1012:
The Grand Canyon asbestos deposits are very similar in origin and nature to the asbestos deposits of the
434:
There has been some discussion about the nomenclature of the Bass Formation. It was originally named the
1998:
1962:
1818:
1556:
1509:
948:
420:
355:
257:
135:
993:. These veins outcrop upstream along the Colorado River for nearly two miles up to Stone Creek. Green
1796:
1639:
1629:
1566:
1432:
1157:
Vishnu Basement Rocks of the Upper Granite Gorge: Continent formation 1.84 to 1.66 billion years ago.
1021:
1006:
879:
852:
763:
97:
1297:
In ET Drake, ed., pp. 1–72, Evolution and Environment, Yale University Press, Princeton, New Jersey.
1969:
1770:
1669:
1664:
1634:
932:
667:
527:
393:
385:
351:
1005:
are associated with the asbestos veins, which occur in a 0.6-to-0.9 m (2-to-3 ft) thick
1940:
1823:
1753:
1609:
1073:
743:
659:
582:
578:
574:
1775:
1392:
343:
334:
Close-up showing a light rock color, but the multiple layers of bedding in the Bass Formation.
1947:
1733:
1708:
1684:
1581:
1551:
1330:. Museum of Northern Arizona, and Grand Canyon Natural History Association, Flagstaff, Arizona
1017:
835:
colonies; and the worm trails are inorganic sedimentary structures. In addition, fossils of a
755:
731:
707:
512:
373:
359:
1703:
1025:
539:
457:
is only a minor rock type. In addition, its Hotauta Member was originally designated as the
447:
347:
1492:
1470:
1839:
1693:
1619:
960:
801:
751:
381:
310:
294:
279:
241:
162:
31:
923:
that marked the beginning of Hakatai Shale deposition – dominated the Grand Canyon area.
1844:
1791:
1760:
1144:
Age and correlation of the late Proterozoic Grand Canyon disturbance, northern Arizona.
1060:
1046:
994:
979:
875:
866:
that accumulated within valleys on an eroded surface of the Vishnu Basement Rocks. The
735:
617:
609:
605:
570:
519:
508:
503:
layers occur in the Bass Formation. They consist of layers of white, very fine-grained
317:
982:
in the Bass Formation was first noted in early exploration of the Grand Canyon by the
2045:
1738:
1718:
1698:
1624:
1614:
1591:
1390:
Abandoned asbestos mine, near Hakatai Rapids, mile 111, Colorado River, Grand Canyon.
1181:
Timmons, JM, KE Karlstrom, MT Heizler, SA Bowring, GE Gehrels, and LJ Crossey (2005)
990:
711:
446:
by geologists because it consists of heterogeneous mixtures of clastic and carbonate
377:
369:
250:
212:
125:
27:
1458:
565:
in a quartz sand matrix. About 80% of the gravel-size clasts consist of granite and
1806:
1801:
1743:
1723:
1586:
1532:
1251:
Timmons, JM, J. Bloch, K. Fletcher, KE Karlstrom, M Heizler, and LJ Crossey (2012)
1054:
1013:
891:
781:
739:
724:
720:
655:
643:
593:
543:
500:
490:
302:
286:
202:
139:
1395:, Special Collections and Archives, Arizona State University, Flagstaff. Arizona.
604:; interformational breccias/conglomerates; both normal and reversed small-scale,
430:
Multiple bedding layers in dk brown Bass Formation, below colorful Hakatai Shale.
403:, of which the Bass Formation is the lowermost formation, overlies deeply eroded
1849:
1813:
1748:
1713:
1674:
1659:
1576:
956:
952:
920:
896:
767:
699:
639:
555:
389:
324:
306:
263:
107:
49:
42:
1463:
1282:
Chuaria circularis Walcott and other Precambrian fossils from the Grand Canyon.
1854:
1447:
The Grand Age of Rocks: The Numeric Ages for Rocks Exposed within Grand Canyon
1036:
973:
883:
828:
682:
628:
2027:
2014:
1870:
912:
908:
867:
812:
759:
687:
679:
613:
566:
562:
470:
454:
412:
298:
187:
182:
172:
1930:
National Register of Historic Places listings in Grand Canyon National Park
1875:
1360:
Quest for the Pillar of Gold: the Mines & Miners of the Grand Canyon.
1308:
Pseudo-organic structures from the Precambrian Bass limestone in Arizona.
976:
900:
840:
786:
675:
631:
597:
1421:
1410:
1227:
Bloch, JD, JM Timmons, GE Gehrels, LJ Crossey, and KE Karlstrom (2006)
944:
916:
856:
836:
824:
747:
693:
558:
515:
486:
450:
404:
56:
723:
limestone of the Bass Formation is intimately interbedded with coarse
998:
936:
863:
816:
778:
623:
551:
535:
523:
504:
474:
416:
408:
314:
63:
1375:
Circular no. 7706. U.S. Bureau of Mines Information, Washington, DC.
1266:
Ep-Archean and Ep-Algonkian erosion surfaces, Grand Canyon, Arizona.
904:
832:
805:
692:
547:
522:
or calcsilicate dominated mineral assemblages of adjacent strata.
337:
329:
240:
1002:
859:
820:
478:
301:
layers form steep treads. In general, the Bass Formation in the
1505:
1501:
887:
766:
that deposited the Tapeats Sandstone and other members of the
1498:, National Park Service, Grand Canyon National Park, Arizona.
1454:, National Park Service, Grand Canyon National Park, Arizona.
1215:
Middle and late Proterozoic Grand Canyon Supergroup, Arizona.
1185:. Geological Society of America Bulletin. 117(11/12):1573–95.
758:
as topographic highs, (today seen as ancient & weathered
1460:
Geologic Map and Section of the Shinumo Quadrangle, Arizona.
1284:
Journal of the Palaeontological Society of India. 20:170–77.
438:
in 1914 for Bass Canyon, where it is typically exposed. The
253:-(orange), sitting on Granite Gorge-(Upper Inner Gorge, the
388:, about 113 to 150 m (371 to 492 ft) thick; the
1426:
1415:
1354:
1352:
1099:
Bulletin no. 549, US Geological Survey, Reston, Virginia.
951:– constrain the age of the Bass Formation and associated
592:
have been reported from the Bass Formation. They include
526:
from one of these volcanic ash beds has been dated using
1362:
Grand Canyon Association, Grand Canyon, Arizona. 112 pp.
911:
exposure found in the upper part of the Bass Formation.
384:. The Unkar Group is overlain in ascending order by the
1125:
1097:
The Shinumo quadrangle, Grand Canyon district, Arizona.
1295:
Pre-Metazoan evolution and the origins of the Metazoa.
1268:
Geological Society of America Bulletin. 51(8):1235–69.
1123:
1121:
1119:
1117:
1115:
1113:
1111:
1109:
1107:
1105:
947:
rocks, and thermochronologic studies of the underling
1146:
Geological Society of America Bulletin. 93(8):681–99.
1247:
1245:
1243:
1241:
1239:
1237:
1177:
1175:
1173:
1171:
1169:
1167:
1165:
964:
the Bass Formation lies between 1,660 and 1,250 Ma.
831:; the jellyfish are either gas escape structures or
392:, about 1,900 m (6,200 ft) thick; and the
1912:
1884:
1863:
1832:
1784:
1600:
1539:
1318:
1316:
453:of which dolomite is the predominant rock type and
231:
223:
218:
208:
198:
193:
168:
158:
153:
145:
131:
121:
113:
103:
93:
21:
1276:
1274:
1358:Billingsley, GH, EE Spamer, and D Menkes (1997)
1231:Journal of Sedimentary Petrology. 76(9):1106–19.
1478:Timmons, M. K. Karlstrom, and C. Dehler (1999)
1427:mindat.org – the mineral and locality database.
1416:mindat.org – the mineral and locality database.
890:accumulated in the western Grand Canyon, while
1338:
1336:
855:from the west. The Hotauta Member consists of
750:of the Unkar Group left resistant beds of the
1517:
1346:Arizona Bureau of Mines Bulletin. 180:303–11.
1209:
1207:
1197:
1195:
1193:
1191:
309:-rocks dip northeast (10°–30°) toward normal
88:Stromatolites in Bass Limestone, Grand Canyon
8:
1925:List of trails in Grand Canyon National Park
1091:
1089:
323:The Bass Formation is the basal part of the
16:Lithostratigraphic unit found in Arizona, US
1475:, U.S. Geological Survey, Reston, Virginia.
1466:, U.S. Geological Survey, Reston, Virginia.
1326:In WJ Breed and EC Roat, eds., pp. 170–76,
469:The Bass Formation consists of interbedded
262:Cheops Pyramid (prominence), Grand Canyon (
1524:
1510:
1502:
1486:Boatman's Quarterly Review. vol. 12, no. 1
654:The base of the Bass Formation is a major
82:
18:
1405:U.S. Geological Survey, Reston, Virginia.
1650:Grand Canyon–Parashant National Monument
1373:Chrysotile-asbestos deposits of Arizona.
697:Bass Formation sitting on Granite Gorge.
425:
1439:Overview of the Grand Canyon Supergroup
1344:Mineral and water resources of Arizona.
1129:Hendricks, JD, and GM Stevenson (2003)
1085:
939:from an ash bed in the Bass Formation,
738:and faulted Unkar Group is a prominent
734:and Bass Formation and the rest of the
396:, about 60 m (200 ft) thick.
1496:(Grand Canyon Geology Training Manual)
2072:Geography of Coconino County, Arizona
1131:Grand Canyon Supergroup: Unkar Group.
811:Various types of other fossils, i.e.
7:
1894:Powell Geographic Expedition of 1869
1494:Learning to Read the Pages of a Book
305:region and associated strata of the
2057:Natural history of the Grand Canyon
1899:1956 Grand Canyon mid-air collision
1452:Grand Canyon National Park, Arizona
320:intrude across the Bass Formation.
481:sandstone, prominent interbeds of
364:(high resolution expandable photo)
149:121 to 341 feet (37 to 104 m)
14:
1444:Mathis, A., and C. Bowman (2007)
907:, and other evidence of periodic
518:assemblage that differs from the
1986:Grand Canyon: The Hidden Secrets
1920:Grand Canyon Backcountry Camping
1310:Fieldiana Geology. v. 23(1):1–9.
1069:Geology of the Grand Canyon area
1053:
1039:
1979:The Man Who Walked Through Time
1441:, Grand Hikes, Bob's Rock Shop.
1420:Jorge, R, and T. Larry (2013b)
1409:Jorge, R, and T. Larry (2013a)
1142:Elton, DP, and EH McKee (1982)
2052:Geologic formations of Arizona
1993:Grand Canyon: A Different View
1904:Grand Canyon Airlines Flight 6
1464:National Geologic Map Database
1342:Shride, AF (1969) Asbestos In
1280:Ford, TD, and WJ Breed (1975)
577:(river mile 77) and along the
1:
1572:Grand Canyon Village, Arizona
442:has been reclassified as the
285:that outcrops in the eastern
266:region, Bright Angel Canyon)
247:multiple & thinly layered
1645:Grand Canyon Forest Reserve
1328:Geology of the Grand Canyon
2088:
1562:Grand Canyon National Park
870:gravel indicates that the
2067:Precambrian United States
1393:Colorado Plateau Archives
847:Depositional environments
795:Fenton & Fenton, and
646:on which it accumulated.
81:
26:
1935:Grand Canyon Conservancy
1322:Billingsley, GH. (1974)
730:The contact between the
710:cliffs above orange-red
702:-Cheops Pyramid region (
291:Coconino County, Arizona
2062:Mesoproterozoic geology
1766:Uinkaret volcanic field
1655:Grand Canyon Supergroup
1547:Black Suspension Bridge
1293:Cloud, PE., Jr. (1968)
804:environment close to a
742:, which is part of the
602:cone-in-cone structures
401:Grand Canyon Supergroup
297:layers form risers and
1973:(2017 children's book)
1491:Timmons, S. S. (2003)
1324:Mining in Grand Canyon
715:
714:, upon Bass Formation.
590:sedimentary structures
431:
365:
350:, a few sections near
335:
267:
1999:Grand Canyon Escalade
1963:A Bigger Grand Canyon
1819:Little Colorado River
1557:Grand Canyon Escalade
949:Vishnu Basement Rocks
696:
612:, recrystallization,
429:
421:Vishnu Basement Rocks
356:Vishnu Basement Rocks
341:
333:
258:Vishnu Basement Rocks
244:
136:Vishnu Basement Rocks
2028:36.1080°N 112.1209°W
1640:Grand Canyon Caverns
1630:Ericameria arizonica
1567:Grand Canyon Skywalk
1457:Noble, F. L. (1914)
1264:Sharp, R. P. (1940)
1022:Gila County, Arizona
1007:contact-metamorphism
880:marine transgression
764:marine transgression
740:angular unconformity
459:Hotauta Conglomerate
274:, also known as the
98:Geological formation
2024: /
1670:Sixtymile Formation
1665:Nankoweap Formation
1635:Esplanade Sandstone
1472:Geologic Unit: Bass
1431:Keller, B., (2012)
1371:Stewart, LA (1955)
1306:Nitechi, MH (1971)
933:uranium-lead dating
793:Collenia symmetrica
746:. The differential
583:North Kaibab Trails
528:Uranium-lead dating
394:Sixtymile Formation
386:Nankoweap Formation
28:Stratigraphic range
2033:36.1080; -112.1209
1941:Grand Canyon Suite
1824:Bright Angel Creek
1754:Bright Angel Shale
1610:Agave phillipsiana
1434:The Bass Limestone
1213:Elston, DP (1989)
1074:Great Unconformity
941:argon–argon dating
744:Great Unconformity
716:
600:covered surfaces;
432:
366:
336:
268:
2007:
2006:
1948:Desert Wonderland
1734:Redwall Limestone
1709:Hyaloclastite Dam
1685:Shinumo Quartzite
1582:Marble Canyon Dam
1552:Bridge Canyon Dam
1488:, pp. 29–32.
1469:Stamm, N. (2011)
1398:Anonymous (2011)
1095:Noble, LF (1914)
1018:Salt River Canyon
984:Powell expedition
843:of algal origin.
797:Collenia frequens
756:Shinumo Quartzite
732:Tapeats Sandstone
708:Shinumo Quartzite
374:Shinumo Quartzite
360:Tapeats Sandstone
249:) below colorful
239:
238:
138:on major erosion
2079:
2039:
2038:
2036:
2035:
2034:
2029:
2025:
2022:
2021:
2020:
2017:
1771:Vasey's Paradise
1704:Hermit Formation
1526:
1519:
1512:
1503:
1400:"Bass Limestone.
1376:
1369:
1363:
1356:
1347:
1340:
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1063:
1058:
1057:
1049:
1044:
1043:
1042:
972:The presence of
511:, and a diverse
348:Komo Point Trail
245:Bass Formation (
86:
77:
66:
59:
52:
45:
39:
19:
2087:
2086:
2082:
2081:
2080:
2078:
2077:
2076:
2042:
2041:
2032:
2030:
2026:
2023:
2018:
2015:
2013:
2011:
2010:
2008:
2003:
1966:(1998 painting)
1908:
1880:
1859:
1840:Harvey Butchart
1828:
1785:Bodies of water
1780:
1776:Vulcan's Throne
1694:Grand Staircase
1620:Cardenas Basalt
1596:
1535:
1530:
1388:anonymous (nd)
1385:
1380:
1379:
1370:
1366:
1357:
1350:
1341:
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1103:
1094:
1087:
1082:
1059:
1052:
1045:
1040:
1038:
1035:
970:
961:Cardenas Basalt
929:
849:
776:
752:Cardenas Basalt
698:
652:
614:stylolitization
467:
382:Cardenas Basalt
363:
280:Mesoproterozoic
261:
186:
181:
176:
89:
76:
75:
74:
73:
68:
64:
61:
57:
54:
50:
47:
43:
37:
36:
35:
32:Mesoproterozoic
17:
12:
11:
5:
2085:
2083:
2075:
2074:
2069:
2064:
2059:
2054:
2044:
2043:
2005:
2004:
2002:
2001:
1996:
1989:
1982:
1975:
1967:
1959:
1951:
1944:
1937:
1932:
1927:
1922:
1916:
1914:
1910:
1909:
1907:
1906:
1901:
1896:
1890:
1888:
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1879:
1878:
1873:
1867:
1865:
1861:
1860:
1858:
1857:
1852:
1847:
1845:Colin Fletcher
1842:
1836:
1834:
1830:
1829:
1827:
1826:
1821:
1816:
1811:
1810:
1809:
1799:
1794:
1792:Colorado River
1788:
1786:
1782:
1781:
1779:
1778:
1773:
1768:
1763:
1761:Toroweap Fault
1758:
1757:
1756:
1746:
1741:
1736:
1731:
1726:
1721:
1716:
1711:
1706:
1701:
1696:
1691:
1690:
1689:
1688:
1687:
1682:
1680:Bass Formation
1672:
1667:
1662:
1652:
1647:
1642:
1637:
1632:
1627:
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1606:
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1383:External links
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1061:Geology portal
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1047:Arizona portal
1034:
1031:
969:
968:Asbestos mines
966:
928:
925:
848:
845:
775:
772:
651:
648:
618:silicification
610:dolomitization
606:graded bedding
571:Colorado River
509:graded-bedding
466:
463:
444:Bass Formation
440:Bass Limestone
436:Bass Limestone
419:that comprise
283:rock formation
276:Bass Limestone
272:Bass Formation
237:
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117:Hotauta Member
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62:
55:
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24:
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22:Bass Formation
15:
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1933:
1931:
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1740:
1739:Tanner Graben
1737:
1735:
1732:
1730:
1727:
1725:
1722:
1720:
1719:Kanab Plateau
1717:
1715:
1712:
1710:
1707:
1705:
1702:
1700:
1699:Hakatai Shale
1697:
1695:
1692:
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1651:
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1638:
1636:
1633:
1631:
1628:
1626:
1625:Dox Formation
1623:
1621:
1618:
1616:
1615:Bat Cave mine
1613:
1611:
1608:
1607:
1605:
1603:
1599:
1593:
1592:Phantom Ranch
1590:
1588:
1585:
1583:
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1397:
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1355:
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1313:
1309:
1303:
1300:
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1234:
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1126:
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1120:
1118:
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1102:
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1062:
1056:
1051:
1048:
1037:
1032:
1030:
1027:
1023:
1019:
1015:
1010:
1008:
1004:
1000:
996:
992:
991:Tapeats Creek
987:
985:
981:
978:
975:
967:
965:
962:
958:
954:
950:
946:
943:of overlying
942:
938:
934:
926:
924:
922:
918:
914:
910:
906:
902:
898:
893:
892:stromatolites
889:
885:
881:
877:
873:
872:conglomerates
869:
865:
861:
858:
854:
846:
844:
842:
838:
834:
830:
826:
822:
818:
814:
809:
807:
803:
798:
794:
790:
788:
783:
782:stromatolites
780:
773:
771:
769:
765:
761:
757:
753:
749:
745:
741:
737:
733:
728:
726:
722:
721:stromatolitic
713:
712:Hakatai Shale
709:
705:
701:
695:
691:
689:
684:
681:
678:developed by
677:
671:
669:
668:Shinumo Creek
663:
661:
657:
649:
647:
645:
641:
635:
633:
630:
625:
621:
619:
615:
611:
607:
603:
599:
595:
591:
588:A variety of
586:
584:
580:
576:
572:
568:
564:
560:
557:
553:
549:
545:
541:
537:
531:
529:
525:
521:
517:
514:
510:
506:
502:
498:
494:
492:
488:
484:
480:
476:
472:
464:
462:
460:
456:
452:
449:
445:
441:
437:
428:
424:
422:
418:
414:
410:
406:
402:
397:
395:
391:
387:
383:
379:
378:Dox Formation
375:
371:
370:Hakatai Shale
361:
357:
353:
352:Granite Gorge
349:
345:
340:
332:
328:
326:
321:
319:
316:
312:
308:
304:
300:
296:
292:
288:
284:
281:
277:
273:
265:
259:
256:
252:
251:Hakatai Shale
248:
243:
234:
230:
226:
222:
217:
214:
213:United States
211:
207:
204:
201:
197:
192:
189:
184:
179:
174:
171:
167:
164:
161:
157:
152:
148:
144:
141:
137:
134:
130:
127:
126:Hakatai Shale
124:
120:
116:
112:
109:
106:
102:
99:
96:
92:
85:
80:
67:
60:
53:
46:
33:
29:
25:
20:
2009:
1991:
1984:
1977:
1971:Grand Canyon
1970:
1961:
1955:Grand Canyon
1954:
1946:
1939:
1807:Havasu Falls
1802:Havasu Creek
1744:Temple Butte
1729:Prospect Dam
1724:Newton Butte
1679:
1587:Maswik Lodge
1533:Grand Canyon
1493:
1480:
1471:
1459:
1446:
1433:
1422:
1411:
1404:
1401:
1372:
1367:
1359:
1343:
1327:
1323:
1307:
1302:
1294:
1289:
1281:
1265:
1260:
1252:
1228:
1223:
1214:
1182:
1156:
1151:
1143:
1138:
1130:
1096:
1014:Sierra Ancha
1011:
988:
971:
930:
897:ripple marks
853:transgressed
850:
823:trails, and
810:
808:is lacking.
796:
792:
785:
777:
729:
717:
703:
672:
664:
656:unconformity
653:
644:paleosurface
636:
622:
594:ripple marks
587:
579:South Kaibab
575:Hance Rapids
532:
530:techniques.
501:Volcanic ash
499:
495:
491:stromatolite
483:conglomerate
468:
458:
443:
439:
435:
433:
398:
367:
322:
303:Grand Canyon
287:Grand Canyon
275:
271:
269:
254:
246:
235:Noble (1914)
219:Type section
203:Grand Canyon
178:conglomerate
140:unconformity
38:1250 Ma
2031: /
2019:112°07′15″W
1957:(1958 film)
1850:Kenton Grua
1814:Kanab Creek
1749:Tonto Group
1714:Isis Temple
1675:Unkar Group
1660:Chuar Group
1577:Kolb Studio
957:Precambrian
953:Unkar Group
903:, oxidized
829:concretions
768:Tonto Group
700:Isis Temple
640:Isis Temple
573:level near
561:, and micro
556:plagioclase
550:, granite,
465:Description
448:sedimentary
390:Chuar Group
325:Unkar Group
307:Unkar Group
264:Isis Temple
227:Bass Canyon
108:Unkar Group
51:Proterozoic
2046:Categories
2016:36°06′29″N
1855:John Hance
1797:Deer Creek
1540:Facilities
1080:References
1026:serpentine
1020:region of
974:chrysotile
884:diagenesis
802:intertidal
760:monadnocks
704:Utah Flats
683:weathering
629:chrysotile
563:pegmatites
413:pegmatites
344:Komo Point
1871:Havasupai
913:Evaporite
909:subaerial
901:mudcracks
868:quartzite
841:oncolites
813:jellyfish
806:shoreline
791:Walcott,
688:peneplain
680:subaerial
627:produced
567:quartzite
520:carbonate
471:sandstone
455:limestone
354:of black
299:argillite
224:Named for
188:limestone
183:argillite
173:sandstone
154:Lithology
146:Thickness
122:Underlies
114:Sub-units
1876:Hualapai
1033:See also
997:, green
995:chlorite
977:asbestos
917:mudflats
825:bivalves
787:Collenia
706:), with
676:regolith
660:basement
650:Contacts
632:asbestos
624:Basaltic
598:mudcrack
559:crystals
513:silicate
409:gneisses
405:granites
315:basaltic
295:dolomite
255:blackish
232:Named by
194:Location
163:dolomite
132:Overlies
1913:Related
1602:Geology
945:igneous
937:zircons
864:gravels
857:fluvial
837:bivalve
817:sponges
774:Fossils
748:erosion
725:clastic
542:-sized
524:Zircons
516:mineral
487:breccia
477:), and
417:schists
278:, is a
209:Country
159:Primary
104:Unit of
72:↓
58:Archean
1886:Events
1864:Tribes
1833:People
1001:, and
999:garnet
921:deltas
919:, and
905:shales
876:Marine
789:undosa
779:Fossil
736:folded
616:, and
552:quartz
544:clasts
540:cobble
536:pebble
505:tephra
475:arkose
451:strata
415:, and
380:, and
311:faults
199:Region
185:, and
980:veins
860:sands
833:algal
548:chert
479:silty
342:From
318:sills
169:Other
1003:talc
931:The
862:and
821:worm
754:and
581:and
399:The
270:The
94:Type
65:Had.
44:Pha.
1218:pp.
935:of
927:Age
888:mud
546:of
538:to
260:).
2048::
1484:.
1450:,
1437:,
1351:^
1335:^
1315:^
1273:^
1236:^
1206:^
1190:^
1164:^
1104:^
1088:^
899:,
819:,
815:,
690:.
620:.
596:;
585:.
554:,
423:.
411:,
407:,
376:,
372:,
346:/
327:.
289:,
180:,
175:,
34:,
30::
1525:e
1518:t
1511:v
1016:-
473:(
362:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
