Paleozoic Outcrops in Mojave Desert

Donald Kenney (
Last Update: Sat Jun 25 06:46:43 2011


Arizona -- Devonian

This is one of a series of "site descriptions" that I will be creating for classic fossil sites over the coming years. This 'description' seems to consist pretty much entirely of notes that haven't yet been worked up into a real description.

The Site(s)

Best Guess 35.247319,-111.587083 This is a slightly educated guess based on satellite images and the knowledge that the fossil outcrop is half way or more up the Eastern side of Mt Eldon. Note that this location would be about 900 feet above the base of the mountain, 900 feet below the top of the local slope, and 1100 feet below the actual highest peak.

The fish fossils -- both plates and teeth -- are said to be most common in a grey thin bedded limestone about 10 meters above the base of the outcrop



An uplifted igneous dome with some uplifted Paleozoic beds plastered on the sides.

Other sites

"Flagstaff","Coconino","AZ","S 8 km at Lake Mary on NW side of lake","Permian","Kaibab","invertebrates,fish(ganoid)(teeth,spines)","AZ0061","35.1825,-111.6611MCU","|",,, "Flagstaff","Coconino","AZ","near Bottomless Pit 2 km E of Flagstaff Country Club in porous buff colored Limestone","Permian","Kaibab","fish(ganoid)-teeth;sharks-teeth;","AZ0062","35.1825,-111.6611MCU","|",,, "Grand Canyon","Coconino","AZ","About 15 isolated thin deposits of Devonian Temple Butte Formation contain fish fossils at the base of the Redwall Limestone","Devonian","Temple Butte","vertebrates-fish","AZ0071","36.0544,-112.1386MCU","|",,, "Grand Canyon","Coconino","AZ","In Devonian Limestone at 15 locations along base of Redwall Limestone","Devonian""vertebrates-fish","AZ0073","36.0544,-112.1386MCU","|", "Grand Canyon","Coconino","AZ","along Chuar Creek Valley,Sapphire Canyon,Yak Trail","Devonian","Temple Butte","Arthrodira-fragments-Bothriolepis,Holoptychius","AZ0081","36.0544,-112.1386MCU","|",,, "Grand Canyon","Coconino","AZ","fossiliferous buff and gray Limestone above Coconino Sandstone","Corals,Mollusks,Echinoids,sharks-teeth","AZ0082","36.0544,-112.1386MCU","|", "Grand Canyon","Coconino","AZ","on S rim in campground area","Permian","Kaibab","vertebrates-fish","AZ0083","36.0544,-112.1386MCU","|",,, "Gray Mountain","Coconino","AZ","56 km E of Flagstaff at Rimmy Jim Tank in nw1/4s17t17nr9s in Limestone. Rimmy Jim tank is about 4km S of the town of Gray Mountain accessible from a side road off of US89 (PLSS of the tank is S18T27NR9E)","Permian","Kaibab","vertebrates-fish(ganoid)-teeth;;invertebrates","AZ0059","35.7161, -111.4726,nw1/4s17t27nr9e?","|", "Sedona","Coconino","AZ","S on AZ179 1.75 km E one km in scattered boulders|very good fish fossils","Permian","Kaibab","fish fossils","AZ0103","34.8606,-111.8194MCU","|",,, "Sedona","Coconino","AZ","in isolated porous reddish boulders of Limestone. 1 km E of AZ179 2 km S|very good fish fossils","Permian","Kaibab","fish fossils,invertebrates","AZ0104","34.8606,-111.8194MCU","|",,, "Shinarump","Coconino","AZ""Triassic","Chinle","Reptilia-bones-Hesperosuchus?","AZ0105","36.9819,-112.4300MCU","|", "Sycamore Pass","Coconino","AZ""Permian","Coconino","trackway-Laoporus","AZ0106","34.9275,-111.9947MCU","|", "Tucsyan","Coconino","AZ","in road cuts on Grand Canyon Road (some outside park)","Pennsylvanian""echinoids,trilobites,brachiopods,gastropods","AZ0107""|", "Tucsyan","Coconino","AZ","in road cuts on road to Grand Canyon","Permian","Kaibab","gastropods,Brachiopods,echinoids,trilobites","AZ0108""|",,, "Walnut Canyon","Coconino","AZ","13 km SE of Flagstaff in roadcuts and natural exposures","fossils(abundant)","AZ0109","34.2992,-111.4875MCU","|", "Walnut Canyon","Coconino","AZ","6 km N","mollusks,bivalves-Plagioglypta[?],Nuculopsis,Pecten,bryozoa,cephalopods,trilobites-pygidia","AZ0110","Original is 'Plagioglypts' which probably a typo. 'Plagioglypta' is my best guess. But it's a scaphopod,not a pelecypod. 'Plagioglyptus',also a scaphopod,is another possibility""34.2992,-111.4875MCU","|", "Walnut Canyon","Coconino","AZ","area exposures 1/2 km E of Walnut Canyon NM","fossils(abundant)-Dictyoclostus,Dentalium,Marginifera,Bellerophon","AZ0111","34.2992,-111.4875MCU","|", "Walnut Ranger Cabin","Coconino","AZ","6 km S of old Ranger Cabin at Walnut Bend in Walnut Canyon","Dictyoclostus,Plagioglypta[?],mollusks","AZ0112","Plagioglypta originally entered as Plagioglypts","|",,, "Walnut Ranger Cabin","Coconino","AZ","below old Ranger Cabin","Dictyoclostus,Dentalium,Chonetes,Pecten,Aviculopecten,sponges","AZ0113""|", "Whitehorse Hills","Coconino","AZ","s12t23nr6e 35.3904N,-111.7105W","Mississippian","Redwall","corals,brachiopods,crinoids","AZ0114","35.3904,-111.7105,s12t23nr6e","|", "Winona","Coconino","AZ","Fossil fresh water shells in area breaks","invertebrates-mollusks","AZ0115","35.2050,-111.4075MCU","|", "-","Coconino,Navajo","AZ","In outcrops of the Glen Canyon Group|{7}","Jurassic","Glen Canyon Group","vertebrates-Reptilia-dinosaurs-Dilophosaurus,dinosaurs-tracks","AZ0119","35.1892,-111.3772MCU","|",,, "-","Coconino,Navajo","AZ","Kayenta-Wingate group sandstones","Jurassic","Kayenta|Wingate","vertebrates-Reptilia-dinosaurs-tracks","AZ0118","35.1892,-111.3772MCU","|",,, "-","Coconino,Navajo","AZ""Cretaceous","Mesaverde Group","Coal,mollusks,plants-wood,leaves","AZ0117","35.1892,-111.3772MCU","|", "-","Gila","AZ","2 km N of AZ177 US77 junction at S end of Dripping Springs Mountain then 27 k7 km N in roadcuts","Paleozoic""fossils(abundant)","AZ0136""|", "-","Gila","AZ","2 km N of AZ177 US77 junction at S end of Dripping Springs Mountain then 28 km N","Devonian-Mississippian","Martin|Escabrosa","fossils","AZ0137""|",,, "Globe","Gila","AZ","5 km NW on S side of Pinal Creek","Devonian""invertebrates,fish-teeth;","AZ0122","33.3950,-110.7761MCU","|", "Globe","Gila","AZ","at S side of Pinal Creek 5 km NW","Devonian","Martin","invertebrates,fish-teeth;","AZ0123","33.3950,-110.7761MCU","|",,, "Payson","Gila","AZ","30 km N on Heber-Young Rd in floor of Tonto Creek as well as area roadcuts,others","Arthrodira-plates,good invertebrates","AZ0127","34.2667,-111.3150MCU","|", "Payson","Gila","AZ","35.4 km N in floor of Tonto Creek on the Heber-Young Rd","Devonian""invertebrates,Arthrodira-plates","AZ0128","34.2667,-111.3150MCU","|", "Payson","Gila","AZ","AZ87 2 km N of East Verde bridge between Payson and Pine","Devonian""invertebrates,Arthrodira-plates","AZ0129","34.2667,-111.3150MCU","|", "Payson","Gila","AZ","in roadcut 2 km N of East Verde River Bridge on AZ87 between Payson and Pine","Devonian""Arthrodira-plates,invertebrates(abundant)","AZ0131","34.2667,-111.3150MCU","|", "Camp Apache","Maricopa?","AZ","in limestone","Pennsylvanian""Fish tooth","AZ0149""|", "Colossal Cave","Pima","AZ","S of the County Park","Paleozoic""fish-teeth;,others","AZ0194","32.0650,-110.6303SCU","|", "Colossal Cave","Pima","AZ","to S of park in Paleozoic beds","vertebrates-fish-sharks-teeth;others","AZ0195","32.0650,-110.6303SCU","|", "Helmet Peak","Pima","AZ","Off Twin Buttes Rd S of San Xavier Mission in Limestone","Permian","Concha","fish(ganoid)-teeth;,invertebrates","AZ0200","31.9667,-111.0808MCU","|",,, "Helmet Peak","Pima","AZ","S of San Xavier Mission","Permian","Concha","fish-teeth;","AZ0201","31.9667,-111.0808MCU","|",,, "Oracle","Pima","AZ","14 km S on Oracle-Mt Lemmon Rd in Peppersauce Canyon in brown/ red sandy lenses","Devonian","Martin","vertebrates-fish","AZ0206","32.6186,-110.7889MCU","|",,, "Picacho de Calera Hills","Pima","AZ","29 km NW of Tucson in quarry of Arizona Portland Cement Company and in regional exposures. Satellite photos raise the possibility that the material has been quarried out","fucoids,brachiopods,trilobites(Asaphiscus),fish-teeth;,Goniatites,stromatoporoids,corals,fusilinids","AZ0208","AZ208,AZ0226,AZ0227 basically same site","|",,, "Tucson","Pima","AZ","W at Picacho de Calera 9.6 km W or Avra Valley exit for I10 S on Sandarino Rd. S 2 km to Twin Peaks Rd to site. in brown Sandstone on W side of E hill. Recent satellite photos make it appear that the entire Eastern hill has been quarried away (it still appears on terrain maps though)","Cambrian""invertebrates-cephalopods","AZ0226","AZ208,AZ0226,AZ0227 basically same site""31.9653,-110.7750MCU","|", "Tucson","Pima","AZ","W at Picacho de Calera 9.6km W or Avra Valley exit for I10 S on Sandarino Rd. S 2 km to Twin Peaks Rd to site. in brown Sandstone on W side of E hill Recent satellite photos make it appear that the entire Eastern hill has been quarried away (it still appears on terrain maps though)","Devonian","Picacho de Calera","fish-teeth;,trilobites,Invertebrates","AZ0227","AZ208,AZ0226,AZ0227 basically same site""31.9653,-110.7750MCU","|",,, "Galiuro Mountains","Pinal","AZ","In Paleozoic limestones and dolostones on N flank of Little Table Mountain SE1/4S15T7R18E 3 km N of crest along W side of Virgus Canyon (T7S 32.8208 110.4873 2km E of Table Mountain)","Mississippian""corals(abundant),crinoids(abundant)-fragments,teeth-Psephodus;brachiopods,gastropods,rarely blastoidea","AZ0231","32.8208,-110.4873, SE1/4S15T7R18E","|",,, "Superior","Pinal","AZ","E on first Ridge in bone bed breccia in sandstone and in overlying limestone","Devonian","Martin","Arthrodira-plates,fish-teeth;,conodonts","AZ0238","33.2939,-111.0956MCU","|",,, "Superior","Pinal","AZ","In bone breccia in base of Sandstone on first Ridge E of town","Devonian","Martin","vertebrates-fish-Arthrodira-plates,teeth,conodonts","AZ0239","33.2939,-111.0956MCU","|",,, "Ash Fork","Yavapai","AZ","30.5 km S in quarry on US89","Devonian""Arthrodira-plates","AZ0241","35.2250,-112.4833MCU","|", "Jerome","Yavapai","AZ","in quarried roadcut 15.4 km W on US89 Alt","Devonian""vertebrates-fish-Arthrodira","AZ0248","large Arthrodira-plates to 40cm in length""34.7489,-112.1131MCU","|", "Jerome","Yavapai","AZ","on US89 17 km W in large quarried roadcut both red and grey limestones","Devonian""vertebrates-fish-Arthrodira","AZ0249","Large Arthrodira-plates to nearly 40cm""34.7489,-112.1131MCU","|",

U.S. alternate 89. Many of the roadcuts on both sides of the mountain contain good fossils. Fish plates are found in both a red shaley limestone and a massive grey limestone. The quarried roadcut and the talus slope below the road grade are the major collecting areas. Cross-sections of the arthrodire plates that measure 1 1/2 inches thick and 15 inches long are abundant. GILA COUNTY The Martin Formation crops out on the south side of Pinal Creek, three miles northwest of Globe, contains many Devonian invertebrates and fish teeth. GILA COUNTY Located in a roadcut one mile north of the East Verde bridge on Arizona Route 87 between Payson and Pine, arthrodire plates are common in the sandstones, dolomites and interbedded shales. Devonian age invertebrates are common. COCONINO COUNTY 6.3 miles north of Hieroglyphic point overlook on Highway 77, basal, dark, siliceous shaley Devonian beds contain important fossil plants. For about one mile north on this road, roadcuts can be highly fossiliferous.


Formations (youngest first)


Stratigraphic Section



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