Synthesis of late Paleozoic and Mesozoic eolian deposits of the ...

More documents

Recommendations

Info

34 the southern Monument Uplift and across the northern Kaibab Uplift. Nothing is known about the erg to the west and north of its area of outcrop in southeastern Utah. We offer three untested hypotheses concerning its margins in these direc- tions: (1) the eolian deposits thin to an erosional or depositional edge; (2) they merge with the Navajo Sandstone because of northwestward pinch-out of the intervening Kayenta Formation; and (3) the eolian sandstones undergo facies change with fluvial and sabkha redbeds as can be documented along its present southwestern margin; our discussion of the Navajo-Nugget Sandstone in the next section favors the third hypothesis. The southwestern margin of the Wingate is exposed along a line of cliffs that trend from near Holbrook, Arizona to Zion National Park, Utah. Figure 16 shows restored cross-sections across the erg margin. Edwards (1985) documented fluvial- eolian interactions in north-central Arizona and work in progress by Lars Clemmensen and Henrik Olsen of the University of Copenhagen in con- junction with Blakey is studying the erg margin along the Vermilion Cliffs. These studies docu- ment an initial erg progradation southwest to a line from north-central Arizona to south-central Utah (Fig. 16). Fluvial deposits, chiefly of ephemeral sheet-flood and stream-flood origin, en- croached upon and reworked the erg margin. The fluvial deposits, the Dinosaur Canyon Member of the Moenave Formation, extended as far north- eastward as a line from the Defiance Plateau in Arizona to west of the Circle Cliffs in Utah (Figs. 15 and 16). Most stratigraphic work has placed the lower southwest extension of the erg in the Wingate Sandstone and the interval of alternating fluvial and eolian deposition in the Dinosaur Canyon Member of the Moenave Formation. The Wingate Sandstone is in need of additional sedimentologic and stratigraphic study. Little is known about regional sedimentologic trends and history of erg development. The isopachs (Fig. 15) and cross sections (Fig. 16) show some relations to regional syn-depositional tectonic patterns (Blakey, this volume), especially the southern margin, which closely parallels the Zuni lineament of Kelley (1955). Apparently the northeast margin of northwesterly flowing streams in the Moenave Formation was somehow influenced by this fine. Lower Jurassic H eolian deposits Eolian strata of late Early Jurassic age depicted on the data base and isopach maps (Figs. 17 and 18) probably formed the largest eolian deposits in North America. These rocks include such well- known units as the Aztec Sandstone (Nevada and southeastern California), the Glen Canyon Sand- stone (northwestern Colorado and northeastern Utah), the Navajo Sandstone (northern Arizona, western Colorado, southern and central of Utah), and the upper member of the Nugget Sandstone (southeastern Idaho, northern Utah and Wyo- ming). Eolian strata in southern Arizona that are thought to correlate at least approximately with these units are included in several formations, each of which is restricted to one or a few of the mountain ranges in the Basin and Range Province. These includes the Ali Molina, Mount Wrightson, and Sil Nakya Formations, the Cobre Ridge Tuff, and the Ox Frame Volcanics (Bilodeau and Keith, 1986). Data used in preparation of the isopach map are included in Table 5 and the distribution of data points is shown on Fig. 17. These beds are here considered late Early Jurassic in age (Pliens- bachian and Toarcian Ages; Peterson and Pipiringos, 1979). Not included in this study are quartzites of Early Jurassic age in the southern part of western Nevada that may also be eolian and that may correlate with late Early Jurassic eolian units farther east in the Western Interior. Although highly metamorphosed, cross-bedding in the quartzites can still be recognized even though finer details such as grading, ripple cross-laminations, details of the laminations, and grain shape have been largely or entirely obliterated, making it dif- ficult to find conclusive evidence of the mode of deposition. Proffett and Dilles (1984) considered Jurassic quartzites (their quartzitic sandstone) of the Singatsee Range (sect. 27, T13N, R24E, Lyons County, Nevada) eolian in origin but a field check revealed only poorly suggestive evidence such as the moderately large thickness (as much as 1.5 m) of a small number of sets and the relatively pure
460 41 ° 36' 31 = 117 ° 112 ° 107 ° 102 ° ' ¢ ' , / : L ¢'-"1 ~ -'-, r / _,-L.~ h / : ,~ "-~--f ~----f \ L If ,-J" ' ~ L_~ I I- -I---- A-.. [ / ~ / -i / ~-" .-~_L --r--/-------- - '~------~----'-I ! J I- r-- "I_ I : ! ~----------\~---k~, L"--x~-~'_ ~__~.~.z----~----l-~---~f-~--l-----'---F b~ ! ! I ~~.,~,~--~":,~,'.~; ! ") \ / I I- 1 " ~ ~ ' |- . ~ ~.~_~. _ "I .~ ~ , , 1 .--H__ \ ~WE~ ~UmASS,C~ ), L I "T-' I--~"~ o" H I i___F--~-n / F • ---- j ,~ ,' I ,--- -- I ____J_2 t U'-~~:A-4' ..... ~-'__L,_~q~--mr , \ I • ~ ." -. r I \ ~__. L~.~____+_r .~_~ .44 e9 4 e81 ~_~.--~_~ , I h--~ ~--~- T-q \ ,'---" .,,,~ -- ~--',-.,~,..::::..o,-- T ~- ~ 1 \ . I .,,o I ~ ,,~. I,~.,, IO..,;.,, I ~, ~ / ~'-----~ ~' ) 19 294 I I - x _ I , .,, ~,.. / i x Surface~sectionL~ [---""~"--~ t'~-- ' :~?o~\ / I~ .'sl h • Drill hol~ ~ | \-'~..-J I .,o,. \; / - - ~ • i ', I . ..-.' I I _.__----~. -~ P------- .,o. ,o,.- ,~ ! ~"~'-'I' I i ! ; ~--L:k ~-i _~' I l m , I k___ _[ I r-~' L-I" | ! _ ! i re_ ~ - - ' ~ / " , L / :~-v.~/L--- -- '~ , LL_ -,' , ~ ',,. ~-d Lr- ~l____ - -- -ok. I -~ .... -zth r'~-t I -- ~ ,__- ~- L-I - - r ~ - - I~ I I .~,, ,~. I ' - -~ I I",,~ t----- 0 100 200 Mi ~"~. _i, .3o, I l" \ ! / '--~. ' , ' , , ' ~E l l "~-. I 7 + 0 100 200 300 Km + -- -- + X )" / ÷ I I I I Fig. 17. Data points for Lower Jurassic II maps also showing lines of cross-section. See Table 5 for location names and references.
Page 1 and 2: Sedimentary Geology, 56 (1988) 3-12
Page 3 and 4: method of presentation because of t
Page 5 and 6: The presentation of each eolian-bea
Page 7 and 8: A A' MCNTANA WYOMING I BIGHORN POWD
Page 9 and 10: 46 ° 41 o 36' 31 ° 117 ° 112 °
Page 11: 46 ° ;I , 41 ° 117 ° 112 ° ~ '
Page 15: 117 ° 112 ° #-v~ ~ + / .~.,
Page 18 and 19: 46 ° 41 ° 36 ° 31 c 117 ! ° 112
Page 21 and 22: pp. 23-26 46 ° 41 o 36 ° 31 ° 11
Page 23: - 4' 117 ° 112 ° 107 ° 102 ° '
Page 26 and 27: 28 east into the Central Colorado t
Page 28 and 29: 30 Blakey (1986) documented the pre
Page 30 and 31: 32 A WYOMING : COLOR, DO A I SOUTH'
Page 34 and 35: , 117 ° 112 ° 107 ° 102 ° 40o~
Page 37 and 38: pp. 39-42 46 ° 41 ° 36 ~ 31 c -v_
Page 39: 117 ° 112 ° 107 ° 102 ° ' ¢ '
Page 42 and 43: G (B) SOURCES OF DATA FOR MIDDLE JU
Page 45 and 46: pp. 47"50 46 ° 41 `= 36 c -=-=.=.
Page 47: 117 ° 112 ° 107 ° 102 ° ! l I
Page 50 and 51: 52 C) A ID.~HO I WYOMING NORTHERN W
Page 52 and 53: 54 during the Jurassic Period (Pete
Page 54 and 55: 56 called the "Reservation facies".
Page 56 and 57: 58 A A' WYINE NEICO WIND RIVER LARA
Page 58 and 59: 60 F F' SS AT MESITA Recopture Mbr
Page 60 and 61: 62 member is unconformably overlain
Page 62 and 63: 64 B UTAH [ ARIZONA LAKE POWELL " I
Page 64 and 65: 66 misleading. The eolian beds are
Page 66 and 67: 117 ° 112 ° 107 ° 102 ° ' ¢ '
Page 69 and 70: pp. 71-74 46 ° 41 ° 36 ° 31'= 11
Page 71: ~o ~o o o o I I | I + O I I I -----
Page 74 and 75: 76 the logs so the contour lines ar
Page 76 and 77: 78 TABLE 1 Methodology used in cons
Page 78 and 79: 80 TABLE 2 (continued) Section Auth
Page 80 and 81: 82 TABLE 2 (continued) Section Auth
Page 82 and 83:
84 TABLE 2 (continued) Section Auth
Page 84 and 85:
Page 86 and 87:
88 TABLE 4 Data base for Wingate Sa
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
100 TABLE 6 (continued) Section Aut
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
Page 106 and 107:
Page 108 and 109:
Page 110 and 111:
Page 112 and 113:
Page 114 and 115:
Page 116 and 117:
118 Deposits of the Western Interio
Page 118 and 119:
120 Arizona, New Mexico, and Utah.
Page 120 and 121:
122 O'Sullivan, R.B., 1984. Stratig
Page 122 and 123:
124 Thaden, R.E., Thrites, A.F. and
show all

Synthesis of late Paleozoic and Mesozoic eolian deposits of the ...

Create successful ePaper yourself

Delete template?

Save as template?