Measured Sections (thickness in meters)
Measured Section 1: measured by J. Honey and P. Peláez-Campomanes, 1998
Top of section
14. Indurated caprock: CaCO3 horizon in orange-brown, silty, finegrained sandstone; rooted; burrowed; brecciated upper part; CaCO3 becomes more massive upwards 1.30
13. CaCO3, massive, indurated; shows mudcracks and slickensides; burrowed; base of CaCO3 horizon convoluted, and thickness of unit variable 0.61
12. Interbedded light brownish gray, clayey, very fine grained sandstone and sandy claystone; calcareous; burrows and possible roots present; forms cliff. Unit variable in thickness 0.91
11. Claystone, light brownish gray, slightly sandy, interbedded with thin (= 3 cm) layers of diffuse and nodular CaCO3; claystone layers up to 0.23 m thick. Upper 0.46 m of unit with less CaCO3 2.07
10. Sandstone, very fine to fine-grained, slightly silty, lacks pebbles; friable; grades below into underlying unit as part of fining-upwards package 1.13
9. Sand and gravel, yellowish-gray, crossbedded, with pebbles up to 7 cm long; unconsolidated. Pebbles decrease in size and sorting improves upwards. Blocks of cemented, crossbedded sand and gravel locally present. Rare bone fragments present 7.28
8. Sandstone, pinkish- to orange-gray, very fine grained, clayey. Lower half of unit with numerous CaCO3 nodules that form a prominent white, rubble slope; upper half of unit without nodules. Clay content increases in upper 0.61 m. Sharp top contact 3.14
7. Partly covered interval: sandstone, pinkish-gray, very fine grained, silty, massive; less silty in upper part; scattered CaCO3 nodules form rubble slope 2.23
6. CaCO3; light gray; contains root traces; forms ledge or rubble slope; up to 1.00 m thick laterally 0.40
5. Interbedded light greenish gray, very fine grained silty sandstone and sandy siltstone in lower half of unit, dominantly pinkish-gray silty sandstone in upper half of unit. Vertical root traces locally present. CaCO3 nodules up to 0.15 m across found about 0.8 m up from base. Sharp top contact. Bones are found nearby at this level, and locality MSU-1-98 (Wiens) is in this unit 1.60
4. CaCO3, white, locally with charophytes; forms prominent ledge. Wavy base 0.61
3. Sandstone, containing two cycles of reddish-brown, silty sandstone fining upwards from fine- to very fine grained. A thin layer of CaCO3 nodules is present 0.8 m up in unit and separates the two cycles. Lowest 0.8 m of unit locally shows low-angle crossbedding. Sharp top contact 1.91
2. Sandstone, orange-gray, friable, grading upwards into light-gray silty claystone 3.73
1. Sandstone, light orange brown, medium- to coarse-grained and containing some pebbles and cobbles; mostly unconsolidated except for some cemented, crossbedded ledges in upper part of unit; top 0.46 m of unit cemented and containing pebbles up to 2 cm long 1.68+
Base of exposure
Total measured section 28.60
Measured Section 2: measured between 6 and 18 m north of location of UK fossil locality 22, by J. Honey and P. Peláez-Campomanes, 1998.
Top of section
14. Unconsolidated gravelly sandstone; same as units 9 and 10 of measured section 1 5.79
13. Silty sandstone, light grayish brown; chippy weathering; contains CaCO3 mottling and scattered CaCO3 nodules. Sharp upper contact 2.53
12. CaCO3 zone, with nodules in reddish-brown, silty, very fine grained sandstone matrix; forms white layer on slope 1.34
11. Sandstone, greenish-gray, very fine grained, silty, massive, with CaCO3mottling 1.40
10. Claystone, reddish-brown, sandy 0.40
9. CaCO3 ledge, white 0.08
8. Light brownish gray, very fine grained silty sandstone and sandy siltstone; slightly blocky weathering; contains CaCO3 mottling and scattered nodules; massive. Forms gentle slope 0.76
7. CaCO3 layer, white, massive; irregular thickness 0.10
6. Sandstone, orange-brown, very fine to lower fine grained; massive with scattered CaCO3 nodules and stringers 1.68
5. CaCO3 zone, variable thickness, consisting of nodules in a light greenish gray to brownish-gray silty, very fine grained sandstone matrix; contains three CaCO3 horizons, the thickest one at the base of the unit 0.91
4. Silty sandstone, light greenish gray, very fine grained, slightly clayey; massive, with blocky weathering in places; contains scattered CaCO3 nodules; gradational lower contact with unit 3. Lower half of unit 4 included in Keefe Canyon layer C 0.46
3. Silty sandstone, dark brownish gray, very fine grained, slightly clayey and organic. Contains bone (= Keefe Canyon layer C) 0.15
2. Sandstone, light greenish gray, very fine grained with scattered medium grains; massive; hard. Contains bone (= Keefe Canyon layer B). Gradational top and base of unit 0.61
1. Sandstone, brownish-orange, upper fine to lower medium grained with scattered lower coarse grains; silty; massive in lower 0.61 m. Fines upward to very fine or fine-grained, greenish-gray sandstone, and in top 0.10 m is a greenish-gray sandy claystone. Keefe Canyon layer A is from 0.61 m to 0.98 m above base of section 1.07
Base of exposure
Total measured section 17.28
Measured Section 3: measured by J. Honey and D. Porter, 1999.
Top of section
11. Sand and gravel; not measured
10. Covered interval 9.60
9. Indurated CaC03 caprock; abundant root holes and vertical tubes 1-10 mm across; undulating base 0.45
8. Mudstone, light brownish gray, containing very fine grains of sand; carbonaceous; calcareous 0.13
7. Silty mudstone, light medium gray, with scattered very fine grains of sand; extremely calcareous, hard; relict root traces 0.33
6. Sandstone, lower very fine grained, silty. Upper half of unit shows clay content increasing upward. Top 0.23 m contains carbonaceous material and clay films, and shows orange mottling along root traces 1.13
5. Claystone, calcareous, with carbonate nodules up to at least 0.08 m across scattered throughout unit. Bottom 0.17 m contains more carbonate nodules. Upper 0.36 m possibly pedogenically modified 0.52
4. Claystone, with orange mottling. Gradational top contact 0.30
3. Claystone, olive-green, slightly sandy, with scattered brownish-black carbonaceous streaks; massive. Contains some probable burrows. Contains bone in basal 0.08 m of unit. Grades into overlying unit 0.16
2. Claystone, pale brown, silty, slightly sandy; massive. Sharp top contact 0.47
1. Sandstone, light orange gray, very fine grained with scattered coarse grains. Contains burrows filled with fine- to medium-grained sandy clay and soft masses of carbonate. Grades into overlying unit through a contact of one or two cm 0.23+
Start near base of exposure
Total measured section 13.32
Measured Section 4: measured by J. Honey and D. Porter, 1999.
Top of section
7. Sand and gravel; same as units 9 and 10 of measured section 1 4.88 Covered interval 3.02
6. Sandy mudstone, reddish-brown, with disseminated CaCO3 nodules and discontinuous ledges; probable vertisol 3.00
5. Sand, light reddish brown, silty, massive; forms cliff 2.06
4. Interbedded sandy CaCO3 and pale olive gray, silty sand, locally calcareous; fossil root traces present. This unit correlates with lower part of unit 9 of measured section 5 0.53
3. Sandstone, reddish-brown, silty, massive; contains zone of carbonate nodules about 0.15 m thick starting 0.15 m above base of unit. Forms vertical cliff 1.65
2. Siltstone, reddish-brown, sandy; contains vertical cracks; locally truncated by sands that may be related to the overlying cliff-forming sandstone 0.79
1. Sandstone, very fine grained, silty; contains thin, discontinuous CaCO3 interbeds up to 3 cm, and scattered root traces. Top of unit defined by a discontinuous CaCO3 ledge. Beds making up this unit converge from north to south over a distance of 18.3 m; appears to be of fluvial origin ~1.67
Total measured section 17.6
Measured Section 5: measured by J. Honey and D. Porter, 1999.
Top of section
11. Sandstone, pale orange brown, very fine grained, silty, contains scattered CaCO3 layers and nodules up to 0.06 m in length; probable vertisol 1.98
10. Siltstone, light-gray, sandy, with disseminated CaCO3 nodules and scattered minute root traces; weakly ledge-forming at top. Grades into overlying unit 0.41
9. Calcareous mudstone, very light gray, composed mainly of fusing CaCO3 nodules. Lower 0.41 m forms resistant CaCO3 ledge; top 0.79 m shows upwards decrease in nodules 1.19
8. Sandstone, pale orange brown, very fine grained, quartzitic, slightly silty; contains scattered CaCO3 nodules in local lenses; traces of low-angle crossbedding; CaCO3 rip-up clasts in basal 15 cm. Undulating lower contact with up to 0.15 m relief. Thickness measurement taken on edge of channel; in deepest part of channel, unit 10 is 3.05 m thick 0.76
7. Sandstone; orange-brown, very fine grained; traces of cross-laminae; scattered root traces; contains some mollusks 0.51
6. Sandstone, very fine grained, silty at top; concentrations of CaCO3 rip-up clasts at base of unit; massive. Gradational top contact 1.50
5. Sandstone, pale orange brown, very fine grained, silty, faint traces of bedding; discontinuous 0.05 m CaCO3 layer about 0.41 m above base; thin clay stringers and scattered carbonaceous material in upper part of unit. Sharp top contact 1.32
4. Sandstone, very fine grained, silty; contains some clay laminae and disseminated CaCO3. Sharp top contact 0.25
3. CaCO3 layer, white, formed in silty clay; contains minor root traces. 0.03 m thick clay layer present 0.18 m up from base of unit 0.28
2. Silty claystone, light-brown in lower 0.38 m, olive-green in upper 0.27 m; contains scattered fine- to medium-grained sand; some small burrows; upper 0.27 m with some carbonaceous stringers and increasingly calcareous. Gradational top contact 0.65
1. Sandstone, light-brown, very fine grained, silty, clayey 0.30+
Total measured section 9.15
Measured Section 6: measured by J. Honey and P. Peláez-Campomanes, 1998.
Top of section
13. Sandstone, orange-brown, silty; calcareous. Correlates with probable vertisol (unit 11) in measured section 5 0.79
12. CaCO3 zone formed in silty, fine- to medium-grained sandstone; forms prominent white layer on outcrop 0.82
11. Sandstone, light brownish gray, mainly fine-grained, silty 0.49
10. CaCO3 zone, white, massive 0.89
9. Sandstone, orange-brown; fine- to medium-grained with lenses of CaCO3 rip-up clasts in basal 0.13 m; small scale crossbedding present; upper part of unit very fine grained and silty. Unit measured near edge of channel; in deepest part of channel, unit is about 1.83 m thick and shows superposed sets of crossbedding 0.61
8. CaCO3, white, massive. Eroded in center of outcrop by unit 9 0.18
7. Sandstone, light orange brown, very fine grained, silty, with a few green clay layers up to 2.5 cm thick; ripple laminated; massive in top 0.46 m. Locally, unit is coarser-grained at base. Sharp, undulating top contact 0.99
6. Sandstone, light grayish green, very fine grained, silty, massive; top 0.13 m of unit calcareous. Sharp top contact with up to 0.30 m relief. Unit thickens to 1.07 m laterally. Contains mammal fossils (locality MSU-10-98) 0.79
5. Unit consisting of 0.30 m thick basal zone of CaCO3 nodule formation, with nodules up to 3 cm across. Upper 0.46 m of unit consists of light greenish gray, very fine grained, silty sandstone containing only rare CaCO3 nodules; top several cm with scattered coarse grains of sand. Sharp top contact 0.76
4. Unit consisting of 0.18 m thick basal zone of CaCO3 nodule formation in a light olive gray, very fine grained, silty sandstone and sandy siltstone. Upper 0.61 m of unit shows columnar structure with CaCO3 mottling, but without distinct CaCO3 horizons 0.81
3. Sandstone, light orange brown grading up to light olive gray; very fine grained, slightly silty, massive; contains scattered CaCO3 nodules forming discontinuous horizon in basal 0.30 m of unit. Top 0.25 m of unit with scattered CaCO3 nodules and columnar structure. Mammal fossils taken from middle of unit 0.86
2. Sandstone, brownish-gray, very fine grained, silty, carbonaceous, containing rare, scattered mollusks. Grades up to light olive gray sandstone with abundant mollusks and scattered CaCO3 nodules and mottling. Probably is part of Hibbard and Riggs's (1949) gastropod-bearing unit 3 in their Keefe Canyon measured section 0.30
1. Sandstone, light yellowish to light olive gray, very fine to finegrained, silty, with scattered mollusks; 1 cm thick CaCO3 layer at top. Probably part of Hibbard and Riggs's (1949) unit 3 0.30+
Total measured section 8.59
Measured Section 7: measured by J. Honey and P. Peláez-Campomanes, 1998.
Top of section
14. CaCO3 zone, containing nodules and laminae in a clayey matrix; cementation increases upwards. Forms rubble bench 1.07
13. Interbedded clayey, very fine grained sandstone and siltstone, light olive gray to light medium gray; contains 5.1 cm thick CaCO3 cemented zone 0.46 m from top of unit 1.52
12. Interbedded light olive gray sandy claystone and clayey sandstone 1.37
11. Interbedded fine-grained, silty sandstone and sandy siltstone in lower 2/3 of unit, pinkish-brown to light medium gray; grades up to medium-to light brownish gray, sandy siltstone in top 1/3 of unit. Top 0.25 m of unit is a CaCO3 zone consisting of partially fused nodules 3.56
10. Claystone, moderate yellowish brown 0.94
9. CaCO3 layer; forms thin bench 0.10
8. Sandstone, pinkish-brown, fine-grained, silty. About 0.76 m above base is a 5 cm thick CaCO3 mottled zone 1.68
7. Muddy sandstone, pinkish-brown, medium- to coarse-grained, with CaCO3 mottling; contains scattered pebbles; 2.5 cm thick CaCO3 layer at top of unit 0.38
6. Claystone, light olive gray with CaCO3 mottling. Sharp top contact 0.23
5. Sandstone, yellowish-gray, very fine to fine-grained, silty; contains scattered carbonaceous fragments and CaCO3 mottling. Gradational top contact 0.46
4. Sandstone, medium- to coarse-grained with a few thin silty and clayey laminae; crossbedding present, outlined by carbonaceous material. Locally forms cemented ledge 0.13
3. Sandstone, yellowish-orange, medium- to coarse-grained with scattered pebbles and cobbles. Fines up to fine- to lower medium grained with only a few pebbles. Gradational top contact 1.42
2. Sandstone, reddish-brown, fine-grained, clayey and silty; scattered CaCO3 mottling. Sharp top contact 0.76
1. Sandstone, yellowish-gray, medium- to coarse-grained; contains pebbles of white quartz, gray chert, and red granitic rock in lower part of unit. Fines upward to fine- to medium-grained. Top of 20 cm thick, yellow cemented ledge containing scattered pebbles, is present 0.53 m down from top of unit. Top contact gradational; base not exposed 5.89+
Total measured section 19.51
Measured Section 8 (MSU-16-00): measured by J. Honey, P. Peláez-Campomanes, and R. Martin, 2001.
Top of section
14. Sand and gravel, unconsolidated; mostly covered 7.16
13. Sandstone, light-brown, very fine to fine-grained, slightly silty with CaCO3 mottling; strongly CaCO3 cemented in top 0.74 m 1.52
12. Partly covered interval consisting of very fine grained, silty sandstone; contains CaCO3 nodules that decrease in abundance upwards. Sharp top contact 3.99
11. Partly covered interval consisting of light-brown, very fine grained sandy siltstone; contains abundant CaCO3 nodules and rubble that forms white band across hillside. Gradational top contact 1.68
10. Mostly covered interval apparently consisting of pinkish-gray siltstone 3.38
9. CaCO3 interval; upper 0.15 m more massive 0.84
8. Siltstone, pinkish-orange, sandy, with scattered thin layers and nodules of CaCO3 1.68
7. CaCO3 and siltstone; forms ledge 0.23
6. Siltstone, sandy 0.36
5. Siltstone; contains scattered CaCO3nodules 0.15
4. Siltstone, sandy, massive 0.30
3. CaCO3, forms ledge 0.13
2. Sandstone, pinkish-gray, very fine grained, silty, massive. Forms vertical wall. Contains mammal fossils (locality MSU-16-00) 1.40
1. Sandstone, light-brown, silty; contains CaCO3 nodules in scattered thin layers that are concentrated in top 0.46 m of unit. Gradational top contact 0.61+
Base of exposure
Total measured section 23.43
Measured Section 9: measured by J. Honey and P. Peláez-Campomanes, 2001.
Top of section
6. Modern soil 0.91
5. Siltstone, reddish-brown, sandy, with abundant CaCO3 nodules and stringers 2.29
4. Interbedded light olive gray siltstone and silty claystone 0.46
3. CaCO3 ledge 0.10
2. Siltstone, light-gray, sandy 0.30
1. CaCO3 0.43
Total measured section 4.49
Measured Section 10 (mollusk locality 4b of Taylor (1960; 1966)): measured by J. Honey and P. Peláez-Campomanes, 2001.
Top of section
6. Sandstone, grayish-orange, fine- to medium-grained, silty; contains claystone rip-up clasts in lowest several cm 1.98
5. Claystone; basal 0.15 m is light olive gray, slightly silty with carbonaceous streaks, and with abundant mollusks (locality4b). Overlain by olive-brown to light-gray claystone. Sharp top contact 0.91
4. Sandstone, pale yellowish brown, very fine to fine-grained with scattered medium grains; silty. In top several cm, unit contains interbedded silty sandstone and siltstone with mollusks 0.46
3. Covered interval, apparently consisting of dark yellowish orange silty sandstone and siltstone 1.78
2. CaCO3, white, laminated, with wavy base and top 0.61
1. Sandstone, dark yellowish orange, fine- to medium-grained, with rare pebbles up to 3 mm; silty; contains localized CaCO3 mottling and nodules; massive 2.62+
Base of exposure
Total measured section 8.35
Measured section 11: about 50 m upstream from Hibbard's Fox Canyon locality. Measured by J. Honey and P. Peláez-Campomanes, 2001.
Top of section
12. Sand and gravel; not measured
11. Covered interval, consisting in part of reddish-brown, fine- to medium grained, silty sandstone; contains some root traces; abundant caliche nodules in the lowest 5.0 m 7.00
10. Mostly covered interval consisting of pale reddish brown to lightbrown, fine-grained, slightly silty sandstone with some CaCO3 mottling. Increase in silt, CaCO3 mottling, and CaCO3 nodules higher in unit. At top of unit is a 0.15 m thick CaCO3 layer that forms bench 2.59
9. Sandstone, fine- to medium-grained, silty, with abundant CaCO3 nodules and mottling in upper part of unit below modern soil; massive. Top of unit forms bench with nodules. Unit forms white band on hillside 2.59
8. Sandstone, fine- to medium-grained; very silty, with some interbedded siltstone and minor clay in lowest 0.61 m; becomes less silty upwards and contains rare, wavy, thin CaCO3 layers. Gradational upper contact 2.29
7. Claystone, medium light gray to medium-gray, becoming brownish and olive colored higher up; shows some CaCO3 mottling. Sharp top contact 1.12
6. Sandstone, very light gray, very fine grained, slightly silty, massive 0.38
5. Claystone, dusky yellow to light olive gray; slightly carbonaceous 0.18
4. CaCO3; forms thin ledge 0.09
3. Sandstone, pale yellowish brown, very fine to fine-grained with scattered medium grains, silty; becomes less silty and shows lamination in upper part of unit 0.69
2. Claystone, moderate yellowish brown grading up to dusky yellow; slightly sandy 0.43
1. Sandstone, dark yellowish orange, fine- to medium-grained with some coarse grains of quartz and chert; generally friable and massive, but locally is cemented and shows some crossbedding; contains mammal bones at Hibbard's Fox Canyon locality. Base not exposed 0.91+
Base of exposure
Total measured section 14.8
Measured Section 12 (Fractal Canyon): measured by J. Honey, P. Peláez-Campomanes, and R. Martin, 2001.
Top of section
7. Sand and gravel; not measured
6. Interbedded very fine grained silty sandstone and sandy siltstone; CaCO3 nodules disseminated throughout, with greater concentration of nodules 2.99 m up from base of unit 5.33
5. Interbedded reddish-brown silty sandstone and CaCO3 layers; wavy; possible vertisol 1.22
4. Sandstone, silty, reddish-brown; contains scattered CaCO3 nodules. Highly irregular upper contact 1.28
3. Claystone, silty; light-gray with abundant CaCO3 nodules in lower 0.40 m, overlain by olive-gray to reddish-brown silty claystone; 0.12 m CaCO3 ledge at top 0.94
2. Claystone, light-gray, silty. Gradational top contact 0.30
1. Covered interval 0.91
Section begins on top of mollusk-bearing CaCO3 layer in bottom of wash
Total measured section 9.98
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