Sample

number

BHV-T03

BHV-T05

BHV-T06

BHV-T08

BHV-T07

BHV-T09

BHV-T04

BHV-T02

BHV-T01

PV-T01

Locationa

x, y (m)

9.95, 2.15

9.30, 1.90

11.60, 2.65

10.43, 1.85

11.15, 1.85

11.50, 1.10

8.70, 1.75

11.20, 0.95

22.60, 4.90

0369666 E.

4648189 N.

Unit 

number

7e

7c

6b

6a

5b

5a

4

4

2a

Barrier

bar sand

Datingb

method

TL-tb

IRSL

TL-tb

IRSL

TL-tb

IRSL

TL-tb

IRSL

TL-tb

IRSL

TL-tb

IRSL

TL-tb

IRSL

TL-tb

IRSL

TL-tb

IRSL

OSL-L

OSL-E

Temperaturec

data (°C)

124

124/64 hrs

124

124/64 hrs

124

124/64 hrs

124

124/64 hrs

124

124/64 hrs

124

124/64 hrs

124

124/64 hrs

124

124/64 hrs

124

124/54 hrs

220/10 min.

220/10 min.

Equivalentd

dose (Grays)

16.75 ± 1.36 

15.47 ± 0.92 

16.51 ± 1.39 

10.68 ± 0.29 

9.50 ± 0.79 

15.29 ± 0.46 

24.03 ± 1.01 

22.99 ± 0.43 

23.09 ± 1.84 

24.09 ± 0.56 

44.56 ± 1.08 

42.64 ± 0.47 

25.28 ± 2.07 

24.39 ± 0.73 

18.54 ± 1.36 

18.76 ± 0.49 

56.41 ± 1.27 

52.64 ± 0.74 

76.4 ± 14.1 

76.4 ± 14.1 

Dose Ratee

 (Grays/ky)

4.61 ± 0.06

4.38 ± 0.06

4.53 ± 0.08

4.30 ± 0.08

4.97 ± 0.08

4.72 ± 0.08

4.89 ± 0.08

4.65 ± 0.07

5.01 ± 0.07

4.76 ± 0.07

4.40 ± 0.06

4.18 ± 0.06

4.30 ± 0.06

4.09 ± 0.06

4.64 ± 0.08

4.41 ± 0.08

4.89 ± 0.11

4.64 ± 0.11

3.96 ± 0.07

3.96 ± 0.07

Fieldf

moisture (pct.)

15

15

20

20

19

19

13

13

13

13

19

19

19

19

16

16

13

13

 1 

1 

Fadingh

(pct./decade)

1 

5 

5 

5 

5 

 5* 

 5* 

 5* 

 5* 

2 

2 

1 

1 

17 

17 

3 

3 

Na 

Na 

Na 

TL, IRSL, org

 OSL age (yr)

3,640 ± 600 

3,530 ± 430 

3,650 ± 630 

2,480 ± 160 

>1,910 ± 320 

3,240 ± 220 

4,910 ± 440 

4,940 ± 240 

4,610 ± 740 

5,060 ± 270 

10,140 ± 570 

10,200 ± 400 

5,880 ± 970 

5,960 ± 400 

3,990 ± 600 

4,250 ± 270 

11,540 ± 740 

11,340 ± 610 

19,310 ± 7150 

16,390 ± 5038 

Fading-correctedi 

age (yr)

3,770 ± 620 

3,650 ± 450 

4,790 ± 830 

3,220 ± 210 

>2,290 ± 380 

3,930 ± 270 

6,020 ± 540 

6,060 ± 300 

5,640 ± 910 

6,210 ± 330 

11,080 ± 620 

11,150 ± 440 

6,090 ± 1,005 

6,180 ± 420 

16,590 ± 2,540 

18,190 ± 1,280 

13,250 ± 850 

13,020 ± 700 

Na

Na

Preferred agej

 estimate (yr)

3,690 ± 360 

Na

4,790 ± 830 

Na

 Na

3,930 ± 270 

6,050 ± 260 

Na

6,140 ± 310 

Na

11,130 ± 360 

Na

--

Na

17,870 ± 1,140 

Na

--

Na

17,360 ± 4,120 

Na

Comments

Weighted mean of fading-corrected TL and IRSL ages; calibrated radiocarbon ages from same horizon yield similar age.

None.

Overlying calibrated radiocarbon ages yield similar age.

IRSL age is weighted mean of two analyses; overlying radiocarbon ages indicate age is too young.

None.

Overlying radiocarbon ages indicate age is too young by several hundred years.

Weighted mean of fading-corrected TL and IRSL ages; fading estimated from sample BHV-T06.

None.

Weighted mean of fading-corrected TL and IRSL ages; fading estimated from sample BHV-T06.

None.

Weighted mean of fading-corrected TL and IRSL ages.

IRSL age is weighted mean of two IRSL analyses.

No preferred age; pluvial lake history suggests all ages too young; sample contaminated with infiltrated silt(?).

None.

Weighted mean of fading-corrected TL and IRSL ages.

None.

No preferred age; regional pluvial lake history and overlying sample BHV-T02 suggest all ages too young.

None.

Weighted mean of linear and exponential fit OSL ages.

None.

a

All BHV sample locations from gridded south wall of Bog Hot Valley trench; PV sample is from 95 cm depth in soil pit in barrier bar in Pueblo Valley, 23 km northeast of trench site; PV location in UTM coordinates (NAD 84) from handheld GPS. b

TL-tb, thermoluminescence—total bleach; IRSL, infrared-stimulated luminescence; OSL-L, blue-light optically-stimulated luminescence, single aliquot regeneration, linear fit; OSL-E, blue-light optically-stimulated luminescence, single aliquot regeneration, exponential fit. c

Values for TL are plateau temperatures; values for IRSL and OSL are preheat temperatures.

d

Uncertainties are ± 1 sigma.

e

Trench dose rates from in-situ measurements with Exploranium GR-256 gamma ray spectrometer at field moisture, then recalculated to 30 percent moisture (except BHV-T02 and BHV-T08, which use 20 percent moisture); sample PV-T01 dose rate measured by laboratory analysis (high-resolution gamma spectrometry) of bulk sediment sample 

at field moisture, recalculated to 20 percent moisture; uncertainties are ± 1 sigma. f

Moisture contents of sealed field samples measured by weight in the laboratory.

g

Uncertainties are ± 2 sigma.

h

Anomalous-fading factor (Huntley and Lamothe, 2001) calculated from laboratory fading tests; values marked with * are estimated from nearby samples; Na, not applicable to OSL sample. i

Corrected ages; anomalous-fading factor in previous column applied to each age (Huntley and Lamothe, 2001); Na, not applicable to OSL sample. j

Preferred ages; mean ages are error weighted with ± 2 sigma uncertainties; --, not calculated, ages likely in error; Na, not applicable.

Table 2. Luminescence data from the Bog Hot Valley and Pueblo Valley sites.

Profilea

number

BHV-1

BHV-2

BHV-3

BHV-4

BHV-5

BHV-6

BHV-7

BHV-8

BHV-9

BHV-10

BHV-11

BHV-12

BHV-13

Scarpb

 

height (m)

4.3

3.8

4.5

4.1

4.2

3.3

2.5

3.7

2.2

2.8

2.4

3.3

5.1

Surfaceb

offset (m)

4.3

3.8

3.5

4.0

4.2

2.9

2.2

3.1

1.9

2.5

2.0

2.6

4.6

Max. slope 

angle (°)

15.5

16.6

17.2

18.3

15.5

17.9

15.0

22.5

17.0

17.0

13.1

14.1

16.0

Lower slope

angle (°)

0.0

0.0

4.0

0.5

0.0

2.0

1.3

4.2

2.4

1.5

3.5

3.0

2.0

Upper slope

angle (°)

0.0

0.0

3.7

0.7

0.0

2.0

1.6

3.7

2.4

1.7

1.3

3.1

1.3

Avg. slope

angle (°)

0.0

0.0

3.8

0.6

0.0

2.0

1.4

3.9

2.4

1.6

2.4

3.1

1.6

Dip slipc

(60°, m)

5.0

4.4

4.2

4.6

4.8

3.4

2.6

3.7

2.2

3.0

2.3

3.1

5.4

Dip slipc

 (77°, m)

4.5

3.9

3.6

4.1

4.3

3.0

2.3

3.2

1.9

2.6

2.0

2.7

4.8

Comments

Trench site profile in lacustrine silt, sand, and gravel on valley floor.

 Profile in lacustrine silt, sand, and gravel on valley floor.

 Profile in lacustrine silt, sand, and gravel on valley floor.

 Profile in lacustrine silt, sand, and gravel on valley floor.

 Profile in lacustrine sand on valley floor.

 Profile in lacustrine sand on valley floor.

 Profile in sandy alluvium on valley floor.

 Profile in cobbly alluvium at Pine Forest Range mountain front.

 Triggered(?) scarp on east side of valley in lacustrine pebble gravel.

 Profile in cobbly alluvium on valley floor.

 Profile in cobbly alluvium on valley floor.

 Profile in sandy pebble-cobble alluvium on valley floor.

 Collapsed trench site profile in cobbly alluvium on valley floor.

a

Locations marked on figure 3.

b

Scarp height and surface offset (vertical separation) as defined by Bucknam and Anderson (1979).

c

Calculated values using equations of Caskey (1995) based on surface offset (vertical separation), average slope of the ground surface, and fault dip estimates based on values of typical Basin and Range 

faults (60°) and dip measured in Bog Hot Valley trench (77°).

Table 4. Fault scarp profile and slip data from Bog Hot Valley.

Colord

moist

10YR 4/4

10YR 4/5

10YR 4/3

10YR 4/4

2.5Y 4/3

10YR 4/3

10YR 4.5/4

10YR 4.5/4

10YR 4.5/4

10YR 3/3

10YR 3/3

10YR 4/1

10YR 5/4

10YR 4.5/4

10YR 5.5/4

10YR 4.5/4

10YR 5.5/4

10YR 4/1

10YR 4/3

10YR 5/2

10YR 4/3

10YR 4/3

10YR 5/4

10YR 4/3

10YR 5/4

Parentb

 material

4

4

4

4

4

4, 3, 2

7e

7e

7c

4

4

3f

sp4

sp4

sp4

sp4

sp4

sp3

loess

loess

loess

sand, gravel

sand, gravel

sand, gravel

sand, gravel

Depth

top (cm)

0 

8 

18 

33 

43 

56 

0 

15 

49 

61 

95 

135 

0 

18 

42 

54 

66 

84 

0 

8 

14 

24 

31 

40 

55 

Depth

base (cm)

8 

18 

33 

43 

56 

180+ 

15 

49 

61 

95 

135 

200+ 

18 

42 

54 

66 

84 

135+ 

8 

14 

24 

31 

40 

55 

120+ 

Lowerc

boundary

 cs

 cw

 gw

 cw

 aw

 ne

 cs

 gs

 cs

 gw

 cw

 ne

 cs

 cs

 cw

 gw

 cw

 ne

 cs

 cs

 cs

 cs

 cs

 cs

 ne

Colord

dry

10YR 6/3

10YR 6/3

10YR 7/3

10YR 6/3

2.5Y 6/3

10YR 6.5/2

10YR 6.5/3

10YR 6/3

10YR 6.5/2

10YR 2/2

10YR 7/3

10YR 6/1

10YR 7/3

10YR 6.5/3

10YR 6/4

10YR 6.5/3

10YR 6.5/3

10YR 5/2

10YR 6/2

10YR 7/2

10YR 6/2

10YR 5/2

10YR 8/1

10YR 5/3

10YR 6/3

Texturee

 SiCL

 LS, SL

 L

 SL

 SL

 LS

 SL

 SiCL

 SiC

 SiL

 SiL

 S

 SiCL

 SiCL

 SiCL

 CL

 SiL

 S

 SL

 L

 SCL

 SCL

 LS

 S

 S

Horizona

A1

2A

2Btk

2Bky

2By

2C

A1

A2

2C

3Bkyb

3Bkb

4C

 A1

AB

2Btk

2Bky

2By

3C

A1

AB

Bt

2Bt

2Bk1

2Bk2

2C

Gravel

pct.

0 

<10 

<10 

<10 

<10 

<10 

25 

<10 

0 

<10 

0 

75 

0 

<10 

<10 

10 

10 

50–75 

0 

0 

<5 

75 

75 

50–75 

50–75 

Structuref

 2c, abk

 1f, p

 2m, sbk

 2m, sbk

 2m, sbk

 1m, sbk

 1m, sbk

 1f, sbk

 m

 2m, abk

 2m, sbk

 m

 2m, abk

 1f, p

 1f, sbk

 1f, sbk

 1f, sbk

 m

 1f, gr

 1m, gr

 1vf, sbk

 1vf, sbk

 m

 m

 m

Dryg

consistence

 sh

 sh

 h

 sh

 h

 sh

 so

 h

 sh

 sh

 sh

 sh

 so

 h

 h

 h

 sh

 sh

 so

 sh

 sh

 sh

 h

 lo

 lo

Wetg

consistence

 ss, ps

 so–ss, po

 s, ps

 ss, ps

 ss, ps

 so, po

 so, po

 ss, ps

 s, ps

 ss, po

 so, po

 so, po

 s, ps

 s, p

 s, ps

 s, ps

 ss, ps

 so, po

 so, po

 ss, ps

 s, p

 s, p

 so, po

 so, po

 so, po

Clayh

films

0

0

2d, pf

0

0

0

0

0

0

nd

0

0

0

0

nd

0

0

0

0

0

1f, pf

1f, pf, po

0

0

0

Commentsi

Loess in pans.

Abundant fine rootlets.

Stage I carbonate in veinlets.

Stage I carbonate and gypsum in veinlets.

Abundant gypsum.

Lacustrine sand, sparse carbonate on bedding (nonpedogenic).

None.

None.

None.

Stage I carbonate.

Stage II(?) carbonate.

Stage I carbonate on bedding (nonpedogenic).

Spoil(?).

Stage I(?) carbonate.

Stage II carbonate.

Stage II carbonate and gypsum.

None.

None.

Bioturbation (rodents?) common.

Bioturbation (rodents?) common.

Some discontinuous reddish groundwater oxidation in upper part

 of sand and gravel.

Stage I+ carbonate; coatings on all grains.

Stage I- carbonate; discontinuous coatings on some pebbles.

Sparse carbonate on bedding (nonpedogenic).

a

Horizon nomenclature from Soil Survey Staff (1999) and Birkeland (1999).

b

Parent material: BHV trench and soil pit profiles—entries are log units; Pueblo Valley profile: loess—post-lacustrine windblown silt; sand, gravel—well stratified pluvial Lake Alvord barrier-bar sand and gravel. c

Lower boundary: Distinctness: a, abrupt; c, clear; g, gradual; Topography: s, smooth; w, wavy; ne, not exposed.

d

Color nomenclature from Munsell Color (1994).

e

Texture classes: CL, clay loam; L, loam; LS, loamy sand; SCL, sandy clay loam; SL, sandy loam; S, sand; SiL, silt loam; SiC, silty clay; SiCL, silty clay loam. f 

Structure: Grade: m, massive; 1, weak; 2, moderate; Size class: vf, very fine; f, fine; m, medium; c, coarse; Type: abk, angular blocky; sbk, subangular blocky; gr, granular; p, prismatic.

g

Consistence: Dry: lo, loose; so, soft; sh, slightly hard; h, hard; Wet: so, nonsticky; ss, slightly sticky; s, sticky; po; nonplastic; ps, slightly plastic; p, plastic. h

Clay films: Amount: 0, none; 1, few; 2, common; Distinctness: d, distinct; f, faint; Location: pf, on ped faces; po, in pores; nd, not determined. i

Carbonate nomenclature from Birkeland (1999).

Table 1. Soils data from Bog Hot Valley and Peublo Valley sites.

Profile S1-BHV trench footwall, south wall, 29.8 m horizontal datum

Profile S2-BHV trench hanging wall, south wall, 4.5 m horizontal datum

Profile S3–BHV soil pit, south wall, -21.8 m horizontal datum

Profile S4–Pueblo Valley soil pit in barrier bar, elevation ~4,250 ft (1,295 m)

Table 3. Unit descriptions from Bog Hot Valley trench site.

Unit

number

1a

1b

1c

1d

1e

1f

1g

1h

2a

2a

2b

2b

3a

3b

3b

3b

3b

3b

3b

K

K

3c

K

3d

K

3e

3e

3f

3f

3f

3f

3f

3g

3g

3g

4

4

4

4

4

4

K

K

K

4blk

5a

5b

5blk

5blk

5c

5d

6a

6a

6b

7a

7b

7c

7c

7d

7e

7e

7e

7e

8

sp3

sp3

sp3

sp4

Locationa

x, y (m)

12.60, 0.75

13.50, 1.75

13.00, 1.45

13.00, 1.80

13.30, 2.40

17.00, 4.00

13.50, 3.10

14.00, 3.60

20.00, 4.70

15.50, 4.50

25.00, 5.10

27.00, 5.30

30.00, 5.45

30.80, 6.00

31.00, 5.90

30.90, 5.50

30.50, 5.60

30.40, 5.70

26.20, 6.00

29.60, 5.80

31.40, 6.00

27.40, 6.00

27.20, 5.65

21.50, 5.75

28.40, 6.00

6.30, 0.80

6.40, 0.70

6.30, 0.95

6.40, 1.00

5.70, 1.30

5.90, 1.45

8.00, 0.60

6.70, 1.45

6.70, 1.50

8.00, 0.90

29.00, 6.25

5.00, 2.00

5.00, 2.30

9.00, 1.20

8.20, 1.00

11.25, 0.70

3.10, 1.90

5.25, 1.80

6.55, 1.90

11.00, 1.40

12.25, 1.70

10.75, 1.70

11.45, 1.90

11.85, 2.05

10.60, 1.25

10.70, 0.80

12.00, 2.00

10.60, 1.80

12.50, 2.60

12.75, 2.80

13.00, 3.10

8.00, 2.20

8.50, 1.95

10.50, 2.70

11.60, 3.00

8.50, 2.70

9.70, 2.70

10.80, 3.30

11.00, 3.60

-19.50, 2.20

-22.50, 1.90

-21.00, 1.50

-22.00, 2.40

Matrixb

grain size

Silty sand

Cse-v cse sand

Silty sand

Silty sand

Silty sand

Cse-v cse sand

Silt

Silty sand

Silt

Silt

V cse sand

V fn sand

Med sand

Cse sand

Cse sand

Med sand

Med sand

V fn sand

Med sand

Med sand

Fn sand

V cse sand

Med sand

Cse sand

Med sand

Med sand

Med sand

Cse sand

Med sand

Med sand

Cse sand

Cse sand

Med sand

Cse sand

V fn sand

V fn sand

Silt

Silt

Silt

Silt

Silt

Med sand

Cse sand

Cse sand

Silt

Cse sand

Silt

Fn sand

Fn sand

Silt

Med sand

V cse sand

Silt

Silt

Cse sand

V cse sand

Silt

Silt

Fn-cse sand

Sandy silt

Fn sand

 Sandy silt

Sandy silt

Sandy silt

V cse sand

Med sand

V cse sand

Silt

Gravel

pct.

<3 

>50 

<3 

<3 

>50 

>50 

<1 

25 

<1 

<1 

40 

0 

<10 

30 

25 

<10 

<10 

0 

<10 

<10 

<10 

30 

0 

40 

<10 

50 

<10 

10 

0 

<10 

10 

10 

<10 

<10 

0 

0 

0 

0 

0 

0 

0 

10 

20 

<10 

0 

30 

<10 

0 

<10 

0 

0 

70 

0 

<10 

25 

80 

0 

0 

<10 

25 

15 

<10 

<10 

<10 

30 

<10 

80 

10 

Largestb

clast (mm)

<5 

50 

6 

3 

40 

100 

1 

60 

3 

3 

80 

Na 

 20 

20 

20 

12 

10 

Na 

15 

50 

5 

50 

Na 

50 

10 

60 

10 

30 

Na 

5 

20 

20 

25 

15 

Na 

Na 

Na 

Na 

Na 

Na 

Na 

10 

10 

20 

Na 

20 

10 

Na 

20 

Na 

Na 

100 

Na 

20 

15 

110 

Na 

Na 

 15 

35 

5 

6 

10 

10 

300 

10 

450 

12 

Sorting

Well

Poor

Well

Well

Poor

Poor

Well

Well

Well

Well

Poor

Well

Well

Moderate

Well

Moderate

Moderate

Very well

Moderate

Moderate

Well

Poor

Well

Poor

Moderate

Poor

Moderate

Moderate

Well

Well

Moderate

Moderate

Well

Well

Well

Very well

Very well

Very well

Very well

Well

Very well

Moderate

Moderate

Moderate

Well

Moderate

Moderate

Moderate

Moderate

Well

Well

Poor

Well

Moderate

Moderate

Poor

Well

Well

Well

Poor

Poor

Well

Well

Moderate

Poor

Well

Poor

Poor

Dryc

color

10YR 6.5/3

10YR 6.5/2

10YR 6.5/3

10YR 6.5/3

10YR 6.5/2

10YR 6.5/2

10YR 6.5/2

10YR 6.5/3

2.5Y 7/3

2.5Y 7/3

10YR 7/1

10YR 8/2

10YR 8/2

10YR 7/1

2.5Y 7/4

10YR 5/3

10YR 5/3

10YR 8/1

10YR 7/1

2.5Y 7/2

2.5Y 7/2

10YR 6/1

2.5Y 8/2

10YR 8/2

10YR 6/4

10YR 7/1

10YR 7/1

10YR 6/1

10YR 6/2

10YR 7/3

10YR 8/2

10YR 6/3

10YR 7/3

10YR 7/3

10YR 6/3

2.5Y 8/2

10YR 7/3

10YR 7/1

10YR 8/2

10YR 7/4

10YR 7/4

10YR 6/4

10YR 8/2

10YR 7/1.5

10YR 7/4

10YR 6/2

10YR 6/3

10YR 6/3

10YR 6/3

10YR 7/4

10YR 7/3

10YR 7/2

10YR 7/4

10YR 7/2

10YR 7/3

10YR 7/3

10YR 7/4

10YR 7/3

10YR 6/3

10YR 6.5/2

10YR 6/3

10YR 6/3

10YR 6.5/3

10YR 6/4

10YR 7/2

10YR 7/1

10YR 7/1

10YR 6/4

Dryd

consistence

 sh

 so

 so

 sh

 sh

 lo

 sh

 lo

 so

 so

 lo

 h

 lo

 so

 sh

 lo

 lo

 sh

 lo

 sh

 sh

 sh

 sh

 sh

 sh

 sh

 sh

 lo

 lo

 sh

 sh

 sh

 sh

 sh

 sh

 sh

 vh

 vh

 vh

 h

 vh

 sh

 lo

 lo

 vh

 sh

 vh

 sh

 sh

 vh

 sh

 h

 vh

 vh

 lo

 lo

 vh

 vh

 sh

 sh

 sh 

 h

 h

 h

 lo

 lo

 so

 sh

Wetd

consistence

 ss, po

 so, po

 ss, po

 ss, po

 ss, po 

 so, po

 s, po

 so, po

 ss, ps

 ss, ps

 so, po

 so, po

 so, po

 so, po

 so, po

 so, po

 so, po

 so, po

 so, po

 so, po

 ss, ps

 so, po

 so, po

 so, po

 so, po

 so, po

 so, po

 so, po

 so, po

 so, po

 so, po

 so, po

 so, po

 so, po

 so, po

 so, po

 ss, ps

 ss, ps

 s, p

 so, po

 ss, ps

 so, po

 so, po

 so, po

 ss, ps

 so, po

 ss, ps

 ss, ps

 ss, ps

 ss, ps

 so, po

 so, po

 s, ps

 so, po

 so, po

 so, po

 s, p

 ss, ps

 so, po

 ss, ps

 s, ps

 s, ps

 s, ps

 s, ps

 so, po

 so, po

 so, po

 ss, ps

Lowere

boundary

 ne

 a, s

 a, s

 a, s

 a, s

 a, s

 a, s

 a, s

 c, w

 c, w

 a, i

 a, i

 a, w

 a, i

 a, w

 a, i

 a, i

 c, w

 c, i

 c, w

 a, w

 a, w

 c, i

 a, w

 a, i

 ne

 ne

 a, i

 a, i

 c, w

 c, w

 ne

 c, w

 c, w

 c, i

 c, w

 c, w

 g, s

 g, w

 g, w

 g, w

 c, i

 a, s

 c, s

 c, i

 c, w

 c, w

 a, w

 a, w

 g, w

 a, s

 c, w

 c, s

 c, w

 c, w

 a, i

 g, w

 g, w

 a, s

 c, s

 g, w

 c, w

 g, w

 g, w

 c, i

 c, w

 ne

 a, w

Genesis

 Fluvial

 Fluvial

 Fluvial

 Fluvial

 Fluvial

 Fluvial

 Fluvial

 Fluvial

 Lacustrine

 Lacustrine

 Lacustrine

 Lacustrine

 Fluvial

 Fluvial

 Fluvial

 Fluvial

 Fluvial

 Fluvial

 Fluvial

 Burrow fill

 Burrow fill

 Fluvial

 Burrow fill

 Fluvial

 Burrow fill

 Fluvial

 Fluvial

 Fluvial

 Fluvial

 Fluvial

 Fluvial

 Fluvial

 Fluvial

 Fluvial

 Fluvial

 Lacustrine

 Lacustrine

 Lacustrine

 Lacustrine

 Lacustrine

 Lacustrine

 Burrow fill

 Burrow fill

 Burrow fill

 Colluvium

 Colluvium

 Colluvium

 Colluvium

 Colluvium

 Colluvium

 Colluvium

 Colluvium

 Colluvium

 Colluvium

 Colluvium

 Colluvium

 Colluvium

 Colluvium

 Colluvium

 Colluvium

 Colluvium

 Colluvium

 Colluvium

 Colluvium

 Lacustrine

 Lacustrine

 Lacustrine

 Lacustrine

Comments

Silty sand, poorly exposed at bottom of footwall.

Poorly sorted sand and sandy gravel; some imbrication of platy gravels to west.

Silty sand; some iron oxide staining.

Sandy silt; parallel bedded; some iron oxide staining.

Silty, sandy gravel.

Sandy, fine pebble gravel; imbrication of subrounded platy gravels to west.

Massive silt.

Silty, pebbly sand; parallel bedded.

Massive silt; iron oxide staining in bands at upper and lower boundaries, injected with sandy gravel from underlying unit 1.

Silt; contains 3-m-long, subparallel bands of gypsum and carbonate; subangular blocky soil structure in upper 20 cm.

Gravel with sand lenses.

Fine sand lens in gravel.

Medium sand with thin beds of dark minerals.

Coarse sand; crossbedded.

Sandy, fine pebble gravel; crossbedded; imbrication of platy clasts to west.

Medium sand.

Medium sand.

Lenses of fine sand.

Injection of sandy pebble gravel into overlying units 3c and 3d.

None.

Abundant roots.

Injection of sandy gravel, with lenses of medium sand, into overlying unit 4; imbrication of platy clasts to west.

Abundant roots.

Lens of sandy pebble gravel, crossbedded, imbrication of platy clasts.

None.

Sandy pebble-cobble gravel, subangular clasts, poorly sorted, crossbedded, imbrication of platy clasts to west.

Lens of medium sand in pebble-cobble gravel, crossbedded, normally graded, quartz and lithic clasts.

Lens of coarse sand; crossbedded.

Lens of medium sand with thin beds of dark minerals.

Lens of medium sand; crossbedded.

Sandy pebble gravel with 5-mm-diameter pumice clasts, probably reworked from nearby Tertiary volcaniclastic outcrops.

Coarse pebbly sand, poorly exposed at bottom of trench.

Medium sand and lenses of coarse sand with thin beds of dark minerals.

Lens of coarse granular sand.

Thick sand bed.

Lens of very fine sand; contains carbonate stringers.

Massive silt; carbonate in matrix and vertical veins of gypsum.

Massive silt; carbonate in matrix and veins of gypsum; blocky soil structure.

Massive silt; veins of carbonate and gypsum.

Sandy silt lens at base of unit 4.

Massive silt.

With roots.

No roots.

No roots.

Largest of several blocks of unit 4 in colluvial unit 5; rotated westward away from small fault (F2).

Sandy colluvium.

Silty soil A horizon in colluvium; veins of carbonate and gypsum.

Rotated block of sandy soil unit 5b in colluvial unit 6; veins of carbonate and gypsum.

Rotated block of sandy soil unit 5b in colluvial unit 6; veins of carbonate and gypsum.

Silty sediment eroded from unit 4; fills void from post-faulting collapse of block of unit 4 into unit 5.

Lens of massive medium sand, probably injected along fault.

Coarse sandy gravel.

Silty colluvium; veins of carbonate and gypsum.

Silty soil A horizon in colluvium; carbonate in matrix.

Debris wedge of massive pebbly sand.

Debris wedge of massive sandy pebble gravel.

Silty graben-fill sediment; veins of carbonate and gypsum.

Sandy lens near base of silty graben-fill sediment; carbonate in matrix.

Interbedded sand and pebble gravel; parallel bedded; fills small channel on scarp.

Poorly sorted, sandy, silty colluvium.

Poorly sorted, sandy colluvium, veins of carbonate in lower part, abundant roots and organic matter in upper part.

Sandy, silty colluvium; granule pebble bedding inclined 2–3 degrees to east; veins of carbonate.

Massive fine sandy silt, with sparsely distributed pebbles.

Silty, sandy slope wash colluvium.

Sandy gravel injected into overlying unit sp4; overprinted with soil carbonate.

Lens of medium sand; crossbedded; overprinted with soil carbonate.

Sandy pebble and cobble gravel; weakly bedded.

Massive silt; angular blocky soil structure, with vertical veins of carbonate and gypsum.

a

Location: All are located in south wall of trench except sp3 and sp4, which are in south wall of trench site soil pit.

b

Abbreviations: Matrix grain size: v fn, very fine; fn, fine; med, medium; cse, coarse; v cse, very coarse; Largest clast: Na, not applicable (no gravel clasts in unit). c

Color nomenclature from Munsell Color (1994).

d

Consistence: Dry: lo, loose; so, soft; sh, slightly hard; h, hard; vh, very hard; Wet: so, nonsticky; ss, slightly sticky; s, sticky; po, nonplastic; ps, slightly plastic; p, plastic. e

Lower boundary: Distinctness: a, abrupt (<1 cm); c, clear (1–5 cm); g, gradual (>5 cm); Topography: s, smooth; w, wavy; i, irregular; ne, not exposed.

Table 5. Radiocarbon data from the Bog Hot Valley trench.

Field

number

BHV-R01

BHV-R02

BHV-R03

BHV-R04

Laba

number

OS-44943

OS-45467

OS-44875

CAMS 107169

Location

x, y (m)

10.25, 2.18

10.47, 2.25

9.33, 2.38

10.80, 2.65

Unit

number

7e

7e

7c

7e

Reportedb

age (yr B.P.)

3,960 ± 50

3,680 ± 90

3,920 ± 30

3,430 ± 35

Calibrated agec

 (cal yr B.P.)

4,240–4,530 

3,720–4,300 

4,240–4,430

3,580–3,830

13C

(

0/00)

-24.15 

-23.55 

-24.03 

-25 

Comments

Fine disseminated charcoal from lower burn layer.

Fine disseminated charcoal from lower burn layer.

Fine disseminated charcoal from upper burn layer.

Fine disseminated charcoal from upper burn layer.

a

Laboratory identifiers: OS, National Ocean Sciences Accelerator Mass Spectrometry Facility, Woods Hole Oceanographic Institution; CAMS, Center for Accelerator Mass

Spectrometry, Lawrence Livermore National Laboratory.

b

1 sigma analytical uncertainties reported by AMS laboratory.

c

2 sigma calibrated age range; calibration from computer program OxCal (v. 3.10, Bronk Ramsey, 1995, 2001) and the IntCal 2004 atmospheric data set (Reimer and others, 

2004).

1,210

1,250

1,300

ELEVATION (METERS)

 ELEVATION (FEET) 

4,000

4,100

4,200

4,300

Bog Hot Valley 

trench (1,292 m)

Floor of Alvord playa

(pluvial lake basin floor)

Prominent young shoreline complexes

at Miranda Flat (Alvord basin) and 

Pueblo Slough (Pueblo Valley);

probably equivalent to Lake Lahontan

Sehoo highstand (15–16 ka)

Intermediate shorelines

in Bog Hot Valley

Older(?) shoreline

complexes in Bog Hot Valley

Highest young-shoreline

complexes in Bog Hot Valley

and southern Pueblo Valley; 

luminescence ages (table 2) from

trench (BHV-T02) and Pueblo Valley

soil pit (PV-T01) suggest these features

formed 17–18 ka.

1,308 m

1,297 m

1,286 m

1,291 m

1,282 m

1,219 m

1,301 m

1,295 m

1,279 m

17 18 19 20 21 22 23 24 25 26 27

METERS

METERS

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

0

1

2

3

4

5

6

7

0

1

2

3

4

5

6

7

28 29 30 31 32 33 34 35

17 18 19 20 21 22 23 24 25 26 27

METERS

METERS

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

0

1

2

3

4

5

6

7

0

1

2

3

4

5

6

7

28 29 30 31 32 33 34 35

1

-24 -23 -22 -21

METERS

EAST WEST

METERS

-20 -19 -18 -17 -16

2

3

1

2

3

1

-24 -23 -22 -21

METERS

METERS

-20 -19 -18 -17 -16

2

3

1

2

3

METERS

METERS5

10

0

-20 -15 -10 -5 0 5 10 15 20 25 30 35 40 45 50

BHV-T01

(table 2)

3,690 ± 360 yr

6,050 ± 260 yr

6,140 ± 310 yr

3,930 ± 270 yr

11,130 ± 360 yr

17,870 ± 1,140 YR

3,690 ± 360 yr

6,050 ±260 yr 260 yr

6,140 ± 310 yr

11,130 ± 360 yr

17,870 ±1,140 YR 1,140 YR 1,140 YR

BHV-T04

(table 2)

BHV-T04 BHV-T04

(table 2) (table 2)

BHV-T04

(table 2)

3,930 ±270 yr 270 yr

4,790 ± 830 yr

4,790 ±830 yr 830 yr

17,360 ±4,120 yr 4,120 yr

4,240-4,430 cal yr B.P.

3,580-3,830 cal yr B.P.

4,240-4,530 cal yr B.P.

3,720-4,300 cal yr B.P.

4,240-4,430 cal yr B.P. 4,240-4,430 cal yr B.P. ,240-4,430 cal yr B.P.

3,580-3,830 cal yr B.P. 3,580-3,830 cal yr B.P. ,580-3,830 cal yr B.P.

4,240-4,530 cal yr B.P. 4,240-4,530 cal yr B.P. ,240-4,530 cal yr B.P.

3,720-4,300 cal yr B.P. 3,720-4,300 cal yr B.P. ,720-4,300 cal yr B.P.

BHV-T01

(table 2)

x

x

x x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x x

x

x

x

x x

x

x

x x

x

x x

x

x

x

x x

x x

x

x

x

x

x

x

x

x x

x

x

x

x x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

14E

20E

5E

6E

36E

39E

20E

21E

33E

29E

68W

27W 16E

9W

2W

13W

4W

19E

17E

4

K

7e

K K

4

3f

3g

3e

1f

1f

1h

1i

3c

2a

2a

2b

3d

3b

4

K

K

4

K

7e

K K

4

3f

3f

3g

3e 3g

7e

7e

8

7c

7d

7d

7d

6b

6a

5b

5c

5d

6a

5a

4blk 4blk 4blk

4blk

1b

1b

1a

1d

1d

1c

1c

1c

1b

1e

1e

1f

1g

1g

1f

1f

1h

7b

1i

3c

2a

2a

2b

3d

3b

4

4

3d 3c

3d 3d

3b

3a

2b

4

6b

7a

7e

k

K

K

K

K

K

K

K

K

4

4

5blk

3f

3g

3g

7e

7e

8

7c

7d

7d

7d

6b

6a

5b

5c

5d

6a

5a

4blk 4blk 4blk

4blk

1b

1b

1a

1d

1d

1c

1c

1c

1b

1e

1e

1f

1g

1g 7b

6b

7a

7e

k

K

4

4

5blk

5blk

4

3d 3c

3d 3d

3b

3a

2b

4

K

K

K

K

K

sp4

sp4

sp3

sp3

sp4

sp4

sp3

sp3

5blk

Pebbly silt

(bioturbated loess)

Pebbly silt

(bioturbated loess)

Coarse sand oarse sand

Coarse sand oarse sand

Pebble gravel ebble gravel

Medium to coarse sand

and pebble gravel

Medium to coarse sand

and pebble gravel

Fine to coarse

sand

Fine to coarse

sand

3g

EXPLANATION OF TRENCH LOGS

Slope wash colluvium 

Fault-scarp colluvium from most recent faulting event

Fault-scarp colluvium from penultimate faulting event

Fault-scarp colluvium from oldest faulting event

Lacustrine silt; labeled "sp4" in soil pit

Fluvial sand and gravel; labeled "sp3" in soil pit 

Lacustrine sandy silt, sand, and gravel 

Fluvial gravel

Subunits (see table 3)

Krotovina (burrow fill)

Block in colluvial unit

Eroded fault scarp free face

Fault—Arrows indicate direction of relative movement

Contact—Dashed where gradational

Radiocarbon age (calibrated)

Apparent dip of bedding

Unit description location (table 3)

Luminescence age

Bedding

Charcoal bed (burn layer) Lacustrine deposits of

pluvial Lake Alvord

Post-lake colluvium

Pre- and intralake

fluvial deposits

5blk

5E

8

2

1

3, sp3

4, sp4

5

6

7

K

4,420 ± 480 yr

Luminescence sample, age likely in error BHV-T01

x

3,580-3,830 

cal yr B.P.

NEVADA

OREGON

KILOMETERS

0 1

BHV-5

Latest 

 Quaternary

 fault (<15 ka)

Late 

 Quaternary

 fault (<130 ka)

Pluvial Lake Alvord

 shoreline remnant

Quaternary

 fault (<1.6 Ma)

Fault scarp

 profile site

U067 Geodetic

 station

Photograph

 location

Trench

 site

EXPLANATION

Possible additional area of

pre-late Pleistocene lakes 

(raised by sedimentation)

Late Pleistocene overflow Area of late Pleistocene

lakes (not all shown)

Maximum known area of 

pre-late Pleistocene lakes 

(not all basins explored)

EXPLANATION

FAULT AGES

EXPLANATION

Historic

Latest Quaternary (<15 ka)

Late Quaternary (<130 ka)

Late and middle

 Quaternary (<750 ka)

Quaternary (<1.6 Ma)

OREGON

NEVADA

KILOMETERS

0 50

a-g

KILOMETERS

0 50

80

80

95

140

Pueblo Valley

Ponded lagoon

sediment

Barrier bar

Soil pit

Wave-cut

shoreline

?

118°37'30" 118°32'30"

42°

41°56'

KILOMETERS

0 1

Late

 Quaternary

 fault (<130 ka)

Pluvial Lake Alvord

 wave-cut shoreline

Pluvial Lake Alvord

 barrier bar crest

Soil pit location

EXPLANATION

Profile BHV-12

Scarp height: 3.3 m

Surface offset: 2.6 m

Soil profile S2

(table 1)

Profile BHV-1

Scarp height: 4.3 m

Surface offset: 4.3 m

Max. slope angle: 15.5°

No vertical exaggeration

Same datum as trench logs

EAST WEST

Trench outline

Soil pit outline Fault zone F1

Winnemucca innemucca

Orovada

Lovelock ovelock

Burns

Junction Junction

Burns

Junction

McDermitt cDermitt Denio

Profile BHV-2

Scarp height: 3.8 m

Surface offset: 3.8 m

Profile BHV-3

Scarp height: 4.5 m

Surface offset: 3.5 m

Profile BHV-13

Scarp height: 5.1 m

Surface offset: 4.6 m

Profile BHV-4

Scarp height: 4.1 m

Surface offset: 4.0 m

Profile BHV-5

Scarp height: 4.2 m

Surface offset: 4.2 m

Profile BHV-6

Scarp height: 3.3 m

Surface offset: 2.9 m

Profile BHV-8

Scarp height: 3.7 m

Surface offset: 3.1 m

Profile BHV-9

Scarp height: 2.2 m

Surface offset: 1.9 m

Profile BHV-10

Scarp height: 2.8 m

Surface offset: 2.5 m

Profile BHV-11

Scarp height: 2.4 m

Surface offset: 2.0 m

No vertical exaggeration

No vertical exaggeration

No vertical exaggeration

No vertical exaggeration

No vertical exaggeration

No vertical exaggeration

No vertical exaggeration

No vertical exaggeration

No vertical exaggeration

No vertical exaggeration

No vertical exaggeration

Figure 7. Fault scarp profiles in Bog Hot Valley. See figure 3 for profile locations and table 4 for additional slip data. 

EAST WEST EAST WEST

Profile BHV-7

Scarp height: 2.5 m

Surface offset: 2.2 m

No vertical exaggeration

EAST WEST

EAST WEST

F1

F2 F3

F1

F2 F3

Pine 

Forest Range

Pine 

 Forest 

 Range

Pueblo Mountains

Pine Forest Range

TRENCH LOGS AND SCARP DATA FROM AN INVESTIGATION OF THE STEENS FAULT ZONE, BOG HOT VALLEY AND PUEBLO VALLEY, HUMBOLDT COUNTY, NEVADA

By

Stephen F. Personius (personius@usgs.gov),1 Anthony J. Crone,1 Michael N. Machette,1 Jai Bok Kyung,2 Hector Cisneros,3 David J. Lidke,1 and Shannon A. Mahan1

2006

 

INTRODUCTION

This report contains field and laboratory data from a study of the Steens fault zone near Denio, Nev. The 200-km-long Steens fault 

zone (figs. 1 and 3) forms the longest, most topographically prominent fault-bounded escarpment in the Basin and Range of southern 

Oregon and northern Nevada. The down-to-the-east normal fault is marked by Holocene fault scarps along nearly half its length, including 

the southern one-third of the fault from the vicinity of Pueblo Mountain in southern Oregon to the southern margin of Bog Hot Valley 

(BHV) southwest of Denio, Nev. We studied this section of the fault to better constrain late Quaternary slip rates, which we hope to 

compare to deformation rates derived from a recently established geodetic network in the region (Hammond and Thatcher, 2005). We 

excavated a trench in May 2003 across one of a series of right-stepping fault scarps that extend south from the southern end of the 

Pueblo Mountains and traverse the floor of Bog Hot Valley, about 4 km south of Nevada State Highway 140 (fig. 3). This site was 

chosen because of the presence of well-preserved fault scarps, their development on lacustrine deposits thought to be suitable for 

luminescence dating, and the proximity of two geodetic stations that straddle the fault zone. We excavated a second trench in the 

southern BHV, but the fault zone in this trench collapsed during excavation and thus no information about fault history was documented 

from this site. We also excavated a soil pit (fig. 2) on a lacustrine barrier bar in the southern Pueblo Valley (PV) to better constrain the age 

of lacustrine deposits exposed in the trench. The purpose of this report is to present photomosaics and trench logs, scarp profiles and slip 

data, soils data, luminescence and radiocarbon ages, and unit descriptions obtained during this investigation. We do not attempt to use the 

data presented herein to construct a paleoseismic history of this part of the Steens fault zone; that history will be the subject of a future 

report.

ACKNOWLEDGMENTS

This research was supported by the Earthquake Hazards Reduction Program of the U.S. Geological Survey (USGS) under a 

Memorandum of Understanding between the Central Geologic Hazards Team of the USGS and the Winnemucca District Office of the 

U.S. Bureau of Land Management (BLM). The authors wish to thank personnel of the Winnemucca District Office for assistance in 

conducting this research on BLM lands. The report was improved by comments from reviewers Kathy Haller and William Shulz.

RADIOCARBON AND LUMINESCENCE AGE DATA

We obtained four radiocarbon samples from two burn layers in the youngest fault scarp colluvium (unit 7) in the trench (table 5). The 

samples yielded calibrated ages indicating these sediments were deposited about 4 ka. 

We used luminescence dating techniques to determine the ages of lacustrine and colluvial sediments exposed in the trench and soil pits 

(see logs and table 2). TL (thermoluminescence), IRSL (infrared stimulated luminescence—a type of optically stimulated luminescence 

(OSL) unique to feldspars), and blue-light OSL techniques date the last time sediment is exposed to sunlight, presumably during deposition 

(Berger, 1988; Forman and others, 2000). Sampling was conducted with tubes of plastic electrical conduit driven into the freshly cleaned 

trench and pit walls; after extraction, sample tubes were sealed with plastic tape and stored in airtight plastic bags. Most dose rates were 

determined in situ with an Exploranium GR-256 gamma ray spectrometer placed in expanded sample holes drilled in the walls after 

sampling was completed. Field moisture contents of 1–20 percent by weight were determined for each sample in the laboratory. A 

polymineralic, fine-silt-size (4–11 mm) fraction was isolated for the TL and IRSL samples, and a fine-sand-size (90–250 mm) quartz fraction 

was isolated for OSL sample PV-T01. Samples were subjected to combinations of sunlight sensitivity tests, anomalous fading tests (Wintle, 

1973), total bleach and partial bleach experiments for TL (Wintle and Huntley, 1980; Singhvi and others, 1982), and additive dose 

experiments for IRSL (Aitken, 1998) (table 2). Anomalous fading tests showed that the TL and IRSL samples exhibited varying amounts 

of fading, so ages were corrected using the anomalous fading correction technique of Huntley and Lamothe (2001). With three 

exceptions, our luminescence ages are generally consistent and in stratigraphic order. The colluvial sediments exposed in the trench were 

deposited about 4–11 ka. The lacustrine and fluvial sediments were deposited 16–20 ka.

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Huntley, D.J., and Lamothe, M., 2001, Ubiquity of anomalous fading in K-feldspars and the measurement and correction for it in optical 

dating: Canadian Journal of Earth Sciences, v. 38, p. 1093–1106.

Machette, M.N., Haller, K.M., Dart, R.L., and Rhea, S.B., 2003, Quaternary fault and fold database of the United States: U.S. Geological 

Survey Open-File Report 03–417 (online database at http://earthquake.usgs.gov/regional/qfaults/).

Munsell Color, 1994, Munsell soil color charts: New Windsor, N.Y., Kollmorgen Corp., Macbeth Division.

Personius, S.F., Dart, R.L., Bradley, L.A., and Haller, K.M., 2003, Map and data for Quaternary faults and folds in Oregon: U.S. 

Geological Survey Open-File Report 03–095, 581 p., 1 sheet, scale 1:750,000.

Reheis, M., 1999, Extent of Pleistocene lakes in the western Great Basin: U.S. Geological Survey Miscellaneous Field Studies Map 

MF-2323, 1 sheet, scale 1:800,000.

Reimer, P.J., Baillie, M.G.L., Bard, E., Bayliss, A., Beck, J.W., Bertrand, C.J.H., Blackwell, P.G., Buck, C.E., Burr, G.S., Cutler, K.B., 

Damon, P.E., Edwards, R.L., Fairbanks, R.G., Friedrich, M., Guilderson, T.P., Hogg, A.G., Hughen, K.A., Kromer, B., McCormac, 

F.G., Manning, S.W., Bronk Ramsey, C., Reimer, R.W., Remmele, S., Southon, J.R., Stuiver, M., Talamo, S., Taylor, F.W., van der 

Plicht, J., and Weyhenmeyer, C.E., 2004, IntCal04 terrestrial radiocarbon age calibration, 26–0 ka BP: Radiocarbon v. 46, p. 

1029–1058.

Singhvi, A.K., Sharma, Y.P., and Agrawal, D.P., 1982, TL dating of dune sands in Rajasthana, India: Nature, v. 295, p. 313–315.

Soil Survey Staff, 1999, Soil Taxonomy (2d ed.): U.S. Department of Agriculture Agricultural Handbook no. 436, 869 p.

Wintle, A.G., 1973, Anomalous fading of thermoluminescence in mineral samples: Nature, v. 245, p. 143–144.

Wintle, A.G., and Huntley, D.J., 1980, TL dating of ocean sediments: Canadian Journal of Earth Sciences, v. 17, p. 348–360.

Lake

Alvord

Lake

Alvord

 Lake

Coyote

 Lake

Coyote

OwyheeOwy

R

hee

iver R

119° 118°

42°

42.5°

OREGON

NEVADA

Denio

Lake Lahontan ahontan

BHV-8

BHV-11

BHV-10

BHV-13

BHV-6

BHV-5

BHV-4

BHV-9

BHV-1

Bog Hot Valley

trench site

Collapsed 

trench site

BHV-2

BHV-3

BHV-7

BHV-12

N067

U067

Road Canyon

Cherry Gulch

Steens fault zone

Figure 3. Map of Quaternary faults and lacustrine shoreline features in Bog Hot Valley. Faults and shoreline features (shorelines and barrier bars) are from airphotographs and field reconnaissance during

this study. Geodetic stations are from Hammond and Thatcher (2005).

Photograph 3

Photograph 1

Photograph 5

Denio

Alder Creek

Craine Creek

Thousand Creek

Photograph 4

Photograph 2

140

140

SCIENTIFIC INVESTIGATIONS MAP 2952

Version 1.0

Pueblo Valley

Alvord 

basin

Alvord basinAlvord 

basin

Steens fault zone Steens fault zone Steens fault zone

Pueblo

Mtn

Pueblo

Mtn

Bog 

 Hot Valley

Pueblo ValleyPueblo Valley

Soil profile S4 (table 1)

Stadia rod

PUEBLO VALLEY SOIL PIT

Area of

fig. 2

Area of

fig. 2

Area of

fig. 3

Area of

fig. 3

BHV

PV

No vertical exaggeration

No vertical exaggeration

Figure 2. Map of Quaternary faults and lacustrine shoreline features in southern Pueblo Valley. Faults and shoreline

features (wave-cut shorelines and barrier bar) are from airphotographs and field reconnaissance during this study; note 

location of soil pit on crest of barrier bar.

Pueblo Slough

Miranda Flat iranda Flat

Figure 5. Elevation plot of selected pluvial Lake Alvord shoreline features in Bog Hot Valley, southern 

Pueblo Valley, and Alvord basin. The history of pluvial Lake Alvord is poorly known, but reconnaissance 

studies indicate an overflow flood event that lowered the lake level from an unknown elevation to about the 

1,280-m level sometime in the late Pleistocene (Hemphill-Haley, 1987; Reheis, 1999; Carter and others, 

2006). Assuming that Lakes Alvord and Lahontan had similar climatic responses, well-developed 

Lahontan-Sehoo-equivalent shoreline complexes at the 1,279- to 1,282-m level in the Bog Hot Valley and 

Alvord basin probably were abandoned in the latest Pleistocene (15,000–16,000 calibrated yr B.P.; Adams 

and Wesnousky, 1999). In Bog Hot Valley and southern Pueblo Valley, young shoreline features indicate 

Lake Alvord reached an elevation of 1,295–1,297 m, and perhaps higher, before the flood event reduced 

the lake (probably in stages) to 1,279–1,282 m. The Bog Hot Valley trench lies at an elevation of 1,292 

m, so lacustrine sediments exposed in the trench predate the flood event and thus were deposited some 

time before 15–16 ka. Luminescence samples BHV-T02 and PV-T01 (table 2) indicate the flood probably 

occurred some time after 17–18 ka.

Area of

fig. 2

Area of

fig. 2

Area of

fig. 3

Area of

fig. 3

Figure 4. Extent of pluvial lakes in the vicinity of Denio, Nev. (modified from Reheis, 

1999). Note locations of Pueblo Valley (PV) and Bog Hot Valley (BHV) at southern end of 

Lake Alvord, which had no direct connection to Lake Lahontan during the late Pleistocene. 

Orange arrows on east side of Lake Alvord show route of probable late Pleistocene 

overflow flood into Lake Coyote and Owyhee River (Carter and others, 2006). 

Figure 1. Regional map of Quaternary faults. Faults in the northern part of the map are from Personius and others (2003); 

faults in the southern part of the map are from the Quaternary fault database of USGS (Machette and others, 2003).

Figure 6. Topographic profile of fault scarp at Bog Hot Valley trench site (fig. 3). Note locations of trench and soil pit. Scarp nomenclature from Bucknam and Anderson (1979).

F1

Photograph and interpreted line drawing of soil pit excavated in crest of pluvial lacustrine barrier bar on eastern margin of Pueblo 

Valley, 23 km northeast of BHV trench site (fig. 2). Pit exposed well-stratified lacustrine sands and gravels, overlain by pebbly silts 

probably deposited as loess after lake level retreat. Note locations of OSL sample PV-T01 (table 2) and soil profile S4 (table 1). 

Stadia rod numbers and tick marks in decimeters. 

Soil profile S2

(table 1)

Soil profile S1

(table 1)

Soil profile S1

(table 1)

Soil profile S3

(table 1)

Soil profile S3

(table 1)

Manuscript approved for publication October 18, 2006

Any use of trade names is for descriptive purposes only and does not

imply endorsement by the U.S. Government

This map was produced on request, directly from digital files, on an electronic plotter

For sale by U.S. Geological Survey Information Services, Box 25286, Federal Center, 

Denver, CO 80225

1-888-ASK-USGS

A PDF for this map is available at http://pubs.usgs.gov/sim/2006/2952

LOGS OF TRENCH AND SOIL PIT EXPOSURES AT BOG HOT VALLEY TRENCH SITE AND PUEBLO VALLEY SOIL PIT SITE (LOGS SHOWN WITH AND WITHOUT PHOTOMOSAICS)

No vertical exaggeration

Same datum as trench logs

OREGON

NEVADA

Steens fault zoneSteens fault zone

Steens fault zone

TRENCH SITE SOIL PIT

1

U.S. Geological Survey, Denver, CO 80225

2

Korea National University of Education, Chongwon-Gun, South Korea

3

Universidad Nacional de San Luis, San Luis, Argentina

Photograph 5. View (looking southeast) of several basalt boulders on floor of (dry) 

Continental Lake (fig. 3). Numerous large boulders such as these probably were 

shaken loose from outcrops and rolled down the steep eastern flank of the Pueblo 

Mountains (off right side of photo) as a result of strong ground motions from one or 

more recent large-magnitude earthquakes on the southern Steens fault zone.

Photograph 4. View (looking north) of 5-m-high basalt boulder on eastern flank of 

Pueblo Mountains (fig. 3). This and other large boulders probably were shaken loose 

from outcrops and rolled to their present positions as a result of strong ground 

motions from one or more recent large-magnitude earthquakes on the southern 

Steens fault zone.

Photograph 1. View of Bog Hot Valley trench site, looking northwest (fig. 3).

Photograph 3. View (looking southwest) of 4- to 5-m-high fault scarps (between 

arrows) on floor of Bog Hot Valley (fig. 3). Trench site is off left side of photograph.

Photograph 2. View (looking north along strike) of several right-stepping fault scarps 

(arrows) on floor of Bog Hot Valley (fig. 3). Hills in the distance are the southern end 

of the Pueblo Mountains (note west-tilted bedrock). Red line is generalized trace of the 

southern Steens fault zone along the Pueblo Mountains.

119° 117°

43°

40°

41°

42°

118°

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118°51' 118°45' 118°37'30"

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41°52'30"

41°45'

U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY