TABLE 1.Quartz Blue-light OSL Ages for Mason Road Trench.

Sample name % Water K (%) b Th (ppm)b U (ppm)b Cosmic dosec Total Dose Equivalent nd Age

contenta additions (Gy/ka) Rate (Gy/ka) Dose (Gy) (ka) e Nearest calibrated C14 ages

USGS 110 17 (79) 1.16 ± 0.08 7.13 ± 0.37 2.23 ± 0.17 0.20 ± 0.01 2.46 ± 0.07 9.07 ± 0.10 20 (27) 3.69 ± 0.13 MRP3 (0.3 m below) 3375 ± 40 yr

USGS 111 18 (64) 1.65 ± 0.05 6.36 ± 0.53 1.46 ± 0.19 0.19 ± 0.01 1.76 ± 0.09 12.9 ± 0.20 18 (30) 7.30 ± 0.40 MRP8 (immediately below) 7326 ± 60 yr

USGS 113 28 (100) 1.12 ± 0.04 6.45 ± 0.17 1.68 ± 0.15 0.19 ± 0.01 1.69 ± 0.04 24.2 ± 0.44 16 (18) 14.3 ± 0.43 none available

a

Field moisture, with figures in parentheses indicating the complete sample saturation percent. USGS-110 calculated using field moisture, others below or in water table.

b

Analyses obtained using laboratory Gamma Spectrometry (low resolution NaI detector).

c Cosmic doses and attenuation with depth were calculated using the methods of Prescott and Hutton (1994). See text for details.

d

Number of replicated equivalent dose (De) estimates used to calculate the mean. Figures in parentheses indicate total number of measurements made including failed runs

with unusable data.

e

Dose rate and age for fine-grained 250-180 um quartz sand. Linear and exponential fit used on age, errors to one sigma.

Note: USGS 112 yielded no OSL age

Figure 4. View northeastward along Log-1. Upper ladder on steep (53°) 

upper slope, below is a gentler (34°) slope. String grid used to rectify photo 

mosaic of stratigraphic log shown in figure 2.

MRP-6

MRP-7

MRP-5

MRP-4

u40

u30-35

u45

o-bn st sd

bn cl sd st - bn st sd

dk bn cl sd st 

Elevation (approx.) (meter)

Distance (meter)

21

20 

5.6 6.6 7.6 

Figure 3. View westward along Log-2, location shown in figure 1, on east wall of 

south ramp. For explanation of symbols and abbreviation, see figure 2. 

MRP-8

MRP-1

MRP-2

MRP-3

22

21

20 

19 

18

17

16

15

OSL-USGS-111

OSL

USGS-113 OSL-USGS -112

OSL-USGS-110

Elevation (approx.) (meter)

APPROXIMATE SURFACE ELEVATION

MATERIAL REMOVED DURING EXCAVATION

disturbed, fill/plow zone

bn st sd

o-bn st sd

o-bn st sd

dkr bn cl sd st 

bn cl st sd 

dk bn cl sd st 

dk bn sd st cl -sd cl st

dk bn-black st cl 

black st cl 

olive gray st cl 

bioturbated u75 mixed w/ u70

(weak Bt-horizon; 

minor CO3 at base)

(weak A-horizon)

o-bn st sd 

o-bn st sd 

(mod. abund. C03 strings & blebs)

(minor C03 blebs)

(minor C03 blebs)

(cl eluviation, C03 blebs)

( C03 strings)

( C03 strings)

( abundant

large C03 nodules;

 blocky-prismatic)

(no C03)

(blocky, no C03)

(prismatic, no C03)

olive gray st cl w/ lenses of cl sd st 

sandier near base of pit

(prismatic, no C03)

(no C03)

( blocky with

abundant 

C03 strings)

(weakly blocky)

Mason Road Pit

Log-1 of East Wall

2006

gray sd cl st [upper aquifer]

[lower aquifer]

orange sd st

w/ gray clay

(abundant C03 blebs)

THIS PHOTO

SHIFTED

1 METER

TO NORTH

drainage sump

vertical OSL

sample, elev.

14.35-14.95 m

elevation = 14.95 m, Base of Pit 

Unit number

Radiocarbon sample

location (Rectangle

indicates bulk sample) 

u80

MRP-3

ABBREVIATIONS

o, bn, dk

CO3

gc

gv

m

sd

st

cl

orange, brown, dark

carbonate

gray clay

gravel

medium

sand

silt

clay

lt o-bn st sd

lt o-bn st f.-c. sd

c. sd & pea gv

OSL sample location

(Optically Stimulated

Luminescence)

EXPLANATION

u10

u15

u20

u25

u30

u35

u40

u45

u50

u55

u60

u65

u70

u75

u80

u85a

u85b

u85c

Figure 2. Log-1, stratigraphic section at 

location shown in figure 1.Photographic 

images rectified using string grid shown in 

figure 4. OSL and radiocarbon samples are 

further described in table 1 (this sheet) and in 

the accompanying pamphlet.

LOG-1 (figure 2)

Log-2 (figure 3)

22 m

3

16.95

16.95

16.962

16.904

16.981

16.921

17.016

16.956

17.023

16.996

17.084

17.032

17.108

16.918

14

16.989

17.047

16.973

17.051

17.058

17.0 m

17.0 m

16.90 m

2006 Pit

0 1 2 3 4 5 6

Meters

CPT #3

SOUTH RAMP

SUMP

NOTES: Channel base pts. from

differential GPS ±2-3 cm. Contours

in purple (0.05 m) are approximate.

Grid pts 5 and 7 collocated.

Figure 1. Map of 7-m-deep pit excavated in 2006 at location shown in figure 2 of Sheet 1. Log-1, shown by yellow 

rectangle above, shows a stratigraphic section (Fig. 2, this sheet) and locations of radiocarbon and OSL samples. 

Log-2 (figure 3) indicates the locations of additional radicarbon samples. Blue dots are surveyed positions on the 

channel base (that is, of u75) and blue contours are the interpreted shape of the channel (see figure 2 for description 

of unit u75). Upper slope (53°) shown in green; access ramps shown in orange.

Mason Rd Pit 2006

This map was printed on an 

electronic plotter directly from digital 

files. Dimensional calibration may 

vary between electronic plotters and 

between X and Y directions on the 

same plotter, and paper may change 

size due to atmospheric conditions; 

therefore,

scale and proportions may not be 

true on plots of this map.

For sale by U.S. Geological Survey, 

Information Services, Box 25286, 

Federal Center, Denver, CO 80225, 

1-888-ASK-USGS

Available on World Wide Web at 

http://pubs.usgs.gov/of/2012/1011/ 

Any use of trade, firm, or product 

names in this publication is for 

descriptive purposes only and does 

not imply endorsement by the U.S. 

Government 

Manuscript approved for publication January 13, 2012

Logs and Data from Trenches Across and Near the

Green Valley Fault at the Mason Road Site, Fairfield,

Solano County, California, 2006-2009

By

James J. Lienkaemper, Robert R. Sickler, Shannon A. Mahan, 

Johnathan Brown, Liam M. Reidy, and Mindy A. Kimball

2012

Open-File Report 2012-1011

Sheet 4 of 5

Pamphlet accompanies map

U.S. Department of the Interior

U.S. Geological Survey