48 
BULLETIN 61, U. S. DEPAETMENT OF AGBICULTTJBE. 
able beds of salines than marshes of the first type. Descriptions of Searles and 
Columbus Marshes, Railroad and Dixie Valleys, Sand Springs Flat, and Sevier Lake 
follow. 
SEARLES MARSH. 
Searles Marsh lies in the northwestern part of San Bernardino County, Cal., about 
30 miles northeast of Randsburg. It lies in a drainage basin of 4,850' square miles 
area. C. E. Dolbear states that the area of the central depression is about 62.5 square 
miles. This would give a ratio of 77.6 square miles of basin area to 1 square mile of 
central depression area. The lowest part of the depression is 12 square miles in area, 
and is occupied by a smooth, hard floor of salt (PI. Ill, fig. 2). Portions of the 
area are covered by debris; other portions by efflorescences and crusts from a fraction 
of an inch to several feet in thickness; and other portions are covered with clay muds 
which are in part dried out and firm and in part are soft. Plate IV, figure 1, shows a 
trona reef in the northeastern part of the marsh. De Groot * reports results of a 
boring and shows a section of the marsh. _ Dolbear 2 quotes the results of two bores, 
one in the central salt area and the other in the marginal area outside of the salt bed. 
Section of Searles Marsh (De Groot). 
Depth. 
2 feet Salt and thenardite. 
4 feet Clay and volcanic sand with some hanksite. 
8 feet Volcanic sand and black clay with bunches of trona. 
8 feet Volcanic sand containing glauberite, thenardite, and a few crystals of 
hanksite. 
20 feet Mud smelling of hydrogen sulphide and containing layers of glauberite, 
soda, and hanksite. 
28 feet Solid trona overlain by a thin layer of very hard material. 
2304-feet Clay, mixed with volcanic sand and permeated with hydrogen 
sulphide. 
Analyses of samples from borings in Searles Lake. 
[Analyses by Dolbear.] 
Depth. 
Insol. 
NaCl. 
Xa 2 S0 4 . 
NatCOi. 
NaHCOs. 
Xa 2 B 4 7 . 
HjO. 
Feet. 
P.ct. 
P.ct. 
P.ct. 
P.ct. 
P.ct. 
P.ct. 
P.ct. 
0-18 
0.2 
79.7 
7.6 
3.2 
0.0 
Tr. 
3.3 
18-25 
1.4 
44.0 
30.5 
14.8 
2.5 
1.0 
5.8 
25-30 
1.4 
47.3 
28.1 
10.6 
.0 
2.0 
10.6 
30-35 
3.0 
42.7 
17.1 
19.1 
5.9 
2.0 
10.2 
35-50 
1.4 
43.5 
22.3 
9.5 
2.5 
0.0 
15.3 
50-65 
Tr. 
82.8 
10.6 
3.2 
.8 
Tr. 
2,6 
65-79 
Tr. 
19.0 
7.3 
40.3 
18.5 
.5 
14.4 
Analyses of samples from borings outside of salt-bed area. 
[Analyses by Dolbear.] 
Depth. 
Insol. 
XaCl. 
Xa 2 S0 4 . 
Xa 2 C0 3 . 
>"aHC0 3 . 
X3-B 4 7 . 
H 2 0. 
Feet. 
P.ct. 
P.ct. 
P.ct. 
P.ct. 
P.ct. 
P.ct. 
P.ct. 
0-13 
13-20 
Mud. 
8.3 
66.8 
I'd"" 
11.7 

5.0 
0.4 
6.8 
20-25 
Tr. 
98.4 
.8 
1.8 
.0 
.0 
.0 
25-30 
1.4 
15.3 
4.7 
38.7 
24.4 
Tr. 
15.5 
30-35 
15.0 
39.6 
2.3 
16.4 
3.4 
5.56 
12.74 
35-40 
33.4 
17.5 
3.9 
14.85 
4.7 
5.6 
20.05 
40-45 
36.0 
9.8 
2.9 
12.5 
.4 
6.57 
26.28 
45-50 
32.5 
9.0 
2.6 
21.2 
3.8 
.0 
30.9 
50-53 
30.7 
8.3 
2.8 
23.3 
7.6 
Tr. 
27.8 
53-55 
31.0 
- 9.0 
2.S 
21.2 
10.9 
.0 
25.1 
55-60 
26.9 
5.8 
1.9 
26.5 
14.3 
Tr. 
24.6 
60-65 
3.2 
4.5 
38.0 
28.6 
10.1 
Tr. 
10.6 
65-70 
6.8 
5.1 
6.8 
43.5 
21.0 
Tr. 
16. S 
70-75 
7.6 
4.0 
2.8 
53.0 
16.0 
.0 
16.6 
1 10th Annual Report, California State Mining Bureau, p. 
2 Engineering and Mining Journal, Feb. 1, 1913, p. 260. 
5 5 5 ■ 
