ANALYSES OF ROCKS, V. S. GEOLOGICAL SURVEY. 
351 
CLAY8, SOILS, ETC. 
MASSACHUSETTS. 
Clays and soils from Martinis Vineyard, collected by N. S. Shaler. 
See 7th Ann., p. 303. Analyses by F. W. Clarke, record Nos. 439, 440, 
441. 44^, 443, 444, 445, 446, 454, and 455. Partial analyses only. 
A. Average sample of white clay, east end of Chilmark Cliffs. 
B. Average sample of clays, Weyquosque series, Chilmark Cliffs. 
C. Average sample of line clay and soil, east end of Weyquosque 
CI ills. 
I). Sandy white clay, south end of Gay Head Cliffs. 
E. Average sample of line white clay, south end .of Gay Head Cliffs. 
A. 
n. 
c. 
]>. 
E. 
Si0 2 
82. 95 
18.45 
trace 
none 
61. 76 
25. 85 
1.95 
.51 
1.88 
8.01 
5. 70 
trace 
70.81 
20. 67 
1. 99 
trace 
1.28 
1.67 
8.89 
none 
56.19 
80. 65 
t race 
none 
10. 79 
none 
2. 45 
7:;. 40 
A1 2 3 , Fe 2 3 
MgO 
19. 06 
trace 
baO 
Na 2 < ) 
none 
.70 
K 2 
.78 
Ignition 
8.47 
none 
o. 36 
P.O. 
none 
so., 
none 
99. 87 
100.17 
99. 76 
100. 08 
100. 81 
F. Average sample of clay, north end of Gay Head Cliffs. 
G. Average sample of southernmost red clays, Gay Head. 
II. Brown clay, south of light-house, Gay Head Cliffs. 
I. Average sample of red clay from the grcensand, north end of Gay 
Head. 
J. Pyritiferous clay, central part of Gay Head section. 
Si0 2 
A1 2 3J Fe 2 3 
MgO 
CaO 
N:i.,<> 
K 2 
Ignition 
P a 6 
49. 19 
39. 77 
trace 
none 
11. 17 
none 
100. 43 
G. 
ii. 
I. 
57. 50 
56. 62 
55. 93 
31.21 
31.24 
83.51 
.20 
1.97 
.19 
. 19 
trace 
none 
} .40 
.40 
mulct. 
2. 70 
undet. 
9. 83 
7.57 
9. 98 
none 
none 
Qone 
99.33 
100. 56 
99.61 
72. 74 
21.46 
trace 
none 
5.69 
none 
99. 89 
