clakke.] CLAYS, SOILS, ETC. 289 
CLAYS, SOILS, ETC. 
MASSACHUSETTS. 
Clays and soils from Marthas Vineyard, collected by N. S. Shaler. 
See 7th Ann., p. 303. Analyses by F. W. Clarke, record Nos. 439, 440, 
441, 442, 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 fine clay and soil, east end of Weyquosque 
Cliffs. 
D. Sandy white clay, south end of Gay Head Cliffs. 
E. Average sample of fine white clay, south end of Gay Head Cliffs. 
A. 
B. 
C. 
I). 
E. 
Si0 2 
. 82. 95 
13.45 
trace 
none 
61.76 
25. 35 
1.95 
.51 
1.83 
3.01 
5.76 
trace 
70.81 
20.67 
1.99 
trace 
1.23 
1.67 
3.39 
none 
56. 19 
30.65 
trace 
none 
73. 46 
19.06 
trace 
none 
.70 
.73 
6.36 
none 
none 
A1 2 3 . Fe 2 3 
MgO 
CaO 
Na 2 
K 2 
Ignition .« 
3.47 
none 
10.79 
none 
2.45 
P 2 5 
S0 3 
99.87 
100. 17 
99.76 
100. 08 
100. 31 
F. Average sample of clay, north end of Gay Head Cliffs. 
G. Average sample of southernmost red clays, Gay Head. 
H. Brown clay, south of light-house, Gay Head Cliffs. 
I. Average sample of red clay from the greensand, north end of Gay 
Head. 
J. Pyritiferous* clay, central part of Gay Head section. 
Si0 2 
A1 2 8 , Fe 2 3 
MgO 
CaO 
Ignition 
PA ... 
p. 
49.19 
39.77 
trace 
none 
11.47 
none 
100. 43 
<;. 
57.50 
31.21 
.20 
.19 
.40 
9.83 
none 
99. 33 
ii 
56. 62 
31.24 
1.97 
trace 
.40 
2.76 
7.57 
none 
100. 56 
55.93 
33.51 
.19 
none 
undet. 
undet. 
9.98 
none 
99.61 
72.74 
21.46 
trace 
none 
o. by 
none 
99.89 
Bull. 168- 
19 
