Holts—The Correlation of Fracture Systems. 17 
detailed observations, from which it is clearly seen that the in¬ 
termediate directions which have greatest importance, while prop¬ 
erly enough described in general terms as northeast and north¬ 
west, fall principally in six and not two series. The comparison 
of the general results determined for the lineaments of the At¬ 
lantic border region with the general directions observed in in¬ 
dividual districts examined by the writer expresses a like result. 
The actual observations made by Mr. Laney have been tabulated 
by the author with the following result. 
N 
CO 
o 
o 
W 
14 
N-S 7 
N 
15° 
E 
62 
N 
30°- 
-40° 
W 1 
N 
30° 
E 
9 
N 
30°- 
-35° 
W 3 
N 
35° 
E 
2 
N 
35° 
W 
1 
N 
o 
o 
-50° 
E 
N 
o 
O 
W 
1 
N 
45° 
E 
8 
N 
45° 
W 
2 
N 
50° 
E 
1 
N 
50° 
W 
2 
N 
55° 
E 
2 
N 
55° 
W 
2 
N 
55° 
w 
1 
N 
60° 
E 
12 
N 
60° 
vv 
10 
N 
65° 
E 
1 
N 
65° 
w 
1 
E-W 8 
N 
o 
O 
00 
E 
1 
In the North Carolina Newark both joints and dikes stand ap¬ 
proximately vertical, and it appears that the dominant direction 
Is N 15° E. The remaining joint series are so oriented as to fall 
into three conjugate sets.. Moreover, the joints observed at any 
locality were found generally to be in pairs corresponding to one 
or the other of the sets. 
The Finger Lakes district of West-Central New York. Mr. 
Charles G. Brown of Ithaca, N. Y., has measured the directions 
of more than 1000 joint planes which occur in the vicinity of 
Ithaca in the basins of the near-lying lakes. In order of rela¬ 
tive numerical importance the joint directions of the district 
are found to be i 1 
N. 20° W. (288), N. 10° W. (139), N. 70°—75° E. (131), 
N. 15°—16° W. (88), N. 60° W. (86), N. 30° E. (68), N. 80° E. 
(62), N. 40° W. (51), N. 4°—6" W. (43), N. 30°-—34° W. (35), 
N. 85° E. (35), and N.—S. (15). These twelve directions in¬ 
clude 941 of the 1,004 measurements and with the exception of 
i Jour. Geol., vol. 13, 1905, pp. 367-374. 
