404 
REV. S. HAUGHTON ON THE JOINT-SYSTEMS OF IRELAND 
Trap Dykes of Systems A and A". 
Bearing. 
Dip. 
Rock. 
Locality. 
5 N. of E. 
50 S. 
Felstone (fyke in slate. 
Rostrevor. 
E.W. 
90 
Greenstone dyke (19 feet wide) in slate. 
Rostrevor. 
5 N. of E. 
90 
Greenstone dyke (12 feet wide) in slate. 
Killowen. 
10N. of E. 
Greenstone in slate. 
Clogh More. 
I 15 N. of E. 
Dolerite in slate. 
Slieve Bawn. 
5 S. of E. 
85 N. 
Felstone porphyry in granite. 
Slieve Bingian (little). 
10 S. ofE. 
90 
Felstone in slate. 
Armer’s Hole. 
20 S. of E. 
90 
Elvan in granite. 
Slieve Bingian. 
Trap Dykes of System C. 
Bearing. 
Dip. 
Rock. 
Locality. 
| ° N.S. 
10 W. of N. 
5 W. of N. 
90 
80 W. 
30 W. 
Basalt dyke in granite. 
Greenstone dyke in slate. 
Syenite in slate. 
Ballymacilreiny. 
Carlingford Mountain. 
Carlingford Pier. 
We have therefore evidence of the existence of the following systems of Joints and 
Dykes in the Mourne and Newry Mountains : — 
I. Primary System : — 
(A). Joints. . . 14° O' N. of E. (Mag.)=39° 40' N. of E. 
II. Conjugate of Primary : — 
(C). Joints. . . 12° 8 ' W. of N. (Mag.) =37° 48' W. of N. 
Dykes. . . 13° 34' „ „ =39° 14' W. of N. 
III. First Secondary System : — 
(A'). Joints ... 45° 0' E. of N. (Mag.)=19° 20' E. of N. 
IV. Conjugate of First Secondary : — 
(C). Joints. . . 46° 26' W.ofN. (Mag.)=17° 54'S. ofE. 
Dykes ... 43° 34' „ „ =20° 46' S. of E. 
V. Second Secondary System : — 
(C"). Joints . . 18° 5' E. of N. (Mag.)=7° 35' W. of N. 
The angles between the Primary and Secondary Systems are 
Between Primary and First Secondary Systems — 
A— A' 31° 0' 7 
C—C' (Joints) 34° 18' 1 = 3 1 ° 46 '. 
C— C' (Dykes) 30° 0 ' J 
Between Conjugate to Primary and Second Secondary-^ — 
C— O' (Joints) 30° 13' 1 0 
C—C" (Dykes and Joints) . . . 31° 39' J “ 3 ° 5 ' 
