O'Eeilly — On Jointing in Rocks about Dublin, S;c. 147 



No. of 

 observed Faults. Dykes, 



Directions. and remarkable Joints. 



Locality where 

 observed. 



38 



77 



79 



80 



91 



223 



225 



226 

 314 

 561 



562 

 165 



Great open joint, 

 Contact of granite and 

 slate rock, 



Great joint, . 



Great fault, with disloca- 

 tion, 



" Sheep Hole " and 

 Greenstone dyke. 



Creek and great joint. 



Great open joint, . 



Dolomite joint, a main 

 one. 



Iron lode. 



Bullock Harbour, 

 Killiney Park, . 



Dalkey Island, . 

 Howth, S. side, 



Malahide Strand, 

 Kimmage Quany, 



Howth, 



Magnetic 

 Bearing. 



38°-39° E."| 

 39° E. 



42° E. 



39° 30' E. 



38°-40° E. 



38°-39" E. 



True 

 Bearing. 



36°-38° E. >18M0' E. 



3o°-38° E. 



41°-42° E. 



41°-42° E. 



42°-43° E. 



40°-45° E. 



33 



Main joint, 





Sandycove, 



44° E. N 





157 



Dyke, . 





Howth, Puck's Kock, 



46°^7° E. , 

 45°^6° E. ** ^^ 



E. 



402 



Dyke in banded shales, . 



Donabate Coast, 



549 



Great joint, with 

 lining, 



clay 



Feltrim Quany, 



43°-44° E. ; 





5 



Joint, 





People's Park, Black- 

 rock, 



53° E. ^ 



1 





51 



Eurite vein, . 





Bullock Quarry, 



''lfl\^rz. 



E. 



251 



Well-marked joint. 





Ireland's Eye, . 



337 



Dolomite dyke. 





Malahide Coast, 



53°-54° E. 





489 



Great calcspar lode. 





Gollerstown Bridge, . 



52° E.J 





395 



Great vertical feldspar 



Donabate Coast, 



67°-68" E. 46° 10' 



E. 





dyke, 











424 



Fault, . 





Donabate Coast, 



75°-76° E. 54° 10' 



E. 



239 



Fault, . 





Ireland's Eye, . 



87°-88° E. 66° 10' 



E. 



204 



Great joint. 





Howth, S. side, 



3°_4° w.-] 





205 



)))>•• 





!) ;; - • 



2°-3° W. 





218 



,, open joint, . 





,, ,, . . 



3° w:>24^40' 



W. 



221 



,, joint. 





,, ,, . . 





225 



Trap rock dyke, 





,, ,, . . 



3°-5° W. 

 3°-5° W.^ 





237 



Fault, . 





Drumleck Bay, 











Howth, 







87 



Great Eurite vein, . 





Dalkey Island, . 



6°-7° W. 27° 50' 



W. 



100 



Eurite vein, . 





Dalkey Island, . 



18°-19°W.^ 





120 



Great joint, . 





Dalkey Quarries, 



18° W. j 





129 

 130 



,, dyke, . 

 Eurite vein, . 





" 



18° W. 1 , , 

 17°-18°W. (^^ ^° 



AV. 



138 



Great joint. 





)> ,, 



]7°-18° W. 

 2r-22° W. , 





136 



„ „ . . 





)) )) 





422 Fault cutting shales, . Donabate Coast, 



B. I. A. TROC, SER. II., VOL. IV. SCIENCE. 



23°-24° W. 44° 50' W, 

 X 



