Lower Palceozoic Bocks of the South-East of Ireland. 609 



Description of the foregoing Granites. 



No. 1. Cushbawn Hill, 1318 ft. high, near Ballynaclash ; this granite is the most north- 

 westerly of the granite patches, or nearest to the main granite chain; fine-grained 

 granite, composed of quartz, white felspar, white mica, and green mica; both micas 

 in small grains; specific gravity =2'671. 



No. 2. Coolboy, Tinahely, county of Wicklow; remarkable granitic patch, occupying the 

 bottom of a valley, scored out in consequence of the granite rock being softer than 

 the surrounding slate. The bearing of this granite outlier prolonged to the north- 

 east, as shown on the map, would pass right along the direction of No. 3, or Bal- 

 lynaclash granite, leaving Cushbawn Hill somewhat to the north-westward. Gra- 

 nite, fine-grained; consisting of — 



1. Quartz, gray and minutely disseminated. 



2. Black mica, conspicuous, often collecting into flattened nests ; 2-3 in. long 



by 1^ broad, by ith thick. 



3. Very minute specks of white mica. . 



4. White felspar, saccharoid, intimately mixed with quartz, and semitranslu- 



cent. 

 No. 3. Ballynaclash, on same line as No. 2. Fine-grained granite, composed of.— 



1. White mica, in small occasional flakes. 



2. Dark green hornblendic mica, in minute grains, giving a general greenish 



character to the rock. 



3. Quartz, gray, conchoidal, conspicuous. 



4. White opaque felspar, forming the felspathic paste in which the other mine- 



rals are embedded. 



5. Crystals of felspar, of bright watery lustre, translucent; embedded in 4. 

 No. 4. Croghan Enshela, head of Coolbawn brook, N. N. W. ; central mass of deep granite 



of mountain; crystalline; medium-grained; facets of felspar predominating, and 

 giving a character to the rock, which is of a pale-greenish colour, owing to the 

 presence of blackish-green hornblende; the mass is composed of 



1. Quartz, gray, conchoidal, inconspicuous; smothered in felspar. 



2. Hornblende in minute grains. 



3. Felspar in translucent crystals (^th by ith in.), with highly reflecting sur- 



face ; those crystals, which appear to be orthoclase, give a character to the 

 entire rock. 

 No. 5. Croghan Kinshela, near summit; specific gravity = 2-629; brilliant white felspar, with 



gray quartz; stained here and there with patches of chlorite. 

 No. 6. South Base of Arklow Eock Little; fine-grained granite, very white; it occurs in a 

 vein not more than 20 yds. wide, with slate on each side; composed of — 



1. Quartz, distinctly visible in minute grains. 



2. Felspar, opaque, very white, forming the greater portion of the rock mass; no 



distinct crystals. 



3. Very minute grains of very silvery white mica disseminated through the 



rook, giving frequently a silvery lustre to the facets of quartz and felspar. 



No. 7. Bally moty more, near Oulart, containing black mica; specific gravity = 2-659; fine- 

 grained granite. 



No. 8. Ballynamuddagh, near Oulart; coarse-grained granite, containing distinct and large 

 plates of black mica, J^th in. broad ; specific gravity = 2-670. 



