62 aX REPORT—18638. 
chlorite, and small crystals of garnet. This granite occurs imme- 
diately beside the limestone marble of Dunlewy quarry. 
XV.—Annagary.—A feldspathic paste, with large crystals of orthoclase and 
fragments of quartz: contains also crystals of sphene, locally 
abundant (and occasional hornblende(?) in 1 in. crystals). It is 
found beside the limestone, whenever the latter comes in contact 
with the granite, as at Annagary, Glenleheen, and Barnesbeg. 
XVI. Strontian, Argyllshire.—This granite is somewhat like that of Ardara 
in appearance, and also like the black gneissose granite, which 
is found asa variety at Glen. It is medium-grained, and con- 
tains :-— 
(a). Quartz. 
(4). Feldspar ; white (oligoclase), having the characteristic strie. 
(c). Black mica; abundant. 
XVII. Tobermory, Mull—aA coarse-grained granite, resembling the coarser 
varieties of the typical granite of Donegal. It contains— 
(a). Quartz; abundant. 
(6). Pink orthoclase ; large crystals (4 in. by 1 in.). 
(c). White oligoclase ; striated. 
(d). Black mica; not abundant. 
(e). Sphene facets; occasional. 
The rocks whose analyses are contained in the above Table are hardly to be 
considered as all true granites. Nos. [V. and XIII. are rather to be considered 
gneiss than granite, and No. XV. is a feldspathic paste ; but in the mode of 
their occurrence they do not differ from the granites, and it is impossible to 
say exactly where the granite begins and the gneiss ends. 
Tasrs VI.—Chemical Composition of Donegal Syenites*. 
Alumina. 
iron, 
| peroxide. 
Tron, 
protoxide 
ime 
Magnesia. 
da, 
Potash 
Manganese, 
protoxide. 
Water, 
Totals 
| Silica. 
I. Lough Anure....../49-20|18'82 7°12 1:95 | 9°72 7-11 1°92 1-72 [1-00 [120] 99:26 
TI. Kilrean, near } |4 4.40 |25-00 \6-45 |2-11 110-17 '3°51 |2'58 2-66 0°84 [1-08 | 98:80 
SATS ook tves 5 
III. Doonan Hill...... 50:08 |18-84 |7-05 |1°03 |12°37 6°57 |2°39 |0°57 0°88 (0°80 |100°58 
TY. Locality unknown 58-04 |16:08 |8:27 0°45 6°52 |2:94 |4°65 j2°21 |1°12] ... |100°28 
I. A medium-grained syenite or crystalline greenstone, composed of small 
plates of black mica with hornblende aggregated together, and of 
a feldspar which seems to be oligoclase, 
II. A coarse-grained syenite, containing— 
(a). Long crystals of green hornblende. 
(b). White feldspar. 
(c). Specks of iron-pyrites. 
In addition to the composition given in the analysis, the rock 
contained 1-078 per cent. of sulphur, which no doubt was present 
in the form of pyrites. 
* For a description of the relations of these rocks to the other rocks of the county, see 
p. 48 e¢ seq. 
