192

CRYSTALLINE SCHISTS-GNEISS.

crystalline, and has small specks of mica imbedded. 78. Is similar precisely to No.46 ; abounds with minute grains of iron pyrites disseminated. 53. Very similar,without the pyrites. 9. Somewhat coarser or larger grained, but otherwisesimilar. 8. Do., with small scales of mica and traces of felspar. 114. Similar,with patches of bronze-coloured mica. 116. A little deeper in colour, otherwiselike No. 46. 112. Similar, with dark chlorite in small quantity. 111. Slightlyhornblendic, but quartzose. 203. Very similar to 45, 46, &c. 5. Is a dense

chlorite rock, partings of chlorite and fibrous chlorite disseminated, is rudelyschistose. 47 • Is nearly similar; fibrous; light green and minutely crystalline. 70.Hard, quartzose chlorite rock, fibrous. 2. Hard quartz rock, with minute scalesor fibrous partings of chlorite ; pyrites occurs disseminated. 12. Very similar.81. Quartz with chlorite admixed, with small lumps of quartz of greenish colourimbedded, and minute specks of mica. 16. This curious rock seems to bea compound of grey quartz, massive and compact, and numerous, imbedded por-tions (crystalline) of light green or greyish-green actynolite, or hornblende:these are indiscriminately distributed through the rock, and in some cases areaccompanied by small patches of dark mica in scales. 11. A similar rock ; crys-tals smaller but more abundant; quartz of a deeper grey. 15. Differs solely insize of grain, being smaller. 179. Very similar ; patches of dark mica morenumerous and more equally disseminated, while the crystalline masses of horn-blende or actynolite (? felspar,) are less abundant. 180. Similar, quartz isdarker in colour, rock more crystalline ; difference is probably due to the rockbeing less decomposed. 51. Nearly identical with 179; quartz is light grey;occurs in lumpy masses, giving the rock a very uneven or nodular fracture. 90.Very similar. 44. Do., darker in colour and finer grained. 206. The rock isof the same general character, but mica of a dark bronze colour forms thin evan-escent partings, and the quartz is of the same greenish-grey tinge and granularlycompact character. 171. Similar; the thin partings numerous but irregular.166. Differs principally from the larger grained rocks above, in the smallness ofits grain and the more equal intermixture of the ingredients, is decidedly schis-tose and thin bedded. 79. Very dense and hard; but rendered schistose bythin partings of mica in minute scales. 49. Very similar, with numerous smallpatches of carbonate of lime; quartz occurs chiefly in lumpy layers. 31. Essen-tially similar, but fine grained and more nearly homogeneous in aspect. 128.This would by some be called hornblende slate; the rock is schistose; theschistose structure being caused by thin partings of fibrous and silky horn-blende (?), the mass of the rock is however quartz, of a dark colour. It cannotbe truly called schistose, but from the parallel arrangement of the fibres, hassomewhat of that structure. 129 B. More largely crystalline, but essentiallyof the same ingredients ; coated by crystals and crystalline seams of carbonateof lime on the fractures. 209. Is an intimate intermixture of hornblende andquartz, with carbonate of lime arranged parallel to the prismatic planes, and onthe cross fracture exhibiting crystalline planes; thin threads of carbonate oflime also traverse the rock. 211. Similar, but more schistose and more calca-reous. 138. Very similar. 131. Rather lighter in colour; no lime, but thefelspar (crystalline) in greater abundance. 173. Distinctly crystalline, andhaving a crystalline arrangement; essentially, however, of the same ingredients.