1855.] ODERNHEIMER PEEL RIVER DISTRICT. 401 



met with at a greater distance. The slate contains also small beds 

 of limestone, which increase in some localities to large masses. 

 Where the soft slate predominates, and also in rare spots nearer the 

 metamorphosed rocks, traces of fossil plants {Lepidodendi'on) have 

 been observed in the slate. The limestone, where it is less metamor- 

 phosed (silicified and brecciated), contains plentiful remains of Corals, 

 which are especially observed on the corroded surface, and generally 

 charged with siliceous matter. Shells are of rare occurrence in the 

 district of my immediate researches. The determination of the species 

 of those fossils I must leave to better authorities at home. 



In the area of the greatest development of igneous and meta- 

 morphosed rocks on both sides of the Peel River, and higher up to 

 the Dividing Range, is the locality of the gold-bearing quartz-veins 

 in this district. These veins are either parallel to the general strike 

 of the rocks (N.N.W. to S.S.E.,— north 30° west to south 30° east), 

 or transverse to the strike (E.N.E. to W.S.W., — east 25° north to 

 west 25° south). The veins are generally of small size, and seldom 

 exceed one foot in thickness ; they occur for the most part in dioritic 

 rock, and in dioritic and siliceous breccia, but appear to be the 

 richest in true diorite. As far as actual trials have shown, the veins 

 are in general not very regular, being often cut oif and shifted, or they 

 lose themselves in small strings in the direction of the strike as well 

 as in that of the dip, widening again at a short distance. In those 

 few veins which are opened by trenches and shafts, the occurrence 

 of gold is confined to the decomposed upper parts or outcrops, 

 especially where these appear disintegrated and partly drifted. 

 "Where the veins become more compact at a greater depth, gold is 

 not visible, but iron-pyrites are observed in more or less quantity. 



I may not be justified by those few instances to form a decided 

 opinion on the formation of the gold, but these very instances leave 

 no doubt in my mind that the gold is derived from auriferous iron- 

 pyrites. The upper parts of the gold-bearing quartz-veins, which 

 have been tried, showed a high degree of decomposition, — the upper- 

 most portion must have undergone a hydro-chemical process ; the 

 quartz appears in loose and often complete crystals newly formed, 

 among which the gold is interlaced with more or less crystalline 

 structure. This crystalline outcrop of the veins has generally been 

 partly drifted. The more compact portions of the outcrop show 

 also some gold as a coating on the surfaces, or in chinks in the 

 mass itself, but not reaching far down, where the vein is less cry- 

 stalline and cavernous. In favourable occasions, however, this de- 

 composition has gone on even to a considerable depth ; but the most 

 auriferous quartz-veins confirm the observation, that gold appears 

 chiefly at the outcropping. Auriferous iron-pyrites in those veins 

 where they occur in sufficient quantity and richness must be looked 

 for in future mining operations. I had the opportunity of studying, 

 in many localities, the decomposition of the upper parts of veins, and 

 I am led to the opinion, that the appearance of gold is most naturally 

 accounted for by such decomposition. Hydrated oxide of iron is 

 abundantly spread over those parts where gold occurs, and the source 



