266 PEOCEEBIIs^GS OF THE GEOLOGICAL SOCIETY. [April 28, 



III. On THE OCCUEKENCE of GoLD. 



All the rocks in whicli gold has recently been discovered in the 

 County of Hastings are comprised within the Laurentian area, known 

 as the Quinte Gold-mining District. The first discoyery of the 

 precious metal was made in 1866, during an unsuccessful search for 

 copper ores. Superficial indications of the occurrence of copper in 

 the township of Madoc had previously led to the prosecution of 

 irregular workings in several locahties ; but none of the explorations 

 had been characterized by any measure of success. At length, 

 however, a specimen was obtained from one of these so-called mines 

 which, although at first mistaken for native copper, was soon found 

 to be native gold. Stimulated by this discovery, further search was 

 prosecuted ; and at the locahty which subsequently became famous 

 as the " Richardson Mine," a considerable quantity of free gold was 

 discovered in two pockets, or irregular cavities, at a depth of about 

 15 feet below the surface. Considerable interest attaches to this 

 mine, not only on account of the large amount of gold which it 

 yielded within a very short space of time, but more especially on 

 account of the peculiar conditions of association under which the 

 metal occurred. 



The E-ichardson Gold Mine is situated on the eighteenth lot of 

 the fifth concession in the township of Madoc. The surrounding 

 rock consists of an epidotic and chloritic gneiss, enclosing a bed of 

 steatitic schist, and associated in certain places with a ferruginous 

 dolomite. A peculiar character is given to this dolomite by the 

 local occurrence of a black carbonaceous substance which, in ex- 

 ternal characters, bears considerable resemblance to a lignite, but 

 which is regarded by Dr. Sterry Hunt as probably an altered form 

 of bitumen. It occurs imbedded in the dolomite, in small irregular 

 fragments, which break with a conchoidal fracture, and present a 

 pitch-black colour and a resinous lustre. Heated in the open air, 

 it readily ignites, burning with little or no flame, and leaving a 

 residue which, in a specimen examined by Dr. Hunt, consisted of 

 " carbonate of lime, with some siliceous and ferruginous matter, in- 

 cluding a quantity of gold." 



This friable carbonaceous substance, in association with ochrey 

 oxide of iron, incrusted the walls of the gold-bearing pockets of 

 the E-ichardson Mine, and formed the matrix through which the metal 

 was chiefly disseminated. It would appear that these pockets are merely 

 expansions of a fissure running along the plane of bedding between the 

 highly inclined rocks of the surrounding country. The contents of 

 these cavities have evidently been derived from the decomposition of 

 the surrounding dolomite; for that rock, as seen by the specimens ex- 

 hibited, contains the disseminated carbonaceous matter, together 

 with free gold, whilst it appears to be sufficiently ferruginous to 

 yield the oxide of iron on decomposition. Whether the carbona- 

 ceous substance has, by its reducing action, played any part in the 

 genesis of the gold is a chemical question on which the writer is 

 not prepared to enter ; but their intimate association in this mine is 



