46 



NATURE 



[Nov. ir, 1880 



but the interpretation of the infinity which occurs in the more 

 comprehensive formula suggests an examination of the stream- 

 lines by which its interpretation becomes obvious, and which 

 proves that even in the case of constant vorticity the motion has 

 a startlingly peculiar character at the place where the translational 

 velocity is equal to the wave velocity. This peculiarity is repre- 

 sented by the annexed diagram, which is most easily understood 



if we imagine the translational velocities at _i' = o and y — aio 

 be in opposite directions, and of such magnitude that the wave 

 velocity is zero ; so that we have the case of standing waves. 

 For this case the stream-lines are as represented in the annexed 

 diagram, in which the region of translational velocity greater 

 than wave-propagational velocity is separated from the region 

 of translational velocity less than wave propagational velocity by 

 a cat's-eye border pattern of elliptic whirls. 



MINERAL RESOURCES OF NEWFOUNDLAND 



/^RES of copper have been found in all the older fonnations 

 ^~' in Newfoundland, from the Laurentian gneiss at the base, 

 to the Carboniferous series at the summit, the qualities of which 

 vary greatly with the age and condition of the rocks with which 

 they are associated. Thus in the Laurentian series the rich ores 

 of variegated and sometimes grey sulphide of copper are more 

 frequent than any other, and are for the most part in white 

 quartz veins intersecting the strata ; but while the?e ores have in 

 many cases been found on analysis to yield at the rate of from 50 

 to 70 per cent, of metal, the quantities available at any one place 

 hitherto tested have never yet been found sufficient to warrant 

 an outlay of capital. 



In the succeeding series, which I conceive to be the equivalent 

 of the Iluronian of Canada, and have provisionally called 

 iiiternicdiatt\ as being intermediately situated between rocks of 

 the Laurentian and Primordial Sihuian ages, very rich ores of 

 copper are likewise well known at many parts, chiefly in white 

 quartz veins, and also in faults and dislocations, particularly near 

 the junction with the fossiliferous Primordial, in which cases the 

 indications may sometimes be regarded as favourable for the 

 probable future development of mines. Several attempts have 

 already been made in this direction at various parts of the 

 distribution of the series, but except at a few places, chiefly near 

 the junction with the newer formations, with but .'lender 

 prospect of a successful issue. 



By reference to the Custom House returns of exports I find 

 that tlie amount and value of copper ore shipped at St. John's 

 between the years 1854 and 1864 inclusive was as follows: — 

 Ore, 627^ tons, value §22,980 = 4,596/. sterling. The places 

 where this ore was raised arc not specified, but I believe it was 

 all derived from rocks of intermediate age, by which the greater 

 part of the Peninsula of Avalon is occupied. 



In addition to the above export from St. John's, 544 tons, 

 valued at Sl9,l79were exported between the years 1875 and 

 1879 ; but a considerable, if not the larger portion of this ore 

 was produced from Tilt Cove and other of the early openings in 

 Notre Dame Bay. 



Although the presence of copper is frequently indicated by 

 stains of green carbonate and small nests of yellow sulphuret in 

 the lo«er Primordial strata, I am not aware of any instances 

 where the ores occur in mass, or in intersecting veins or lodes, 

 except it may be close to their immediate junctiun with the older 

 series on which they repose unconformably or butt up against in 

 faults. At some parts of their distribution, such as in the 



i-^lands of Conception Bay, these older Silurian rocks'are but very 

 little disturbed, resting in nearly a horizontal attitude, and 

 scarcely at all altered ; at other parts, such as Trinity Bay, St. 

 M iry's Bay, LingL is Island of the Miquelons and elsewhere, 

 they are greatly disturbed by intrusions of igneous rock, and 

 occasionally to soue extent metamorphosed ; but they are almost 

 everywhere crowded with organic remains, the types of which 

 indicate the ages they represent, to extend from the horizon of 

 Primordial or Cambrian to the newer Potsdam Group of the 

 United States and Canada. Strata repre-entative of Potsdam, 

 Calciferous, and Levis ages, containing abundance of typical 

 fossils, are extensively displayed on the western and northern 

 parts of the island, tlie former in many cases resting directly on 

 l,:iurentian gneiss unconformably ; but, except it may be to a 

 very limited extent in Canada Bay, near the Cloud Mountains, 

 1 am not aware of any deposits older than the Potsd.am at these 

 parts, nor have I seen indications of the presence of the Huronian 

 or intermediate system north of Bonavista Bay, or anywhere 

 near the western shores. Galena in calcareous veins is of fre- 

 quent occurrence in these Lower Silurian rocks, but except in 

 small isolated crystals or patches the ores of copper are particu- 

 larly rare, and in no case such as to be considered economically 

 valuable. 



But the cupriferous formations proper of Newfoundland, 

 acco'ding to my view of the structure, lie unconformably above 

 all the former, and consist mainly of a set of metamorphic and 

 igneous rocks, corresponding exactly in mineral character and 

 condition with the rocks of the Eastern Townships of Canada 

 described by Sir Wm. I^ogan under the title of the Quebec 

 Group. I am quite aware that these view's, as regards the struc- 

 ture, are at variance with those entertained by several dis- 

 tinguished geologists in Canada (whose opinions, however, do 

 not seem to be very unanimous on the subject) ; and there can- 

 not be a doubt that in many cases the evidences appear to be so 

 contradictoi7 at different localities that the difficulties in arriving 

 at the truth are exceedingly great. Nevertheless, so far as my 

 own observations go, and I have studied the succession at nearly 

 all parts of their distribution in Newfoundland, I am led to the 

 conclusion that the stratigraphical position of this metamorphic 

 group belongs to a horizon intermediate between the Calciferous 

 and Hudson River group, probably chiefly of Chazy age, which 

 is in accord with the structure of Sir W. E. Logan. 



The group consists of chloritic, dioritic, and felsite slates, 

 interstratified with compact diorites, bands of rel jasper, dolo- 

 mites, great masses of serpentine, or serpentinous rock, and vol- 

 canic products. In nearly all these rocks the ores of copper are 

 more or less disseminated ; but it is amongst the schistose portions, 

 especially the clorite slates, that they seem to be most abundant, 

 and it is in rocks of that quality chiefly where the principal 

 mining operations have hitherto been conducted. At some parts 

 of the distribution these rocks are distinctly stratified, the lines 

 of deposit being well displ.ayed in layers of different quality : 

 beds of jasper, conglomerate, &c. The whole series is magne- 

 sian, more or less, but particularly towards the top, which 

 appears to be the horizon of the serpentinous masses, with hitge 

 accumulations of volcanic ash. Towards t'ae base the rocks 

 become calcareous, the cliffs of strata much incrusted with car- 

 bonate of lime ; and some strata of a pure white crystalline 

 limestone occur which are fossiliferous. The fossils are too 

 obscure to be identified vpith certainty ; but one form bears a 

 strong resemblance to a Maclurea, another to a Bdlerophon, a 

 third to a Murchisonia, and some ratlier large-sized Encrinite 

 stems. Near tlie horizon of this lime-tone moreover we find a 

 set of black slates which contain graptolites. Vast intrusive 

 masses of granitoid rock, and great dykes of greenstone 

 melaphyre and other traps intersect the formation. 



The only mines of importance in active operation up to the 

 present time are all situated in Notre Dame Bay, and these are 

 Union Mine Tilt Cove, Betts Cove Mine, Colchester, in south- 

 west arm of Green Bay, Little Bay Mine, Rabbit's Arm, and 

 Seal Bay. Many openings and minor workings have also been 

 made at various parts of the bay, at each of which the ores of 

 copper were more or less indicated, some of which may eventu- 

 ally, when capital and skilled labour are brought to bear, be 

 found sufficiently remunerative to be worked to advantage. 



It w ill be seen by the annexed memoranda that the total value 

 of the copper and nickel ore extracted since 1S54, but by far the 

 larger proportion since 1S64, when the Union Mine Tilt Cove 

 was first opened by Mr. Smith McKay, amounts to nearly cue 

 million sterling. 



