234 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



hornblende gneiss with abundant lenses of segregated hornblende and 

 biotite. The strike varies from X. 15° W. to N. 30° W., and averages 

 N. 25° W. From its trend, the Tallek was seen to be a strike-valley. 

 The same may be said of the valley of the Kogarsuk, which mouths 

 just west <>f Kipsimarvik. At the Post, thin sheets or dikes of eruptive 

 rock cut the gneiss. They are light purplish-gray in color, and recall 

 the anorthosites of the south. Gneiss similar to that at Kipsimarvik 

 composes the northern and western slopes of the Kutyautak. 



At the head of the Tessyuyak, the variegated cliffs proved to be in 

 largest part made up of badly weathered ferruginous and silicious schists, 

 graphite gneiss, and graphite schist. With these was associated in con- 

 siderable development a peculiar breccia of angular quartz fragments em- 

 bedded in a black corneous matrix. The graphite occurs abundantly in 

 the form of disseminated flakes. No large mass of the pure mineral was 

 discovered in the short time at our disposal. That such a discovery is 

 possible appears from the fact that a rounded piece of pure graphite 

 measuring four by five inches has been found at the foot of the talus 

 near the great alluvial fan ; it is now in the possession of Mr. Ford. 



The General Structure of the Coastal Belt. 



From the foregoing account, it may be seen that, in the line of the long 

 coastal section from Belle Isle Strait to Nachvak, Labrador is underlain 

 by the crystalline complex. If, now, a review is made of the most 

 important structural element, strike-direction, one cannot but conclude 

 that the Archaean shield is rather definitely framed on this border, and 

 that the average direction of the coast-line is related to the tectonic 

 trend of the ancient mountain-system of which the Labrador plateau is 

 a diminished remnant. (Plate 11, Table I.). A similar parallelism of 

 structural trend and coast-line probably exists along the high mountain- 

 belt of eastern Baffin Land as far as Lancaster Sound. 1 It should be 

 stated that the brief table and the map do not represent the only evi- 

 dence for this law as expressed in Labrador. Very often the general 

 attitude of the crystalline schists could be determined from the schooner 

 when under way, although no opportunity could then present itself for 

 accurate measurement of the strike. The impression thus gained is 

 sufficient to warrant our regarding the fidelity of the structure to a 

 general X. \V.-S. E. trend as of a higher order than is shown in the table 

 or in the sketch-map. On the other hand, it is evident that no record 



i E. Suess, La Face de la Terre, 1900, vol. 2, p. 47. 



