DALY: GEOLOGY OF THE NORTHEAST COAST OF LABRADOR. 263 



Very rarely are the benches of great breadth or length ; nor are they 

 usually horizontal. They have been developed by rifting on gently 

 curving master-joints. They are not the continuous, horizontal terraces 

 of our text-book diagrams. The benches cannot be taken to mean so 

 many halts during the process of elevation ; but are rather determined 

 in size, form, and position by the controlling planes of jointing. 



Elevated sea-chasms, often located on trap-dikes, indent the cliffs in 

 large numbers. The great length of some of these is quite extraordinary. 

 A half mile northwest of the Mission House at Hopedale and at an alti- 

 tude of 325 feet, a chasm three hundred yards in length has been worn 

 out during submergence by waves that followed the trend of a trap dike. 

 The vast majority of the fossil chasms are similarly located on trap 

 dikes. The latter, with respect to subaerial destruction, may be hard 

 in comparison to the country-rock and project above the highest shore- 

 line as ridges ; below that line the same dikes may prove less resistant 

 to the attack of the waves than the country -rock and have thus served 

 to locate chasms. Examples occur on the shores of Aillik Bay. The 

 position of the highest shore-line is beautifully shown at the upper ter- 

 mination of a dike-chasm, still floored with rounded boulders, that forms 

 a conspicuous landmark above the anchorage at Ford Harbor. Above 

 the line, the surface of the dike is flush with the glaciated gneiss. The 

 most picturesque chasm seen during the summer is one 250 yards long, 

 75 feet deep, and 20 feet wide that was found on Long Island, at 

 American Tickle. The waves still reach nearly to the head of this chasm, 

 which is still being slowly deepened. 



The waste of the fossil cliffs is seen at the present day in the raised 

 beaches and other boulder accumulations that also represent, in part, the 

 rearranged drift that once lay scattered over the emerged zone. In 

 Newfoundland and southern Labrador, these deposits are as a rule 

 covered deeply under peat, which seems to prefer such graded slopes as 

 a place for rapid growth. The form and location of the slope was, in 

 such cases, used in connection with the natural sections of brook-beds 

 to indicate the nature of the deposit. North of Hamilton Inlet, the 

 lack of a vegetable cap has rendered the exposures extremely good and 

 the study easy and rapid. (Plate 10, a and b.) Perhaps the finest ex- 

 hibitions of the beaches were seen at Sloop Harbor (altitudes measured 

 115, 140, 160, and 215 feet), Aillik Bay, Hopedale, Pomiadluk Point 

 (at 55, 65, 230, 250, 260, 315, 320, and 335 feet), and Port Manvers. 



The development of the beaches was naturally found to be a function 

 of four conditions, the relative amount of drift on the shore, the 



