208 F. B. TAYLOR ORIGIN OF THE EARTH's PLAN 



they did not move as far as did Labrador and the main body of the conti- 

 nent. The relation of the coast of Labrador to the west coast of the 

 south part of Greenland is truly remarkable. This is shown by the lines 

 LL, MM, NK, and 00. These lines are parallel with the lines DD and 

 FF on Baffin Ba}^, but they are considerably longer, being each about 560 

 miles. Thus for a distance of about 450 miles the two shores of the 

 Labrador Sea, although now 560 miles apart in the direction of the rift 

 along the northwest side of Greenland, are almost exactly parallel and 

 the geological age and structure of the rocks, so far as known, are the 

 same. If the crust pulled away evenly, as these facts suggest, one would 

 expect Grant Land and Baffin Land to be separated from the main body 

 of the continent by other narrower rifts. Such rifts may be represented 

 by the long, straight channel of Lancaster Sound, Barrow Strait, Mel- 

 ville Sound, and Banks Strait. A longer, less continuous passage, proba- 

 bly representing a wider rift, follows Hudson Strait, Fox Channel, Gulf 

 of Boothia, and McClintock Channel. 



We seem to have here a great irregular rift line along which ^N'orth 

 America has been torn away from Greenland. One part, extending alone 

 the northwest coast of Greenland, is a longitudinal rift, a great fault line 

 with horizontal offsetting displacement. The other part, comprising 

 Baffin Bay, Davis Strait, and the Labrador Sea, is a transverse rift along 

 which one side was pulled horizontally away from the other. The two 

 together are over 2,500 miles long. Then there are also the lesser trans- 

 verse rifts mentioned above. 



Perhaps no one of these measurements or relations taken by itself is 

 of much value, but the assembled group makes a strong case for the pull- 

 ing away of North America from Greenland. The Labrador coast is high 

 and bold, and the Greenland coast facing it is moderately so. Both 

 coasts have deep water close off shore. The parting of these shores can 

 hardly be more recent than the Tertiary, nor is it easy to believe that it 

 is much older. Even if it was so recent as the Tertiary, it is quite sur- 

 prising to find the opposite walls of a rift 450 miles long pulled 560 miles 

 apart, and still remaining so strikingly parallel ; and this, in spite of all 

 the elements of irregularity which might be expected in such a move- 

 ment, in spite of the largely accidental relation of the sea surface to the 

 rift walls, and in spite of all the erosion that has taken place since. It 

 seems altogether incredible that such characters should have been pre- 

 served from times much older than the Tertians Labrador is solidly 

 intact with the main body of the continent, and the rift of the Labrador 

 Sea may therefore be taken tentatively as an approximate measure of the 

 distance of the horizontal crustal movement of North Amrica in the 

 Tertiary diastrophisni. 



