LAURENS 



3345 



LAURENTIAN PLATEAU 



An $85,000 post office was in course of erection 

 in 1916. In the vicinity is the state agricul- 

 tural farm. 



LAURENS, law'renz, HENRY (1724-1792), 

 an American statesman of the Revolutionary 

 period. He was born at Charleston, S. C., and 

 early became a conspicuous figure in the pa- 

 triotic group which opposed British aggression, 

 being one of thirty-eight Americans who signed 

 a petition to dissuade Parliament from pass- 

 ing the Boston Port Bill (1774). In 1775 he 

 became a member of the First Provincial Con- 

 gress and was elected president of the Conti- 

 nental Congress in 1777. Laurens was sent to 

 Holland in 1779 to negotiate a commercial 

 treaty, but was captured at sea by the British 

 and imprisoned in London Tower for fifteen 

 months. Twice he refused offers of pardon, 

 for each time it was made a condition that 

 he serve the British ministers. In 1782, with 

 Adams, Jay and Franklin, he signed the pre- 

 liminary articles of peace between the United 

 States and Great Britain ( 1782), ^ but failing 

 health prevented his remaining in Paris for the 

 negotiation of the final treaty. 



LAURENTIAN, lawren' shian, PLATEAU, 

 or LAURENTIAN SHIELD, a vast region in 

 North America, comprising more than one- 

 half of the total area of Canada. It is shaped 

 roughly like a shield surrounding Hudson Bay 

 on the east, south and west, and forming a 

 large part of the great islands to the north. 

 On the east it forms the Labrador peninsula. 

 On the south it extends through the province 

 of Ontario as far as Lake Superior and Geor- 

 gian Bay. West of Hudson Bay the shield 

 spreads to the northwest, its western edge be- 

 ing not far from and parallel to the Mackenzie 

 River. The highlands of the part of the shield 

 lying in Quebec north of the Saint Lawrence 

 River are frequently called the Laurentian 

 Mountains, but of mountains in the usual sense 

 of the word there are none. 



Surface and Drainage. The physical features 

 of the shield are nearly uniform throughout its 

 2,000,000 square miles of area. Its average 

 elevation is about 1,500 feet, but it is highest 

 towards the margin and dips gently down to 

 sea level around Hudson Bay. Along the east- 

 ern border, on the coast of Labrador, are the 

 highest levels, rising in the Nachvak Moun- 

 tains to an altitude of 5,000 or 6,000 feet. The 

 surface is hilly, or hummocky, for the harder 

 rocks, such as granite, stand out as rounded 

 knobs or narrow ridges. Viewed from the val- 

 ley of the Saint Lawrence the effect is that of 

 210 



mountains, but an observer stationed on one 

 of the higher hills can see that the region was 

 once a plain, for all the hills rise to about 

 the same level and form a uniform skyline. 



The most characteristic feature of the region 

 is the innumerable lakes, of all sizes, with 

 which it is covered. These lakes and the wind- 

 ing rivers flowing in all directions form so 

 nearly continuous a series of waterways that 

 it is possible, by making occasional portages, 

 to travel in any direction in a canoe. The 

 winding courses of the rivers, flowing from al- 

 most every lake, are due largely to the pres- 

 ence of soft rocks in company with granite 

 and other hard rocks. The larger lake basins 

 have been formed partly by the removal of 

 the softer rocks, but mainly by the damming 

 of valleys through glacial deposits. The riv- 

 ers generally have no regular channels, but 

 spill over from one basin into the next, though 

 a few of them cross the edge of the shield and 

 flow in very deep, high-walled valleys cut in 

 solid rock. The most famous of these, the 

 Saguenay and Hamilton rivers, flow between 

 walls 1,500 to 1,800 feet high, and end in long 

 valleys floored by the sea. They are good ex- 

 amples of fiords, comparable to those of Nor- 

 way. 



The watershed between the Hudson Bay 

 rivers on the one side and the Great Lakes- 

 Saint Lawrence system and the Mackenzie 

 system on the other is very irregular and often 

 low and marshy without any continuous range 

 of hills or mountains. There are lakes on the 

 divide which send part of their waters to the 

 Great Lakes and part to Hudson Bay. 



Soil and Vegetation. On the ridges the soil 

 is generally thin, but in the valleys it is often 

 very rich and productive. The southern part 

 of the Laurentian region includes immense 

 stretches of forest land, which are, with the 

 possible exception of British Columbia's for- 

 ests, the Dominion's chief source for timber. 

 In the far north, on both sides of Hudson Bay, 

 are the barren lands, hills and valleys on which 

 grow only grasses, mosses and lichens. Gold, 

 silver, nickel, copper and iron are mined in 

 various sections, and fur-bearing animals are 

 common nearly everywhere. 



Oldest Part of North America. When the 

 wrinkling of the earth's crust first caused the 

 land to rise above the water, the first part of 

 North America to appear was the Laurentian 

 shield. This was followed by the Appalachian 

 system, and later by the Rocky Mountains 

 system. Between these three mountain masses 



