42 ESKAR EXCAVATION IN NOVA SCOTIA. PREST. 



information conveyed by this clay bed will be referred to 



later on. Then came a slight change in condi- 



HkjIi level tions and a stronger current covered the clay 



deposition with sand. (Bed No. 11). Then came a period 



of erosion which cut away both sides of all the 



beds from No. G to No. 10. This was caused either by the 



removal of a debris dam or by an increase of temperature and 



a more rapid melting of the ice and a consequent increase in 



the flow of water. 



One result of this erosion was that the southern side of 



the eskar is the most steeply eroded, while the northern slope 



is broader and less steep. These facts tell a tale 



An of great import. Nearly all of us have noticed 



^'eJidenc'c ^^ ice-filled road drains, how a crack becomes a 



watercoupee which fills with earth as the crack 



grows larger. If the crack ran north and south nothing 



worthy of note happened. But if it ran east and west the 



north side received more sunlight than the south side. And 



as the north side melted faster, the debris spread out on that 



side while lying higher and closer to the south or shady wall. 



The Middlefield eskar tells us the same tale. A tale of a 



time when high ice walls enclosed and overhung the debris 



there and the slanting southern sunlight shone 



The only only On the northern w^all. The south wall, 



solutiuH always in the shadow, could melt but slowly, 



and the debris lying against it was eroded but 



little, long retaining its steep face. The north wall of the 



crevasse receding faster, gave more room for the eroded 



material, hence the gentle slope. Nature's records here seem 



to be clear and easily read. The relative slopes of the sides 



of an east and west eskar are important evidences of origin, 



and I much desire such information from other investigators. 



I must say here that while evidences of such erosion are 



noticeable on the lower layers they are not so prominent as 



on the beds numbered from 6 to 11. 



This erosion was the beginning of new conditions brot 

 on by increasing waterflow. the result probably of increasing 

 temperature. Strong currents covered the lower 

 Agreement beds with unconformable layers of generally 

 improvement coarse but Variable character. Large rocks alter- 

 nate with small rocks, gravel and sand. The upper 



