68 AN ABANDONED MARINE SAND-BAR 



would have upon this part of the countiy. These strong tides, 

 sweeping down and up the valley, over the material of the 

 sea floor, would scour up loose sand and heap it in bars of 

 various shapes. 



The material of this bar consists of quartz sand, with 

 small pebbles of ])luish slate, quartz, trap, etc., all more or 

 less abraded or semi-rounded. The slate was probably 

 derived from the rocks of the Gold Measures or of the Devon- 

 ian or Silurian formation, which lie to the south, and the 

 trap from the Triassic igneous rocks of the North Mountain. 

 Very likely the material is glacial drift worked over by the 

 sea. 



Upon the rc-elevation of the country, the denuding 

 agencies of the atmosphere would probably alter the sand- 

 bar's original form somewhat, and would mould it into its 

 present shape. 



This interpretation may be erroneous, Init it seems to 

 be in harmony with the few facts that have been given me 

 and with the scanty evidence I have been able to gather. 



Supplementary Notes. 



In my paper which I submitted to the society on May 

 10th of this year, I claimed that the mound of sand near 

 Coldbrook was an abandoned marine sand-bar. Since then 

 I have collected stronger evidence to support my claim. 



During the early part of the summer of 1920, I spent 

 part of a daj' in Woodside, Kings Co. The peculiar shape of 

 a number of small hills and hummocks immediately drew my 

 attention, and I investigated them. 



Some of these mounds of sand are about 1,000 feet 

 long, and 200 to 300 feet wide, but I do not think that any 

 of them exceed 20 or 25 feet in height. They nearly all stand 

 a little above the level of the surrounding country, which is 

 a gentle undulating plain. 



Generally speaking, the direction of their longer axis 

 is east and west. This fact is certainly fatal to the drumlin 



