198 The Ottawa Naturalist, [January 



lated. Two structural phases of rocks are specially important in this 

 connection, the a?itidine and the terrace. The time has come for the 

 acknowledgment of structure in reservoir gas fields even in advance of 

 measurements. The lola gas field is one of great promise. Its source 

 IS in a sandstone of the Cherokee Shales, or near the bottom of the 

 Coal Measures. It proves to be a terrace of well marked character. 

 For seven miles the top of the gas rock has an elevation of 131 feet 

 above tide, rising at no point more than 45 feet above this. At this 

 summit, the largest well of the field is located. 



One feature brought out in this paper is the great value of natural 

 gas as a fuel. Prof. Orion argues strongly in favour of legislation in 

 order to compel, if possible, the use of natural gas only as a fuel for 

 family or domestic purposes. He considers it-too valuable an element 

 altogether to be employed in the baser uses for manufactures. 



The Mica Industry of the United States, New Mexico, the 

 Rocky Mountains, and North Carolina. 



By Prof. VV. H. Holmes, presented his paper 



which gave a great deal of valuable information on the mode of 

 occurrence of this important industry. 



The Newark System in New York and New Jersey— 



By Prof. Henry B. Kiimmel, of Chicago, described 



a series of strata which are contemporaneous and probably similar in 

 origin to the so-called " New Red " and " Triassic Sandstone" of the 

 Minas Basin, Cornwallis and Annapolis valleys, and elsewhere in the 

 province of Nova Scotia and in Prince Edward Island. Even the 

 intrusive and extrusive trap sheets so characteristic of the New York 

 and New Jersey series in the Newark system also occur in Nova Scotia, 

 especially in the North Mountain region of Kings and Annapolis 

 Counties and in Cumberland and Colchester counties as well. 



The Archaean-Potsdam contact in the vicinity of Manitou, 



Colorado, 



By Prof. W. O. CROSBY, of Boston, was of special intesest to Cana- 

 dians. The peneplain mentioned by Prof. Crosby, in early times may 

 apply to the region he describes in Colorado, but not in Eastern 

 Ontario or Western Quebec, in Canida, where the underlying rocks of 

 Laurentian and Huronian age are deeply cut and furrowed to hundreds 

 of feet prior to deposition of the i-'otsdam. The question may be 

 asked : Are the so-called Potsdam rocks of Manitou truly equivalents of 

 the Potsdam of New York State and Canada ? 



H. M. Ami. 



