BISTmBUTlON BRITISH AMERICA 611 



glass basis, with pseudomorphs after aiigite and olivine. The glass coat- 

 ing contains fresh olivine and feldspar, but augite is lacking. 



BRITISH AMERICA 



Newfoundland. — Daly^^ has described the variolitic pillow basalts of 

 extreme northern Newfoundland, where they constitute flows 60 meters 

 thick made up of round, smooth, bale-like and pillow-like ellipsoidal 

 masses which are discontinuous and, as a rule, perfectly individualized. 

 The whole rests on solid basalt about 1 meter thick. The masses range 

 in size from 5 centimeters to 2 meters or more in maximum diameter, 

 and the interstices between are filled with coarsely crystallized calcite, 

 quartz, and dark cherty masses. Numerous radial cracks in the pillows 

 are filled chiefly with calcite and a little quartz. These cracks are com- 

 monly widest and most numerous at the center, recalling the gaping 

 cracks of many septaria, and are attributed to contraction while cooling. 

 The rock is highly vesicular, the masses are slightly indented at their 

 points of contact with each other, and the larger ones are flattened paral- 

 lel to the dip of the accompanying strata. "In some cases the surfaces 

 of single pillows, weathered out from their calcite matrix, were seen to 

 have the exact appearance of ropy lava." The varioles tend to a con- 

 centric arrangement and increase in both size and abundance toward the 

 center of the masses. 



Daly finds the "detailed surface of pillow lavas more like that pre- 

 served by pahoehoe than like the ragged surface of aa blocks," and he 

 concludes that their origin is due to "extrusion of basic lava into sea- 

 water of some depth." 



Neiu Brunswick.- — Ells^^ described doleritic rocks from northern New 

 Brunswick with a "concretionary structure," the "concretions" varying 

 in size from 6 inches to several feet in diameter, and on broken surfaces 

 disclosing a circle of small holes in dots around the outer margin. 



Ontario. — In the greenstones of the Lake of the Woods region Law- 

 son^* found a structure, "apparently concretionary" and closely resem- 

 bling in appearance the associated lenticular agglomerates, and the rock 

 of which is similar to the greenstone schist that constitutes the paste of 

 the agglomerates. 



"This structure consists in the rock being divided into more or less irregular 

 spherical or ovoid masses varying in diameter from 2 or 3 inches to as many 



82 R. A. Daly : Variolitic pillow lava from Newfoundland. Am. Geol., vol. xxxii, 1903, 

 pp. 65-78. 



«3 R. W. Ells : Report on the geology of northern New Brunswick. Geol. and Nat. 

 Hist. Survey of Canada, 1881, p. 24D. 



" A. C. Lawson : Report on the geology of the Lake of the Woods region. Geol. and 

 Nat. Hist. Survey of Canada, 1885, pp. 51.53CC. 



