TVALcoiT.J ATLANTIC COAST KESUME. 273 



tbat in their country, the Paradoxides zone occupied a superior position 

 to the Olenellus zone. With the knowledge we now have of the strati- 

 graphic succession of the Cambrian faunas, the Paradoxides beds of 

 Braintree are considered to be superior to the Lower Cambrian rocks 

 of Attleborough. 



RESUME. 



The physical characters and condition of the rocks constituting the 

 formations referred to the Cambrian in this province indicate that they 

 were accumulated not far from the shore line, and th at several fluctua- 

 tions in the level of the sea bed occurred during Cambrian time. On 

 the coast of Labrador the accumulation of sand was followed by a 

 deepening of the sea and the deposition of calcareous mud. That the 

 depth was not profound, is shown by the character of the limestone and 

 its fauna, and the preseuce of lenticular masses of red and green shale. 

 The 231 feet of sandstone, and 140 feet of limestone in the section rep- 

 resent only a portion of the Lower Cambrian or Olenellus zone. Two 

 hundred miles to the soutu, on the west coast of Newfoundland the 

 preseuce of 605 teet of slate beneath the alternating series of limestone 

 and quartzite, over 1,000 feet in thickness, tell the same story of rela- 

 tively shallow water accumulation. 



On the Atlantic coast side, at Canada Bay, there are 2,500 feet of 

 slate, conglomerate and eruptive rock, subjacent to a series of lime- 

 stones and slates nearly 3,000 feet in thickness. There is here a greater 

 development of limestone than anywhere to the south along the At- 

 lantic coast line. It appears to have accumulated upon the bed of a 

 protected sea not far distant from the shore and to have been frequently 

 interrupted in deposition by the throwing down of a considerable thick- 

 ness of argillaceous mud. 



In southeastern Newfoundland the assembled sections have, accord- 

 ing to Messrs. Murray and Howley, a thickness of nearly 6,000 feet, of 

 which 128 feet are limestone, and the remaining portion argillaceous 

 and arenaceous deposits. In the section on Manuel's Brook a conglom- 

 erate rests upon the pre-Cambrian gneiss, and upon the upper bed an 

 irregular, arenaceous limestone in which layers of more or less pure 

 limestone occur. This limestone-forming epoch was of very short dura- 

 tion, and was succeeded by an accumulation of clay that now forms a 

 series of shales nearly 1,000 feet in thickness before sandy layers ap- 

 pear. When once the sandstones begin to alternate with the shales, 

 they continue on up to the summit of the group and are very abundant 

 in the Upper Cambrian. The sediments of southeastern Newfoundland 

 were accumulated in bays of the pre-Cambrian sea and derived almost 

 entirely from the adjacent shore, either as sand and silt, worn from the 

 rocks by the sea, or brought down to it by tributary streams. 



The 4,000 feet or more of rocks in the New Brunswick section are 

 almost entirely shales with a few sandstones and basal conglomerates. 

 Bull. 81 18 



