[MATTHEW] STUDIES ON CAMBRIAN FAUNAS 167 



matrix tor the fossils, and helps to indicate that in the sediments imme- 

 diately adjoining the quartz-diorite we have those of an ancient shore 

 line of Cambrian age. Studies of the Cambrian sediments of central and 

 northern Sweden made by J. G. Anderson and H. Iledstrom, lead us to 

 suppose that the presence of calcium-phosphate in rocks indicates shallow 

 water or a shore line. The former found it in association with glauconite. 

 and always with a fauna such as woiild exist in a shallow sea ; and the 

 latter contends that this mineral is deposited either on the land or on the 

 immediate shore line, being there often the result of submerged deposits 

 made on the land. Whichever view we adopt the presence of phosphates 

 in sediments indicates shallow water. 



On the shore of the Kennebecasis, where these fossils are found in 

 the Cambrian measures, there is no trace of the lowest portion of the 

 Cambrian system, namely, the basal quartzites, the sandstones and shales 

 containing the Protolenus Fauna and the shales containing three sub- 

 faunas of Paradoxides, and as the Cambrian sediments here begin with 

 a sandstone containing a Paradoxides Fauna, it would seem that the 

 other beds never were deposited on this ridge. 



The measures actually present consist of about 20 feet in thickness 

 of greenish-gray sandstones next the quartz-diorite, about 10 feet of gray 

 shale, and about the same thickness of black shale. Any higher meas- 

 ures which may be present are concealed beneath the waters of the cove. 

 Both the sandstones and the gra}' shale weather to a rusty brown colour 

 from the presence of disseminated p3n'ites. The u})per part of the sand- 

 stone antl the whole thickness of the gray shales contain thin, irregular 

 beds and lentiles of limestone, and calcareous conglomerate, containing 

 fragments of the Laurentian quartz-diorite and limestone, as mentioned 

 above. 



Sandy layers are also found in the lower beds of the black shales» 

 most of which have abundant fragments of minute trilobites. The 

 black shale itself is mostly quite siliceous, and breaks into cubical pieces, 

 so that it is difficult to get recognizable portions of the larger trilobites 

 from it. 



We suppose these measures to be eqviivalent to certain barren dark 

 gray shales, which often have thin sandy seams, and which in the St. 

 John Basin of Cambrian rocks lie above the beds of Division 1, which 

 have been found fossiliferous. While, thei-efore, the}- belong to Division 

 1 by their fauna, the}- are above that part of the division which has 

 been found fossiliferous in the more southerly basin. 



Were we to depend upon lithological resemblances we would come 

 to a different conclusion, for comparing the sedimentation along the 

 Kennebecasis with that of the St. John Basin, the sandstones at the 

 base compare with Division 16, which carries the Protolenus Fauna ; the 

 gray shales, with Division Ic, which contains the two sub-faunas of 



