.?! 



102 J. E. WOODMAN PROBABLE AGE OF THE MEGUMA SERIES 



tween the two formations, graphite occurs in seams up to 3 inches in 

 thickness parallel with the stratification. In neither formation is it char- 

 acteristic of any definite horizon. 



It appears, then, that graphite is useful in the present connection only 

 as showing an abundance of life in some small form or forms, di'trihutert 

 throxighout the time occupied by the deposition of that part of the series 

 now open to view, and entombed in its argillaceous sediments, chiefly in 

 the upper formation. 



LIME "^i 



There is little limestone in the Meguma. Faribault mentions one 

 horizon. At the contact between the two formations lenticular bodies . 

 can be traced intermittently from the western side of Halifax harbor east- 

 ward for many miles. This is the onl)'' horizon known and is thorough]'/ 

 crystalline. 



There is a large amount of calcite in the quartzites as cement — an 

 amount great enough to offer some difficulty of explanation. The quartz- 

 ites are often feldspathic; but the feldspar is chieflj' orthoclase, and 

 plagioclases and basic lime-bearing silicates show no evidence of having 

 been abundant in the rocks from which the quartzites were formed. 

 Indeed, the general constitution of the latter requires acid progenitors. 

 A more probable origin for this lime would be as a deposit of fine calca- 

 reous detritus from invertebrates mingled with a preponderating volume 

 of sand and later turned into secondary interstitial calcite. But in any 

 case it has no definite value in the age problem. 



HISTORY OF RECORDED "FOSSILS" 



The record of "fossils" begins with the announcement by Hind already 

 mentioned. 



"At Waverley the concretionary forms vary from half an inch to 4 inches 

 in diameter. They are generally oval in shape, but sometimes round, with a 

 depression in the center. Attached to some of them are numerous arms, all 

 symmetrically arranged" (1869, page 62). 



Palseotrochus has long since been shown to be of inorganic origin. 



Of some forms found by Hind at Waverley, and presumably the same 

 as the above, Dawson (1878, pages 82-83) gave the only specific descrip- 

 tion offered for any of the "fossils" of the series and invented for them 

 the name AstropoUthon liindi. The frequency with which such words as 

 "seem" and "appear" occur in the description indicates the uncertain 

 nature of the evidence. 



The supposed land plant Eophyton, discovered by Selwyn (1872), has 



I 



