386 HO-NEYMAN ON NOVA SCOTIAN GEOLOGY. 



the limestone formerly used. Besides being a flux it adds 25 per 

 cent, of iron, the iron thus produced is adapted for chilling. 



The extension of these strata, east and west, contains the depo- 

 sits of limonite. The largest deposits lie to the west of the ankerite. 

 In the same band there occurs a red hematite, which is used with 

 the limonite and ankerite. These deposits all appear to be in th3 

 upper part of the band, and are probably of Upper Silurian age. 

 The greatest width of the band is in the region of the red hematite, 

 There it seems to be about a mile in width. Succeeding this band 

 is the carboniferous of the Intercolonial Railway. The slate« of 

 the ankerite are overlaid by lower carboniferous conglomerate, 

 those of the red hematite by lower carboniferous limestone. This 

 difference of rock seems to account for the difference in width of the 

 Silurian band in the -bS localities, as conglomerate forming con- 

 ditions are destructive, and limestone forming conditions conserva- 

 tive ; the one being formed from the tear and wear of rocks on the 

 shore, the other being formed in the depths by marine lime-forming 

 invertebrates. This conglomerate and limestone may therefore be 

 regarded as cotemporaneous. It is not unusual to find lower 

 carboniferous limestones lying directly on pre-carboniferous rocks. 

 The Pictou Coal Field furnishes many examples.— F^cZe Transac- 

 tures, 1870 — 1-2 Papers, by the author. 



Following the course of Great Village River, from the London- 

 derry Iron Works, we have a fine section of this carboniferous 

 band, more distinct even than that of the Intercolonial Railway. 

 In this, about three miles from the iron works, we have a quarry 

 which once was the haunt of reptiles of the middle carboniferous 

 period. Dendrerpeton acadianuni, Owen, or his congeners. 

 From this locality there is a sandstone slab in the Museum, which 

 has three fine setts of casts of right and left reptilian tracks, one 

 sett traversing it longitudinally and the others crossing and recross- 

 ing nearly at right angles. We have thus met with reptiles on 

 either side of the Cobequid Mountains, of the same period, but in 

 different geological horizens, the one being of the lower and the 

 other of the middle carboniferous formation. Not far from the quar- 

 ry we have the commencement of the new red sandstone, permian 

 and trianic. This is also well exposed on either side of the river as 



