80 Essay on the Transition Rocks of the Cataraqui. 



an almost continuous line along its centre, which have a very curious 

 appearance, but proceed from the wasting away of a layer of amor- 

 phous crystals of carbonate of lime, which as they are generally ei- 

 ther egg shaped or rounded exteriorly, may have proceeded from a 

 deposite of testaceous remains. 



Above the iron brown band is another much more inclining to 

 white, which is again followed by a bed approaching to a bluish green, 

 and upon that bed a thick brownish and very fissile layer is superim- 

 posed, which is capped by debris and soil from the hill above. 



The hill now dips towards the lake, and the connection of this 

 sandstone with the usual limestone of the locality is lost, and pro- 

 ceeding along the shores covered with numerous boulders of foreign 

 rocks, we arrive, in a short transit, at a spot where the bank, again 

 rising, shews more indications of the soft stone. 



Here a struggle betv/een lime and silica appears to have occurred, 

 for the silicous particles have disappeared in a layer composed of 

 calcareous tufa, which is visible for some feet, and being loosely co- 

 herent -is easily extracted. It lies above the hard rock, and proba- 

 bly between it and the soft, which gives indications of terminating 

 its course here. The specific gravity of this tufaceous bed is the 

 same as that of the adjacent sandstone, 2.6. 



The shores of the lake now become covered with boulders in 

 which feldspar chiefly predominates, and from their size and number, 

 they hinder the observer both in his progress and examinations. The 

 limestone beds occasionally, however, present their bassets towards 

 Haldimand cove, whereby may be traced the usual uniformity of 

 their deposition, and it may not be uninteresting to the geologist to 

 give an accurate section of those beds which have here been denu- 

 ded in cutting for a well, and in which the almost regular alternation 

 of layers of only a few inches in thickness at every third or fourth 

 stratum of beds generally exceeding a foot, is very remarkable. 

 Could these deposits have been regulated by the comparative ab- 

 sence or presence of the solvent, which in the ancient seas, caused 

 the precipitation of the lime from the fluid, or were these regular 

 formations of almost primitive matter, caused to vary in their quan- 

 tum by being precipitated at long intervals, which is indeed the most 

 probable, or how can we otherwise account for their regular stratifi- 

 cation and the usual accompaniments of roughened surfaces which 

 generally are coated with a thin white or black layer. The lower 

 bed must in short, have been always hardened, before the upper one 



