1 00 On the Transition Rocks of the Cataraqui. 



No rocks analagous to the granular talcose limestone, mica slate, 

 and graywacke with the anthracite group, are observable nearer than 

 Gananoqui, or about seventeen miles below Kingston, which we have 

 as yet had no opportunity of personally examining,* but from various 

 descriptions and the possession of large and numerous specimens, we 

 entertain no doubt that there are vast associations of serpentine, steatite 

 of many varieties, talcose minerals, and a highly crystalline and very 

 brilliant white saccharoid marble, which, with the rough and singular 

 scenery, so opposed to the tranquil plain plateaux of the adjacent 

 country to the westward, prove, that this class of transition rocks ex- 

 ists there, or else that they are merged into the primary order, wherein 

 an extensive deposit of magnetic iron appears, which has hitherto 

 been very imperfectly explored. f 



In an essay like the present, a few passages only can be spared 

 for the details of those systems of the transition formations which do 

 not bear an immediate or close connection with the rocks of the Cat- 

 araqui, nor should we mention them at all, but that it is useful to col- 

 lect as many data as possible on so very interesting a subject. 



Of the porphyries and sienites immediately covering primitive rocks 

 with black limestone and greenstone, it would at a first glance appear, 

 that we have at Kingston ample materials on which to expatiate ; but 

 this division of transition rocks, abounding in hornblende almost desti- 

 tute of quartz ; non-metalliferous ; reposing immediately on the primi- 

 tive genera, and sustaining nearly the same relations, seems exceed- 

 ingly difficult to separate from the class posterior to clay slate and 

 which is metalliferous. The latter is said, but without sufficient proof, 

 to be a later formation than clay slate, whilst the former is anterior to 

 that rock, a position which all the learning and elaborate research of 

 Humboldt and of the German school fail to substantiate, nor from 

 the total absence of clay slate in the Cataraqui locality, could any 

 data to prove it, be in the present case, adduced. 



We shall therefore blend these two classes together, and go on ex- 

 emplifying it by detailing at large the facts as they occur, adding re- 

 marks afterwards on the transition euphotides witli serpentine, and 



* " On voit a Gananoqui quelques especes de steatite done on assure qu'il y a des 

 larges veines dans le voisinage." — Guillemard. 



t I am not, however, aware, whether or no anthracite has been found near Gan- 

 anoqui, although it appears probable that this substance will be obtained in some of 

 the formations between Kingston and that place. It bears, according to Humboldt, 

 the same relation to the transition rocks, as graphite does to the primitive. 



