1-78 Dr. Berger 071 the Geological Features 



The following simple minerals occur imbedded in the rocks of 

 this series ; they are enumerated in the order of their more frequent 

 occurrence. 



1. Granular olivine. 5. Zeolite, comprizing analcime, 



mesotype, stilbite & chabasite. 



2. Augite. 6. Iron pyrites. 



3. Calcareous spar. 7. Glassy felspar. 



4. Steatite. 8. Chalcedony; passing sometimes 



into semi-opal. 



Granular olivine in disseminated grains seldom fails in the tabular 

 basalt ; and sometimes occurs also in greystone. It has a remarkable 

 mode of decay, becoming tender, and iridescent. 



Augite usually accompanies greenstone and sometimes greystone. 

 Steatite is almost exclusively limited to the prismatic basalt ; and it 

 is likewise the only heterogeneous ingredient I have observed in it. 

 It exists in small round specks, of a bottle-green colour so dark, that 

 it is not easily discernible from the mass itself: it has a dull and 

 waxy appearance ; is soft, the streak greyish. 



Glassy felspar characterizes the clinkstone porphyry. Calcareous 

 spar, zeolite, iron pyrites, and chalcedony usually occur in asso- 

 ciation with the preceding substances. 



Since the flcetz trap forms the superficial rock of the area we are 

 now to describe, it may be proper to insert in this place a list of the 

 most remarkable hills by which that surface is diversified, and some 

 other remarks on its general forms. In the list of hills, the same 

 order will be followed as before in tracing the chalk, beginning with 

 the south-east angle and ending with the south-west. The thickness 

 of the trap formation where it has been observed will be added. 



