AND OBSERVATIONS. 



109 



hornblende, felspar-porphyry, containing chlorite, 

 and light green coloured steatite ; and a granular 

 rock, sometimes slaty and sometimes compact, com- 

 posed of felspar and hornblende, or small masses of 

 hornblende in a base of felspar ; with other subordi- 

 nate primitive rocks allied to these. The syenite 

 formation opposite to Bunawe, alternates with por- 

 phyry and greenstone. 



Bridge of Awe. — At the bridge of Awe, and 

 within a short distance from the mouth of the river, 

 there is felspar, both compact and amygdaloidal. 

 Here also, we observe the commencement of an un- 

 expected formation of newer rocks, belonging to the 

 floetz class ; which extend over a considerable range 

 of country, stretching southward, or south-west. Of 

 this formation, a great part consists of a species of 

 trap clay-stone, or iron- clay, as the base of the 

 rock. Below the bridge, a mass of conglomerate 

 rises up, evidently formed by the river itself, from 

 the debris of the higher rocks, at a period probably 

 not very remote. It contains rounded and angular 

 masses of quartz, clay- slate, felspar, &c. in a base of 

 trap clay-stone. Another rock, with the same kind 

 of base, is amygdaloidal, including pistacite, calc- 

 spar, and sometimes hornblende and steatite. Along 

 with these, a formation occurs of old red sandstone, 

 variously striped, spotted, and coloured : and the 

 whole form round-backed elevations, and precipi- 

 tous fronts, on the right bank of the water, below 

 the bridge. 2 



