H0XEYMAX GEOLOGY OF ANTIGOXISHE COUNTY. (53 



variegated with alternating red strata, presenting a bold precipice 

 with a beautiful series of layers, having a dip 45°. 



Following these and seeming to butt against them is a wall of 

 dark red strata. The colour of these is uniform. They have a 

 southerly dip. The great change of direction shown by these is 

 doubtless the effect of the action of a mass of amygdaloid. This is 

 the first appearance of igneous rock since we left Arisaig Pier. 



The observer now can see the effect, although the cause is not 

 so strikingly apparent as it was when I became acquainted with the 

 spot about 20 years ago. This piece of rock scenery then was truly 

 magnificent. The huge rounded mass of amygdaloid extending 

 across the shore toward the sea so as to project into it at full tide, 

 while at the same time it overlapped and reposed on the wall of 

 silurian strata on the shore, covering what was then regarded as the 

 point of junction between the devonian and lower carboniferous for- 

 mations. When in 1868 I re-visited this scene of a multitude of 

 interesting associations, of much hammering, and many interesting 

 disclosures of new forms of ancient Silurian life. I must confess to 

 a feeling of sadness at the changes wrought on the scene by the 

 almost total disappearance of the great black rock with its friendly 

 shelter from the hot rays of the midsummer sun. The junction of 

 the then supposed Devonian and Lozcer Carboniferous, and sub- 

 sequently of the Upper Silurian, and supposed Lower Carbon- 

 iferous, is now completely exposed by the removal of the mass of 

 trap (amygdaloid), by the action of the tides and storms. 



Mr. Weston, of the Canadian survey, informed me last summer- 

 that he had found fossils which were not carboniferous, in the soft 

 unstratified (apparently) rocks which succeed the silurian well of 

 our section, so that the said point of junction is no longer to be 

 regarded as that of the silurian and carboniferous, but as the proba- 

 ble junction of two pre-carboniferous formations, or D and E of 

 the Upper Aiisaig series, vide sections : — 



McAra's Brook, No. 11. 

 Mc Adam's Brook, " 10. 

 Arisaig Pier, " 8. 



