152 NEW YORK STATE MUSEUM 



Explanation of Pic d'Aurore section. This is the cHff section ex- 

 tending from southeast to northwest and facing the Mal-Baie. The 

 attempt has been made to give the strata approximately their 

 natural coloration in the morning sun, though actually the red color 

 of the summit peak is spread downward by the leaching of the 

 rains over the surface of the less brilliantly tinted strata. The 

 height of the Pic d'Aurore is about 800 feet. A part of the village 

 in the north bay of Perce is seen beyond Barre cape. The section 

 cuts the Appalachian folds of the Precarboniferous Paleozoic some- 

 what obliquely but is almost at right angles to the section on the 

 gulf front at Perce from Cape Barre south. 



The mountain in the background is the plateau or relict-mountain, 

 the Table-a-rolante, to whose type of structure reference is made 

 again in the following paper. This relict-mountain is composed of 

 red Bonaventure or post-mid-Devonic-Carbonic and sands and con- 

 glomerates lying in low waves dipping toward the north, and its 

 beds rest on the eroded folds of the Paleozoics. A moiety of these 

 horizontal Bonaventure beds makes the summit of the Pic d'Aurore 

 where they lie on a truncated anticline of the Devonic series. 



Bonaventure conglomerate. All the northwestern end of this 

 section is constituted of this formation and the strata here slope 

 evenly to the water so that the observer from the present point of 

 view looks against the up-surface of one bed or of closely successive 

 beds. This mass of the Bonaventure has obviously fallen down and 

 over from the horizontal plateau mass above, from which it has 

 been rifted. Sections across this mass at right angles to the shore 

 show it to be a mere veneer leaning against the Siluric-Ordovicic 

 beds. The angle of attitude in these Bonaventure marls and sand- 

 stones lessens toward the west, and at the end of the section at 

 Cannes-des-Roches the beds lie again in a horizontal position. The 

 rocks are mostly gray-green and mottled sandy marls, with some 

 sharply outlined beds of red sandstone and conglomerate layers, 

 and the edge of one of these, where the stratum has been broken 

 off and slipped into the sea, is shown at the right. There are also 

 some patchy layers of dark shale. 



Next follows in order of succession downward the Perce lime- 

 stone, which here makes the Trois Soeurs or the three cliffs at left 

 of the Pic d'Aurore, and whose closely infolded remnant is seen 

 at the right on the flank of the Pic. 



Below is the Pic d'Aurore series in characteristic close folds ; first, 

 the white sandstone showing in the east flank the dark band with 



