Mr. Bennett <?« //&<? Geology of Madeira, ■ S95 



species of the red and grey, alternating five or six times, and assuming 

 in its dislocation the form of a bow, both the lavas following in a 

 regular bend the shape of the curve. 



On the left of the stairs by which you are to descend, innumerable 

 small columns of the grey lava project from the side ; they dip N.W. 

 and their form in general is quadrangular ; but I found several of 

 them in prisms of three, five, and six sides. They are remarkably 

 small, and, as they lie in this bed, appear almost all to break off from 

 each other at five or six inches in length, and I never found them 

 exceed this size. They seem to form a dyke that cuts through the 

 horizontal beds of lava. 



At the edge of the descent there is a projection or range of basaltic 

 columns, rising like a wall, tapering to the top, and separating into 

 large quadrangular prisms. We found no black ashes in the valley 

 of the Corraly though towards the bottom there are considerable strata 

 of pumicej great masses of scoriae, and cellular lava, and lava in a state 

 of semi-vitrification ; the whole presenting evident marks of an erup- 

 tion, anterior to that which had formed these various strata of lava, 

 which are visible from the summit of the hill to the bed of the river. 



The dip of the strata is in general towards the sea. Basaltic 

 columns shoot from the side of the ordinary strata, which are inter- 

 sected by various dykes ; and one of these in particular swept across 

 both sides of the valley. There are here also rocks of about 100 

 feet in height, composed of a species of breccia. We examined one 

 near the church, at the extremity of tlie winding stair-case, forming 

 the descent into the valley, v/hich was composed of large and small 

 pieces of lava, some of them of many yards in length and depth, the 

 angles being rounded, and the whole agglutinated together by a 

 hard black earthy substance, that resisted all the force we could use to 



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