Page:Transactions of the Geological Society, 1st series, vol. 3.djvu/419

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its northern extremity, which declines as it stretches towards Manresa. This chain consists of similar materials to Montserrat; viz. of vast beds of farcilite, composed of rounded masses of quartz, with angular pieces of siliceous slate, and fragments of clay slate united by a basis containing calcareous earth. The fragments of this farcilite become smaller as we go northward, and at last bear t striking resemblance to coarse greywacké; to which formation I am inclined to assign the pudding stone of Montserrat, and the chain of which it forms a part.[1]

On descending the rugged mountains of pudding stone into the valley of the Lobregat, before coming to Manresa, we observe strata of a bluish grey rock with interposed layers of a softer material of the same colour, which crumbles into sandy clay by exposure to the weather. Those strata have some resemblance to sandstone-flag; but an attentive consideration convinced me that they ought to be considered. as stratified greywacké approaching to greywacké slate. Above these we again find the farcilite, which is the prevailing rock about Manresa. All the rocks hitherto mentioned effervesce slightly with acids; a circumstance which connects them in some measure with the extensive limestone country to the south-west of Montserrat; and they all shew a tendency to split vertically into columnar masses. Beyond Manresa the farcilite occurs till the traveller crosses the ford of the Cardonero, when it is succeeded by s limestone of a dirty iron brown colour, and dull, almost earthy, fracture. Beyond

  1. It may not be improper here to remark, that the common descriptions of Montserrat, are in several respects erroneous. It is not an insulated mountain, as generally represented; but is the highest point of a considerable chain. Its insular appearance, as seen from the high road between Igualada and Martorel, has deceived those who have never examined its north-eastern side. The touchstone, mentioned by Bowles and others, as entering into the composition of its pudding stone, appears by its fracture to he only a dark coloured common siliceous slate.