398 Mr. Bennett o« //&^ Geology of Madeira. 



by far the most compact of the red strata I met with in the island. I 

 saw this red lava also in the Island of Teneriffe, to the eastward of 

 Santa Cruz, as well as in the neighbourhood of Orotava. 



I have thus endeavoured to give you a slight sketch of that which 

 appeared to me most deserving of attention in the Island of Madeira. 

 The short stay I was able to make there prevented a more accurate 

 survey of the island ; yet I saw enough to induce me to recommend 

 a careful examination of the strata to those who may have more 

 time than I had to spare, and more knowledge to estimate the value of 

 that which was to be seen. To my mind, the most interesting^ geolo- 

 gical facts arc, 1st. The intersection of the lava by dykes at right 

 angles with the strata. 2dly, The rapid dips the strata make, parti- 

 culirly the overlaying of that of the Brasen Hcad^ to the eastward 

 of Funchal, where the blue, grey^ and red lavas are rolled up in one 

 mass, and lie in a position as if they had all slipped together from an 

 upper stratum. 3dly, The columnar form of the lava itself repos- 

 ing on, and being covered by, beds of scorise, ashes, and pumice, 

 which affords a strong argument for the volcanic origin of the 

 columns themselves ; and 4thly, The veins of carbonate of lime and 

 zeolite, which are not found here in solitary pieces as in the vicinity 

 of iEtna and Vesuvius, but are amid the lavas and /';/ the strata of 

 pumice and tufa, and are diffused on the lava itself, and occasionally 

 crystallized in its cavities. 



