LINOS A AND ITS ROCKS il 



About half-way up a massive stream of black basalt, several meters 

 thick, pierces the tuff, which it has reddened for some distance around. 

 On the west coast, south of Ballata Piatta Point (the northwest 

 corner of the island), six superposed flows are visible, which vary in 

 thickness from one-half to one meter, and are separated from each 

 other by scoriaceous bands. These flows of Monte Ponente, the 

 surface of which is very rough and wholly devoid of cultivation, 

 cover the surface to the northwest, north, and northeast of the cone, 

 and extend into the sea, forming a very jagged shore line. On this 

 lava surface, to the northeast of Monte Ponente and to the northwest 

 of Monte Bandiera, are large knolls and hummocks of rough, large lava 

 blocks, rudely piled on one another. These are apparently the remains 

 of fallen-in lava caverns, or are possibly due to local explosions of 

 steam. 



From the relations of the two it is clear that the lavas and scoriae 

 of Monte Ponente were ejected from the north flank of the already 

 formed tuff cone of Monte Pozzolana, and that the two are geo- 

 graphically but a single mass, though petrographically quite distinct. 

 So far as can be seen, however, there was only a little shifting of the 

 vent northward when the second period was initiated. 



To the east of Monte Ponente is an unnamed cone, for which I 

 propose the name of Monte Raneri, after that of my host. This is 

 73 meters high, and shows a well-defined elliptical crater at the summit. 

 The greater part of this cone is scoriaceous, but some lava flows are 

 visible, and there are many blocks of a compact basalt, which differs 

 from the others on the island in the greater abundance and size of 

 the olivine phenocrysts. Monte Raneri is evidently older than 

 Monte Ponente, as the scoriae of this latter cover the northwest flanks 

 of the former. 



From the characters and relations of the tuff and of the lava and 

 cinder cones, it is quite clear that the former belong to an earlier and 

 distinct period of activity. The tuff cones are all lower than those 

 of the other kind, and their forms have suffered much more from 

 erosion and their craters are not as well preserved, though this is 

 probably due in part to the difference in the materials. Further- 

 more, as we have seen, when the two occur together the tuffs underlie 

 the scoriae and lavas. Also, at Monte Pozzolana and Monte Levante 



