May 30, 1 901] 



NA TURE 



ground is well shown in some of the illustrations, but the 

 author does not believe that Monte Vulture has had its 

 site determined by the stupendous linear fracture which 

 some theorists have imagined to extend eastwards from 

 Vesuvius. He has satisfied himself, by a study of the 

 geological structure of the surrounding country, that no 

 trace of any such dominant dislocation exists. 



The various rocks of the volcanic pile are then de- 

 scribed in some detail. They are shown to form a 

 numerous and continuous series of varieties between the 

 two extreme limits of trachytoid phonolites, on the one 

 hand, and basalts on the other. The principal types of 

 lava are thus arranged : Hauyne-phonolite, anorthoclase- 

 phonolite, hauyne-tephrite, leuco-hauyne-tephrite, leuco- 

 hauyne-basanite, leucitic basalt, leucitite, nephelmite, 

 hauynophyre. Each of these types is fully described and 

 is illustrated by excellent plates of its microscopic struc- 

 ture. A section is devoted to the characters of the 

 agglomerates by which the lavas are accompanied, and 

 another to the inclusions contained both in the lavas and 

 the fragmental materials, some of which were doubtless 

 derived from the underlying sedimentary platform, others 

 probably represent portions of the subterranean magma 

 which have acquired a granitoid structure at a great 

 depth, while in some cases their origin is doubtful. 



etical questions of volcanism. He insists on the total 

 independence of the eruptions of this centre, which he 

 thinks had no direct communication with those of any- 

 other. He can find no trace of the great connecting 

 fissures which have been supposed to link together all 

 the old and modern volcanoes of Southern Italy. He 

 regards the eruptions of this centre as having begun 

 long after the great orogenic movements that gave rise 

 to the Apennine chain, and at a time when perennial 

 snows and glaciers still lingered on the surrounding 

 heights. Phonolitic lavas first made their appearance, 

 followed by tephrites, basanites and basalts, which form, 

 the great mass of the mountain. Two peripheral vents 

 can be distinguished, one anterior, the other posterior 

 to the formation of the great central cone. The last 

 stupendous manifestation of volcanic energy seems to- 

 have been the explosion which blew out the great 

 crater in which the two crater-lakes of Monticchio now 

 lie (Fig. I). 



M. de Lorenzo acknowledges the important services 

 rendered to him by his friend Prof. Riva— the young 

 and accomplished mineralogist of Pavia whose petro- 

 graphical assistance and photographic skill were freely 

 given in the preparation of this important monograph. 

 The other memoir above cited is a ioint production of 



Having described the materials of the volcanic pile the 

 author next furnishes an account of the way in which 

 they have been built up into the huge mass of Monte 

 \'ulture. In a long and interesting section of the paper 

 the structure and probable history of the mountain are 

 discussed, and the position of its various rocks and some 

 of the successive phases in the evolution of the topo- 

 graphy are explained in diagrams inserted in the text. 

 The next division treats of the lakes which, partly in 

 consequence of the volcanic disturbances, were formed 

 in some number and of considerable size during Pleisto- 

 cene time. This subject had already been treated by 

 M. de Lorenzo in a separate memoir \Atti Accad. 

 Scien. Napoli, 1898) in which he had shown that Southern 

 Italy in Quaternary time was dotted over with large and 

 small basins of fresh water. Whether formed in conse- 

 quence of changes in the topography produced by the 

 volcanic eruptions or existing before these eruptions 

 began, the lakes around Monte \'ulture were more or less 

 filled up with limno-volcanic tuffs containing fresh-water 

 shells and likewise remains of Ehphas an/igutis, Hippo- 

 potamus major, Ursiis spelaeiis, Felis spelaea, Hyena 

 spelaea and Cerviis elephas. 



In a final section the author states what he believes to 

 be the bearing of the history of Monte X'ulture on theor- 



NO. 1648, VOL. 64] 



the two observers. It is entitled " II Cratere di Vivara 

 nelle Isole Flegree," and forms No. 8 in the same 

 volume of the Tramaclions of the Naples Academy. 

 It begins with an interesting historical introduction 

 and then at once enters on a discussion of the rocks 

 of which the remarkable island is composed. These 

 consist entirely of fragmentary materials which have 

 been heaped up around a crater, as in the other vol- 

 canic cones of the Campi Phlegrwi. A careful account 

 is first given of the coarse breccias or agglomerates, 

 which include blocks of trachytic obsidian, sanidinites 

 with quartz and catoforite, anorthoclase-trachytes with 

 a:girine, augitic trachytes, mica-trachytes, andesitic 

 trachytes, basalts, trachydolerites, rocks of dioritic type 

 (monzonites) and other varieties. Full petrographical de- 

 scriptions of these rocks, together with micro-photographs 

 of their internal structure, are given. The varieties of 

 pumice, lapilli and tuff are likewise detailed. It is shown 

 that the eruptions of Vivara, unlike those of the neigh- 

 bouring region, did not consist solely of trachytic 

 material, but discharged an admixture of a trachytic 

 and a basaltic magma, so as to have heaped up a rich 

 assortment of the most remarkable rocks, beginning with 

 a quartziferous sanidinite and passing through various 

 trachytic types to normal olivine-basalt. The relations of 



