Robert Campbell — South-Eastern Kincardineshire. 63 



have caused the first outbreak of Herdubreid, not the offshoot of an 

 exploding mass of gases accompanied only by lavas. In this fact lies 

 the great difference between Daubree's experiment and the physics of 

 eruption in the case of Herdubreid. AVith Herdubreid the cylindrical 

 form of the pipe must therefore be due to other reasons than the ones 

 adduced in the case of explosions. 



Different reasons are possible. The most probable seems to me in 

 accordance with Suess's and Branca's opinions, that the rising column 

 of lava has forced its own way through the superincumbent crust 

 until it reached the surface. But this or other explanations which 

 see the moving force in the rising magma itself seem to me to negative 

 the possibility of a fissure as a line of weakness being the outlet of an 

 upward pressing magma, which would not in doing so assume the 

 shape of a dyke, but would wear out a perfectly cylindrical canal along 

 the fissure on its way upwards. 



There are many more reasons to prove the fissureless nature of the 

 Schild volcanoes in Iceland, but it is not the object of this paper to 

 give them. The reader will find them published in the above- 

 mentioned papers. Here I only wanted to show that I was well 

 aware that this probably unique example in the world of a volcano 

 being exposed on all sides a few hundred metres below its base, would 

 be a serious objection to the theory which sees a fracture in the 

 earth's crust as the necessary primary origin of all volcanoes. 

 I therefore was especially careful in examining all the eventualities 

 which could possibly have concealed a fissure below the volcano, but 

 all observations as well as theoretical conclusions do not leave the 

 least doubt that in this case volcanic force found its way to the 

 surface without the help of a surface fissure. Furthermore, theoretical 

 conclusions and comparisons of the products and the outer appearance 

 of these lava volcanoes with the mechanics of eruption make it most 

 probable to me that not even in the deeper parts of the crust 

 a fracture has served them as a line of weakness ; but that, probably 

 by melting its way through the crust, the lava forced its own way from 

 the magma basin below up to the eruptive point at the surface. 



IY. — Preliminary Note on the Geology of South - Eastern 

 Kincardineshire. 



By Eobert Campbell, M.A., B.Sc, Geological Department, University of 



Edinburgh. 



TPHE district under consideration embraces that part of the county 

 JL of Kincardine which lies south of the Highland fault. Excellent 

 maps on the 1 inch and \ inch scale have been issued by H.M. Geological 

 Survey, but no detailed description of the geology of the area has yet 

 been published. Most of my vacations during the past three years 

 have been spent in studying the geology of this interesting region, 

 and although the work, which has included detailed mapping of the 

 whole area on the 6 inch scale, is not yet complete, several points 

 have been made out, the importance of which has led to the publication 

 of this preliminary note. 



