320 Clmule H. B. E'pps— Jointing in Chnlk. 



Dovrefekls is further good evidence that the elevation was not 

 uniform, but must have diminished as we travel eastward from the 

 high mountains towards the coast. Munthe's researches prove, as 

 he says, that the isobases for the Litorina deposits show a gradual 

 rise in their level from the Stockholm district inwards towards the 

 central districts (id., p. 11). Again, he speaks of the upheaval of 

 the land being greatest the further one goes towards the central 

 part of Scandinavia. This is in accordance with the conclusions of 

 De Geers. The greatest elevation, in fact, occurs between lats. 62 

 and 64, from which it diminishes both northwards and southwards. 



These facts seem conclusive that the shell-beds testify to an actual 

 alteration in level of the solid crust of the earth, and not merely to 

 a moving envelope of water. 



VI. — Some Examples of Jointing in Chalk. 



By Claude H. B. Epps, B.A., The College, Wiucliester. 



(PLATE XVIII.) 



rriHE structures described in this note occur in a laige chalk-pit 

 _L close to Hensting Farm, by Owlesbury, near Winchester. The 

 east face is vertical, about forty feet high ; near the bottom, along 

 a well-marked bed of the Chalk, some deposits of gravel and clay 

 are exposed at varying distances from each other ; three of these 

 are small, two rather larger. On the south face there is a similar 

 deposit near the top of the pit, but this is inaccessible, and no special 

 structure can be seen in the surrounding Chalk owing to its 

 conversion into subsoil. 



Of the two larger deposits one is almost hidden by debris, but the 

 other shows some points of interest. It consists of a ridge of sand 

 and clay, projecting obliquely from the face of the cliff for a distance 

 of some eight feet, the surrounding chalk having been removed ; 

 a little digging shows that it is a true ' fossil watercourse,' not merely 

 fallen material. In section it is roughly circular, about two feet 

 in diameter ; the greater part consists of a dark brown sandy clay 

 showing current-bedding, with somewhat fine gravel, the grains of 

 which are not much rounded above, and pieces of chalk and a few 

 flints which have fallen from the roof of the channel into the stream. 



The Chalk through which the underground stream once ran is 

 fairly hard and homogeneous, consisting of the Belemnitella quadrata 

 zone ; it dips 5° S., but the bedding is otherwise undisturbed. 

 Several bands of flint occur higher up in the pit, but low down there 

 are few. 



Within a distance of seven or eight feet from the deposit the 

 Chalk shows strikingly regular joints, which form three distinct sets. 

 The first set consists of roughly cylindrical joints, co-axial with the 

 deposit ; the second of radiating planes, perpendicular to the first set ; 

 and the third of planes transverse to the axis of the deposit. As 

 the face of the pit is oblique to the former course of the stream 

 the first set appear as portions of ellipses, unless the observer is 



