ALLIED PHENOMENA IN ENGLAND. 53 
the mud, which also sealed up the coal bed. Toward the dip these 
masses become fewer and smaller. 
ENGLAND 
Figure 20 illustrates a section in the ‘‘ Main” coal at Moira, Leicester- 
shire, England. 
The plane or surface separating the two distinct masses of clayey ma- 
terial, filling the opening made in 
the coal, together with the reverse 
crumpling to which these intrusive 
masses have been subjected, points 
to the gash having been formed at 
two periods, the smaller and paler 
deposit indicating by its position 
that it is probably the older of the 
two. 
The forked vein of clay shown in 
figure 21 was observed by the writer Freure 20.—Section in the “ Main” Coal of Leices- 
in the same seam as the last and LSI Ena: 
about 3 miles distant from it. The Or geevor lcthmnatiualsize 
only explanation seems to be that the coal was bent and opened a crack 
in its lower layers, into which the soft under clay swelled until the cracks 
were filled solid. 
Figure 22 apparently illustrates a combination of the phenomena seen 
in the sections shown in figures 20 and 21, for here we have the coal bed 
Figure 21.—Forked Clay-vein. Figure 22.—Combination Clay-vein. 
Y: Y- 
One-seventieth natural size. One twenty-fifth natural size. 
cracked and pulled apart from top to bottom. The ultimate effect of 
this stretching was to allow the clay floor to swell and the darker over- 
lying shale to be squeezed down into the opening. ‘This section was ob- 
served at a depth of 1,075 feet and within 20 feet horizontally of a fault 
having a vertical throw of 250) feet. Possibly the pull upon the hanging 
