Sections in Coal Seams at Odsal, nr. Bradford. 63 
ins., runs up in a convex manner, as shown in sketch. The 
material inside the lens of the split is grey shale similar to 
that above the coal seam, but whereas the bedding in the lens 
is horizontal, that above the split follows the convex form 
of the upper component. Fig. 4 gives a second section in 
the middle excavation, and this shows a little more of the split. 
The three excavations are at successively lower levels, the one 
marked I being lowest. Figs. 2 and 3 give sections across 
the ends of the split, where there is merely a hunching up of 
the seam with a consequent upfolding of the bedding of the 
shale. These four sections taken together evidently mark out 
the extent of the split. Figs. 2 and 5 give the ends, and Figs. 
3 and 4 give sections across the middle. An attempt is made 
in Fig. 1 to mark out the extent of this split, and from it it 
will be seen that it is roughly elliptical, about 40 yards long 
and over 10 yards broad. A general reconstuction of the split 
is given in Fig. 6, as it would appear in a section across the 
middle of the complete split. 
Such split seams are not by any means new. They are 
known in most of the coalfields, and have given trouble. Prof. 
P. F. Kendall has worked out some of the splits in the York- 
shire coalfield in detail, and for a description of one of the 
larger ones — the Whitwood Split — reference should be made 
to his paper ‘ On the Splitting of Coal Seams by Partings of 
Dirt, Pt. 1, Splits that Rejoin/ Trans Inst. Mining Engineers , 
Yol. LIV., Pt. 5, pp. 460-479. He offers an explanation some- 
what as follows. Imagine a layer of peat forming, and after 
some time traversed by a stream. This stream will cut out a 
channel which will eventually be filled by sand or mud. The 
river may cease to run, and the peat formation will continue 
over the top of the whole. Thus will occur two layers of 
peat inseparable in its normal development, but separated at 
one place by a parting of dirt, plano-convex in form, with the 
plane surface uppermost. The whole becomes covered by 
great thicknesses of sediment, and the peat becomes compressed. 
But the peat and sediment are not compressible to the same 
extent. Prof. Kendall considers that the peat may be com- 
pressed into ^0 th of its bulk on turning into coal, whereas 
the sediment loses very little in size during the compression. 
The result after compression is a coal seam parted where the 
channel was by a parting of sediment, plano-convex in shape, 
but with the convexity upwards. This reversal of the lens 
is well displayed in this case at Truncliffe Gate. The only 
difficuly appears to be in the fact that owing to the very small 
size of this split, and the fact that it is elliptical in form, 
it could not possibly have been caused by a stream cutting out 
a channel in the peaty substance suggested. It is more 
probable that there has been some depression in the peaty 
substance being infilled with sediment before the formation 
of further peaty material on the top. The fact that the normal 
1922 Feb. 1 
