128 COAL-FIELD OF CLACKMANNANSHIRE. 



of a very thin leaf of clay, or of loose sand. The 

 strata betwixt the coals, do sometimes vary in thicks 

 ness, being in one place an inch or two in thickness, 

 and gradually thickening to many fathoms, forming 

 a wedge-shaped bed ; but this is by no means gene- 

 ral. 



With regard to the profile and section herewith 

 produced, Fig. 1. Plate IV., made in the crop and 

 dip-line of the strata, it will be seen from it, that 

 the main coal-field of Clackmannanshire, consists of 

 three subordinate coal-fields, formed by two great 

 slips or dislocations of the strata ; yet, independent- 

 ly of those great dislocations, the strata continue 

 perfectly regular, with very little alteration in the 

 angle of inclination with the horizon. It will be 

 seen from the section, that the south coal-field dips 

 northerly, until interrupted by the great south-slip, 

 which dislocates the coal and accompanying strata 

 no less than 1230 feet, by which all the coals are 

 not only thrown up or out to day, as it is termed 

 by the miners, but are not found again till we pass 

 nearly a mile northward, upon the line of the dip 

 where the same identical coals are found again re- 

 gularly dipping. These coals of the middle field 

 dip regularly northward, until interrupted by the 

 great north slip which dislocates the strata, and 

 throws them up 700 feet. Immediately adjoining 

 which slip, the coals and coal-field commence again 

 and dip regularly northward, to a much greater ex- 

 tent than the other two fields, until they arrive at 



