QT7AKTZITE BOTJLDEPvS I3T THE R0GEK MIXE AT DTTEXttETEED. 601 



The roof in which, these boulders are partly imbedded (part in 

 roof and part in coal) consists of a grey shale, of an argillaceous 

 character, with dark shades of carbonaceous shale forming layers 

 varying in colour and from three to four feet in thickness up to a 

 black parting, above which is a light-grey shale with rock binds; the 

 floor upon which the Roger coal rests is an inferior fire-clay mixed 

 with bands of coaly matter. 



Pigs. 2-5. — Boulders in Coal, in the Roger Mine, 

 Fig. 2. Fig. 8. 



a. Metal with rock-bands. c. Soft holing dirt. 



b. Coal. d. Inferior fire-clay. 



The boulders are coal-blackened only as far as they are buried 

 in the coal, and appear to have been dropped quietly on to a soft 

 bottom ; in one instance the boulder stood edgeway up, not flat 

 down as the others were. 



The sectional sketches (figs. 2-5) show the positions the boulders 

 occupied in the measures in which they were found, they being 

 foreign to the surrounding strata, much harder, different in form 

 and structure. 



No. 2 boulder (fig. 2) found imbedded in the coal, the upper edge 



