84 ON THE FOSSIL TREES IN A MARL PIT AT HANLEY. 



and died on the identical spot we saw them standing on. 

 They could not have been drifted into the position in which 

 we saw them: if they had we should naturally expect to find 

 evidence in the marl in which they were entombed. After 

 a careful examination I cannot arrive at any other conclu- 

 sion than that the marl in which they were enveloped is 

 nothing more than sediment quietly and tranquilly deposited 

 in water. 



Assuming, then, that these trees grew on the spot we saw 

 them standing on, let us suppose that the bed on which 

 they stood was raised above the surface of the water as 

 an extensive plain : this would gradually settle down and 

 become submerged : it would then become covered with 

 the sediment which was being deposited from the turbid 

 waters, and gradually covered up. This sediment accumu- 

 lated until a new surface was formed. Here, then, another 

 forest of plants and trees would grow. Then an interval 

 of rest, and one of the beds of coal which you saw in the 

 marl pit would be formed. The same process as before 

 would then go on, and the second bed of coal would be 

 formed ; and so similar intervals of repose, with occasional 

 subsidences, would be repeated until the whole of the 

 seventy or eighty feet of strata we saw was deposited. 



But if for the formation of this eighty feet of strata so 

 many changes and intervals of repose were required, what, 

 I ask, must have been the changes which have taken place 

 during the deposition of the strata which compose the 

 North Staffordshire coalfield ? In this coalfield we have, 

 according to Mr. Hull, some thirty beds of workable coal, 

 besides a great number of thin beds which are distributed 

 throughout some 5,000 or 6,000 feet of strata. Each of 

 these beds represents so many breaks or periods of repose. 



