

AMI l I Y 





<>n joined outcrops may then be traceable for 



a lung distan< < iu it her change. Instances of 



tin-, ktn.l sometimes occur among coal-seams. The 



is of a scries of strata now and then 



steal over die lower, to as to c<> what is termed 



i 



an "over ta stru< turc cannot always be ex- 



pressed in plan upon a map, hut is made clear by a 

 section. On the in. .-8) the upper portions of the 



group rlaps upon group / neighbourhood 



of the locality marked O. A section of this pan of the 



mid be as in Fig. 29. 



This strut ture may frequently be met with along the 

 margins of formations deposited in tracts which were 



Inferior OoBtt, which m overlapped by f. *. Inferior Ooliu : A, /. cUy. 



Md i. IUPMOM of Fuller earth. 



undergoing gradual submergence. As the land sank, 

 successive zones were carried down beneath the sea, 

 and the later deposits of the sea- floor were prolonged 

 further and further beyond the limits of the earlier ones, 

 o accompanying section (Fig. 30) shows very clearly 



