26 Succession of Formations. 



England from the borders of South Staffordshire and 

 Warwickshire to the neighbourhood of London we 

 discover that the whole series is made of strata, arranged 

 in successive stages more or less in the manner which 

 I have already described, and they consist of similar 

 materials. Thus, through Warwickshire and South 

 Staffordshire, we have rocks formed of New Eed Sand- 

 stone. The red sandstone dips to the east, and is over- 

 laid by New Eed Marl ; the red marl dips also to the 

 east, under beds of blue clay, limestone, and brown 

 marl, forming the various divisions of the Rhsetic beds 

 and Lias ; these pass under a great succession of forma- 

 tions of limestones, clays, and sands, &c., known as the 

 Oolites ; these, in their turn, are overlaid by beds of 

 sand, clay, and chalk, named the Cretaceous series ; 

 which again, in their turn, pass under the Tertiary 

 clays and sands of the London Basin. All these pass 

 fairly under each other in the order thus enumerated. 

 Experience has proved this, for though there are occa- 

 sional interruptions in the completeness of the series, 

 some of the formations being absent in places, yet the 

 order of succession is never inverted, except where, by 

 what may be called geological accidents, in some parts 

 of the world, such as the Alps, great disturbances have 

 locally produced forcible inversions of some of the strata. 

 The Oolites, for example, in England, never lie under 

 the Lias, nor the Cretaceous rocks under the Oolites. 



Observation of the surface in cliffs, railway cuttings, 

 and quarries, therefore proves this general succession of 

 formations, and so does experience in sinking deep wells 

 and mine shafts. If, for example, in parts of the mid- 

 land counties we sink through the Lower Lias, we pass 



question. Some minor formations known further inland are added 

 to make the series more complete. 



