Sheppard : The Making of East Yorkshire. 107 



these. Such changes, small and insignificant though they ma}^ 

 appear to be, unquestionably tell in time. A farmer on our 

 coast, or a ship's captain familiar with the Humber, could tell 

 more graphically of the changes they are familiar with, yet 

 these changes have taken place within a comparatively short 

 period. Compared with geological time our centuries are but 

 seconds. The formation and erosion and re-formation time 

 after time of the various rocks, as well as for the gradual 

 evolution of animal and plant life, w^hose remains are therein 

 entombed, require a period of time which, if numbered in 

 years or even centuries, would be far too great to be 

 comprehended. In the geological history of East Yorkshire, 

 therefore, we must remember that w^e are starting at a point 

 very late in the history of the globe. The remains of animals 

 and plants preserved in the Liassic strata, w'hich are the 

 oldest I propose to touch upon, indicate a very forward state of 

 advancem.ent. The relative position of the Liassic rocks upon 

 the older rocks shows that they w^ere formed in a comparatively 

 recent period, and great as are the changes which have taken 

 place between then and now^, these are small and insignificant 

 as compared with the upheavals and depressions which had 

 taken place prior to the formation of the Liassic beds. 



Another advantage in studying the rocks of East Yorkshire 

 is the fact that they are exposed in the cliflfs in w^onderfuUy 

 regular order. The beds are deposited one upon another just 

 as one might pile some volumes of books ; and there is a 

 gradual dip or slope of the rocks to the south-east, which 

 enables one to walk along the cliffs from south to north and to 

 examine each bed in its proper order as it presents its surface in 

 the cliff line. So admirable is this arrangement in Yorkshire 

 that it might almost be said that the sections have been arranged 

 for the convenience of the geologist ! 



The Lias, as the name implies, refers to those rocks, which 

 occur in thin layers, exposed in the cliffs between Whitby and 

 Robin Hood's Bay, and inland at certain points. Near Hull 

 they can be examined at North Cave and Cliff, at which places 

 are lower beds in the series than represented in the cliff sections. 

 The layers in the rocks are particularly well shown in natural 

 sections from the fact that they consist alternately of limestone 

 and shale. The latter material, being much softer than the 

 former, is easily eroded, resulting in prominent layers of lime- 

 stone, perfectly parallel to each other, being divided by the soft 

 shale beds. These are the deposits which were formerly worked 



1905 April I. 



