Proceedhiys. 107 



part of the Weald clay, showing how the sea now and again 

 obtained a footing on the river's domain ; and as time went 

 on we see that each successive border of the continent was 

 covered by the sea which advanced from the south-east, and 

 the deposits became entirely marine. Now the character of 

 these succeeding marine deposits showed that a fight for 

 supremacy was still going on between dry land and ocean, 

 for the Lower Greensand contains pebbles of quartz, jasper, 

 and slate of a similar kind to those brought down by the 

 Wealden river, and these were doubtless derived from the 

 wearing down of this great north-western continent. 



There is an important feature displayed throughout these 

 Lower Greensands which ought to be carefully noted. This 

 is what is termed false-bedding. Wherever we see this we 

 may feel sure that the deposits in which it occurs were laid 

 down in a sea which was shallow, and consequently subject 

 to be disturbed by varying currents. In the deposits formed 

 at the bottom of a deep and quiet sea we do not get false 

 bedding, the strata appearing parallel to one another under 

 these circumstances. This false bedding existing throughout 

 the Lower Greensands is evidence of itself that the land was 

 as yet at no great distance. We have other signs that the 

 continent was still in existence by the occurrence of drift- 

 wood of trees, such as we find in the river-deposits. These 

 no doubt grew on the continent and were borne out to sea by 

 the overflowing river, whose mouth had now receded further 

 and further away, and there they floated about till they 

 became water-logged and sank. Bodies of the Iguanodon, 

 too, were floated out to sea, for we find their bones buried in 

 the Greensand, as at Maidstone. 



I must say a word or two of the reason why the deposits 

 of sand obtained the name of "green sands." We find inter- 

 spersed throughout certain beds of the formation a large 

 quantity of small rounded particles of an earthy substance of 

 dark green colour. On analysis this is found to contain 

 sihca, alumina, and oxide of iron, which, chemically combined 

 together, form the mineral Glauconite. If these particles are 

 examined under the microscope, they are seen to be casts of 



