﻿1850.] 



TRIMMER ON THE ERRATICS OF KENT. 



31 



Fig. 4. Fig. 5. 



a, «, n. Chalk. d, d, d. Laminated sand and clay. 



b, b, b. Horizontal sand and clay. e, e, e. Massive sand and gravel. 



c, c, c. Till. /,/,/• Ice-blocks. 



In fig. 3, the laminated clays and sands (b), reposing on the chalk- 

 rock (a), are covered by till (c), in which fragments of a thick sheet 

 of ice, broken in the act of being fixed — blocks of floe-ice (/,/,/) — 

 are imbedded. On the irregular surface of the latter, laminated clays 

 and sands (d) have been conformably deposited, and followed by 

 massive sand and gravel (e). Fig. 4 represents the complicated con- 

 tortions which may be supposed to have resulted from the subsidence 

 of the superincumbent beds into cavities formed by the melting of 

 such ice-blocks as are shown in fig. 3 (/,/,/), the spaces between 

 the blocks being occupied with peaks of till. Lastly, fig. 5 will repre- 

 sent a case of gently curved strata above the till, very common in 

 these cliffs, where the area of the imbedded ice may be supposed to 

 have been great and its thickness small. 



3. On the Origin of the Soils which cover the Chalk o/Kent. 

 By Joshua Trimmer, Esq., F.G.S. 



The origin of soils and their distribution are questions of considerable 

 theoretical interest ; because they involve the history of a terrestrial 

 surface during the period which intervened between the desiccation 

 of the bed of the glacial sea and the commencement of the historic 

 sera of Geology. 



Although, from the proximity of this period to our own times, it is 

 that respecting which we might be supposed to possess the most in- 

 formation, it is nevertheless that which is involved in the greatest 

 obscurity, because it has been studied the least. It has either been 

 neglected as unworthy of notice, or at any rate less attractive than 

 the study of the older fossiliferous series ; or it has been shunned as 

 beset with insuperable difficulties ; whilst in some instances impatient 

 attempts have been made to solve its problems zoologically from in- 

 sufficient data and from an assumed sequence of organic remains. 



The origin of soils and their distribution are likewise questions of 

 great practical importance in the application of Geology to Agri- 

 culture ; because they involve the question whether the composition 

 of soils is identical with that of the beds on which they rest ; and if 



