the Upper and Lower Drift of the Eastern Counties. 397 



Maestricht, and thence into the Campine of Belgium. Here, he 

 adds, the sand of which the deposit is formed did not probably 

 come from any great distance, being to all appearance derived 

 from the degradation of the sands of the older Tertiaries, upon 

 which it rests, both at Maestricht and in part of the Campine ; 

 while included in it are an abundance of flints, intermixed with 

 a proportion of erratics, derived from the Ardennes and from the 

 mountains skirting the Rhine. 



In describing this deposit as covering the plateau of St. 

 Peter's Mount at Maestricht, M. d'Archiac observes that its 

 included erratics consist mostly of quartzites, of sizes varying 

 from that of the fist to that of a walnut ; and he adds that he 

 regards the deposit as of the same age as the erratic beds, con- 

 taining mammalian remains, which occur at the bottom of the 

 valleys, and even on their sides, and on some of the surrounding 

 plateaux, from the Rhine to the Channel, and which on the 

 English side crown nearly all the chalk cliffs and detached ter- 

 tiaries that overlie them. 



Along the road from Tongres to Maestricht, adds M. d'Ar- 

 chiac, this diluvium disappears under another Drift-deposit of 

 yellow sandy clay, true Lehm or ancient alluvium which envelopes 

 the country like a mantle to a thickness of from eight to ten 

 metres. 



He then extracts from the ' Coup d'CEil sur la Geologic de la 

 Belgique,' of M. d'Omalius d'Halloy, the description of that 

 geologist, given in almost similar terms to those adopted by M. 

 Elie de Beaumont, — the distinction between the overlying Loess 

 or ancient alluvium, and the underlying sandy beds with erratics, 

 being particularly shown. 



Although, according to the view I take of the division that 

 exists between deposits that are older and those that are newer 

 than the valleys, there is in M. d'Archiac's identification of the 

 Campinian sand with the gravels that cap the deposits along 

 the coast of England a confusion of beds of different ages *, 

 yet it is apparent from the description of the Belgian beds 

 given by himself, as well as from those of the eminent geologists 

 quoted by him, that the Campinian sands, with their associated 

 and included beds of rolled stones, pass under the Loess, but are 

 distinctly divided from it in the same manner as I have shown 

 to be the case with the lower Drift and Boulder-clay. The elabo- 



* The lower- Drift sands and gravels capping the Tertiaries of East Anglia, 

 and which underlie the Boulder -clay, are, like that deposit, according to my 

 views, older than the valleys ; but the gravels and other accumulations of 

 debris along the south coast, that sometimes cap the Chalk and sometimes 

 the Tertiaries, are newer than the valleys of East Anglia, and even, as I 

 believe, to a certain extent differ in age among themselves. 



