D I L 



[137] 



D I L 



dike ; in others, to that of three or 

 four yards only. Sometimes the 

 coal first becomes sooty, and at 

 length assumes the appearance of 

 coke. 



DiLifviAL. (diluvialis, Lat.) Relating 

 to the deluge. A term introduced 

 by Professor Buckland to distin- 

 guish accumulations consequent on 

 the deluge. " It is always," says 

 Dr. Mantell, " in diluvial beds 

 spread over the surface of plains, 

 or accumulated in the bottoms of 

 valleys, that the teeth and bones of 

 mammalia have been discovered in 

 various parts of England." 



DILTT'VIAL DEPOSITS. "Next in order 

 to the alluvial deposits/' says the 

 Eev. Dean Conybeare, "we find a 

 mantle, as it were, of sand and 

 gravel indifferently covering all 

 the solid strata, and evidently 

 derived from some convulsion which 

 has lacerated and partially broken 

 up those strata, inasmuch as its 

 materials are demonstratively frag- 

 ments of the subjacent rocks, 

 rounded by attrition. The frag- 

 mented rocks constituting these 

 gravel deposits are heaped con- 

 fusedly together, but still in such 

 a manner that the fragments of any 

 particular rock will be found most 

 abundantly in the gravel of those 

 districts, where the parent rock 

 itself appears in titu among the 

 strata. In these deposits, and 

 almost in these alone, the remains 

 of numerous land animals are 

 found, many of them belonging to 

 extinct species, and many others 

 no longer indigenous to the coun- 

 tries where their remains are thus 

 discovered." 



DILU'VIALIST. One who attributes 

 certain effects, denied by others, as 

 consequent on theNoachian deluge. 



DILUVIAN. (Lat.) A name applied 

 by Professor Buckland to the super- 

 ficial beds of gravel, clay, and sand 

 which he considers to have been 

 produced by the Noachian deluge ; 



loose and water-worn strata not at 

 all consolidated, and deposited by 

 an inundation of water. 



The term Diluvium has been 

 applied to the general covering of 

 debris indiscriminately thrown to- 

 gether from all the strata by an 

 inundation which must have swept 

 over them universally, which in- 

 undation, known as the Noachian 

 deluge, was the last great geological 

 change to which the surface of our 

 planet appears to have been 

 exposed. By this name it is 

 proposed to distinguish it from the 

 partial debris produced by causes 

 now in operation, and to which the 

 term Alluvium is assigned. 



Sir R. Murchison observes 

 "those coarse and sometimes far 

 transported fragments, to which 

 some geologists apply the term 

 diluvium, to avoid misconstruction, 

 I call drift. See Drift. 



The Hon. Mr. Strangways ob- 

 serves "I need not say what is 

 intended by the term Diluvium; 

 it is meant to express that super- 

 ficial deposit which covers every- 

 thing, and is composed of almost 

 everything. Its composition and 

 thickness are very various : the 

 latter amounting to thirty, forty, 

 or even fifty feet. In some 

 instances it seems to form entire 

 hills. It is usually thickest in the 

 vallies, or on the flat summits 

 of some of the hills. Its compo- 

 sition, much as it differs in different 

 places, may be considered twofold ; 

 first, as the debris of rocks upon 

 which, or in the neighbourhood of 

 which, it is accumulated j secondly, 

 as that of a set of rocks totally 

 foreign to the country, the analo- 

 gies of some of which have been 

 recognised in situ at a vast distance, 

 while others remain yet to be 

 identified." 



For the purpose of impressing 



