. Ill, DIST. CHAR. Soil. 161 



or less consolidated limestones, chalk, marls, and 

 clays rarely, perhaps, some sandstone strata. These 

 appear to have been formed by depositions from the 

 sea, when its surface was considerably higher than 

 at present ; but lower than in the first ages of the 

 globe, (v. p. .13-38.) 



The semimarigenous exhibit marine reliquia ac- 

 companied with vegetal remains, either in the same 

 stratum, or respectively in strata alternating with 

 each other, (v. p. 29-32. and notes ft p. 29. f P- 

 31.) They are chiefly marls, clays, sandstone, and 

 some coal-strata. 



The alluvial f contain 'vegetal reliquia alone, or 

 mixed v?iihfiuviatile shells and the remains of fresh- 

 water jlsh the strata, principally, sandstone, clay, 

 marls, marlite, shales, ironstone, and coal. Such 

 soils have every appearance of having been deposited 

 from large expansions of fresh water, collected in 

 the hollow or vale-like depressions of more ancient 

 strata ff. 



t We not only call those soils alluvial that owe their origin to 

 sudden inundations of rivers, &c. but also those which have been 

 deposited by deep and more permanent collections of fresh water 

 (v- p. 32. b. 14.). The reader must be careful, therefore, not to sup- 

 pose, we confound the alluvial among the less ancient secondary 

 soils, with the modern alluvial of the two following sections ; and 

 which, in most geological works, are exclusively distinguished by 

 the title in question. 



|t This is particularly observaMe in coal soils, v. William's 

 Mineral Kingdom. V. I. p. 105. 



Y 



