THE PERMIAN PERIOD. - 1 93 



of iron, and often accompanied by beds of gypsum or deposits 

 of salt. In strata of this nature few or no fossils are found j 

 but their shallow-water origin is sufficiently proved by the 

 presence of the footprints of terrestrial animals, accompanied 

 in some cases by well - defined " ripple-marks." Along with 

 these are occasionally found massive breccias, holding larger 

 or smaller blocks derived from the older formations; and these 

 have been supposed to represent an old " boulder-clay," and 

 thus to indicate the prevalence of an arctic climate. Beds of 

 this nature must also have been deposited in shallow water. 

 In all regions, however, where the Permian formation is well 

 developed, one of its most characteristic members is a Mag- 

 nesian limestone, often highly and fantastically concretionary, 

 but containing numerous remains of genuine marine animals, 

 and clearly indicating that it was deposited beneath a mod- 

 erate depth of salt water. 



It is not necessary to consider here whether this formation 

 can be retained as a distinct division of the geological series. 

 The name oi Pe7'inian was given to it by Sir Roderick Murchi- 

 son, from the province of Perm in Russia, where rocks of this 

 age are extensively developed. Formerly these rocks were 

 grouped with the succeeding formation of the Trias under the 

 common name of " New Red Sandstone." This name was 

 given them because they contain a good deal of red sandstone, 

 and because they are superior to the Carboniferous rocks, 

 while the Old Red Sandstone is inferior. Nowadays, how- 

 ever, the term " Nev/ Red Sandstone " is rarely employed, 

 unless it be for red sandstones and associated rocks, which 

 are seen to overlie the Coal-measures, but which contain no 

 fossils by which their exact age may be made out. Under 

 these circumstances, it is sometimes convenient to employ the 

 term '' New Red Sandstone." The New Red, however, of the 

 older geologists, is now broken up into the two formations of 

 the Permian and Triassic rocks — the former being usually con- 

 sidered as the top of the Palaeozoic series, and the latter con- 

 stituting the base of the Mesozoic. 



In many instances, the Permian rocks are seen to repose 

 unconformably upon the underlying Carboniferous, from which 

 they can in addition be readily separated by their lithological 

 characters. In other instances, however, the Coal-measures 

 terminate upwards in red rocks, not distinguishable by their 

 mineral characters from the Permian ; and in other cases no 

 physical discordance between the Carboniferous and Per- 

 mian strata can be detected. As a general rule, also, the 

 Permian rocks appear to pass upwards conformably into the 



