226 GEOGNOSY OF EAS? LOTHIAN. 



occur to the north of the Frith of Forth. The rock 

 formations belong to the Transition, Secondary or 

 floetz, and Alluvial classes. The transition rocks 

 are Granite, gneiss, syenite, porphyry, trap, lime- 

 stone, clay-slate, sandstone, and grey-wacke : the 

 secondary or floetz rocks, are Red Sandstone, with 

 its accompanying porphyry, pitchstone, tuff, amyg- 

 daloid, basalt, greenstone, clinkstone, limestone, 

 sflate, coal, and conglomerate ; and the coal forma- 

 tion, with its various subordinate beds and strata 

 of coal, limestone, sandstone, slate, basalt, amygda- 

 loid, tuff, greenstone, &c. ; and the alluvial rocks, 

 are rolled masses, gravel, sand, clay, loam, peat, and 

 calcareous tuffa. 



These classes of rocks present many very impor- 

 tant mineralogical relations, some of which are con- 

 fined to particular limited districts : others extend 

 through more extensive tracts of country, and many 

 of them occur in similar formations in all parts of 

 the globe. 



We shall begin with an account of the minera- 

 logy of East Lothian. 



East Lothian. 



The geographical characters of this county are 

 well known ; and its physiognomy, or external as- 

 pect, has been frequently described. We shall 

 here, therefore, confine ourselves entirely to its mi- 

 neralogical structure. 



