UD GEOLOGY OF THE LOTHIANS. 



and shale, which continue as far as Long Green, where they 

 are associated with a great body of greenstone, which ap- 

 pears to hold the same relations to the strata as the others. 

 From this to Hound Point in Linlithgowshire, there are no 

 interesting phenomena exhibited by any of the rocks ; there, 

 however, two veins of greenstone occur, running parallel 

 with the strata, which dip to the west at £26°. These veins 

 in their relations to the stratified rocks, afford exhibitions 

 at once of the violence of their eruptions and of their 

 changing influences, and few points in the Lothians ex- 

 hibit in a more marked manner the various and interest- 

 ing effects of trap rocks on stratified masses. The lowest 

 of the two dykes which are at this point associated with 

 the stratified deposits, rests upon sandstone, while the up- 

 permost reposes upon slate-clay. The trap, as it approaches 

 the sandstone, passes into clay stone felspar, and when in 

 contact with the slate becomes a very compact greenstone. 

 (PI. IX.) The greenstone of these veins is of the common 

 description, and in some places, like several other green- 

 stones associated with the coal strata, emits, on fracturing, 

 a strong bituminous smell. The sandstone on which the 

 lowest trap vein reposes, becomes completely changed as 

 it approaches the greenstone, passing either into granular 

 quartz or hornstone, while a portion of it is partially im- 

 bedded in the greenstone, the fissure produced by its se- 

 paration from the other parts of the stratum having been 

 filled up by the trap. About four feet above the junction 

 of the trap with the sandstone on which it rests, and en- 

 tirely included in it, a mass of sandstone maybe observed ; 

 it is visible for about twenty-four feet, and thins gradually 

 out, from a breadth of six inches to that of a mere thread. 

 The slate-clay, which overlies the uppermost bed of green- 

 stone, is in its position not remarkably altered ; the line of 

 junction is undulating and in several places it is slightly 



