108 GEOLOGY OF THE LOTHIANS. 



and the productus is of very frequent occurrence. At 

 Galla Braes, the limestone is penetrated by a large mass of 

 earthy greenstone running parallel with the strata. Though 

 the covered state of the quarry completely obscures the 

 exact relations of these rocks ; still, from the fact of the 

 greenstone appearing only on one side of the quarry, it is 

 probable that, if circumstances allowed a complete exami- 

 nation, it would be found to wedge out. From near Galla 

 Braes to Mount Eerie, there is a very long and deep open- 

 ing, exposing strata of clay, ironstone, sandstone, and lime- 

 stone, dipping under a thick overlying mass of greenstone, 

 and abutting against some trap cliffs, which occur at a few 

 hundred yards distance. At the eastern extremity of this 

 quarry, working operations have exposed the direct junction 

 of the trap with the slate-clay, but there is no mark of al- 

 teration in position or structure ; the slate-clay however 

 assumes, to the distance of two feet from the trap, a yellow- 

 ish-brown colour. On the side of the road leading from 

 Mount Eerie to Bathgate, felspathose greenstone occurs in- 

 timately associated with fine granular slaty tufa, and con- 

 tains imbedded masses of elastic mineral pitch. A short 

 distance to the north of Mount Eerie, in the north and south 

 Silver-Mine quarries, the strata of slate, ironstone, and lime- 

 stone, are well exposed, but exhibit no junction with the 

 trap rocks which cover them, and against which they abut. 

 The limestone of these two quarries is of a dark bluish- 

 grey colour ; while that of Kirkton, Galla Braes, and Mount 

 Eerie, is yellowish-grey, and passes into a black flint, which 

 generally contains well preserved madrepores. Between 

 the Silver Mine and Wardlaw, there are no openings 

 which afford junctions of the stratified rocks with the 

 greenstone ; there, however, the trap is found connected 

 with the limestone, both as a vein and also as an overlying 



