EXPLANATION OF PLATES. J 59 



space : this, however, we refrained from doing, as the appa- 

 rent accuracy might in many instances have been found by 

 other observers to have no existence. Vertical strata are de- 

 noted by a line shewing the direction, and by this mark -f- . 



Plate Explanatory of the colours used in the sections. 

 Plate I. Fig. 1. — Unconformable position of the red sandstone 

 and transition strata. Heriot Water, Berwickshire. 

 Fig. 2. — Section near Red Heugh exhibiting the same 

 appearances. 

 II. Fig. 1. — Sectional view of another junction of the tran- 

 sition and secondary rocks, near Red Heugh. 

 Fig. 2. — Ground plan affording the same appearances. 

 Red Heugh. 



III. Fig. 1. — Greenstone traversing and overlying sandstone. 



St Leonard's Hill. 

 Fig. 2. — Greenstone enveloping masses of sandstone and 



overlying arenaceous limestone. Salisbury Crags. 



(The masses of sandstone are on a larger scale than 



the rest of the section.) 

 Fig. 3. — Greenstone overlying and fracturing arenaceous 

 limestone. Salisbury Crags. 



IV. Section of the central part of Salisbury Crags. Here 



the greenstone is found to have both contorted and 

 enveloped masses of the sandstone. Upraised strata 

 of sandstone are also found overlying it. 

 V. Fig 1. — Shift in sandstone. Cat Nick, Salisbury Crags, 



Fig. 2. — Vein of greenstone traversing the greenstone 

 and sandstone of Salisbury Crags. This point is one 

 of the few in the Lothians where there are indications 

 that the trap-rocks of the district are the formation 

 of more than one epoch. 

 VI. Fig. 1. — Sectional view of the northern part of Salisbury 

 Crags. 



Fig. 2. — Greenstone porphyry overlying and enveloping 

 strata of white sandstone. Northern front of Arthur 

 Seat. 

 VII. Fig. 1. — Sectional view of Arthur Seat, partly ideal. 



Fig. 2. — Section shewing the probable relations of the 

 basalt which forms the summit of Arthur Seat, to the 

 greenstone and sandstone of Salisbury Crags. 



Fig. 3. — Section from the Calton Hill to Leith. (The 

 greenstone rocks of Lochend and Restalrig are on a 

 larger scale than the rest of the section.) 

 VIII. Fig. 1. — Greenstone traversing shale. St George's 

 Well, Water of Leith. 



Fig. 2. — Ground plan of greenstone vein traversing 

 shale. St George's Well, Water of Leith. 



