REPORT OF MEETINGS FOR 1905 259 



submerged. One of these flowed in the direction of Arthur's 

 Seat, and now forms what is known as the Long Row. This 

 was succeeded by a period of quiescence, during which another 

 band of geyserite was formed, which may be seen on the 

 South side of the Queen's Park, between Windy Goul and 

 the Queen's Drive. Various successive eruptions of a more 

 or less violent character supervened, ere another basalt lava 

 flow in the direction of the Queen's Park set in. Submergence 

 still continued, and perhaps kept pace with the growth of 

 the volcano, as the beds overlying the last named lava consist 

 of stratified tuff, in which remains of Rhizodus and trans- 

 ported fragments of Lepidodendron occur. In these beds, 

 which are, as a rule, fine grained and of only a few feet in 

 thickness, are found large ejected blocks, one of which, seen 

 just below St. Anthony's Chapel, may really be a volcanic 

 bomb. This thin bed of tuff is succeeded on Arthur's Seat 

 by a compact basalt lava, very columnar in character, showing 

 traces of fluxion structure on its weathered surface, and 

 weathering a bright rust-red colour. Another bed of geyserite 

 accompanied by a thin band of tuff succeeds, and is followed 

 by a remarkably brecciated lava. Three other lava flows 

 poured from the Edinburgh volcano in the direction of what 

 is now known as the Queen's Park, of which the older two 

 are basalts, and the higher a true andesite, containing large 

 tabular crystals of Labradorite. This is the rock which forms 

 most of the Eastern side of Arthur's Seat, and which both 

 caps and forms the East slope of Dunsappie. 



Contemporaneously with the eruption of these lavas and 



tuffs, there was intruded underground three 

 Intrusive sheets or sills of rock, the lowest of which is 

 Rocks. a porphyritic basalt, forming the rock of St. 



Leonard's Crags and Heriot Mount. This rock 

 occurs in the form of a wedge, with its base towards the 

 West, and it cuts across the strata from below upwards, as 

 it is traced Southward. The next is a typical dolerite, whose 

 remains form a scarped edge, which presents a bold natural 

 precipice facing Westward, the familiar landmark known as 

 Salisbury Crags. Both of these may possibly represent 

 underground intrusions of basic eruptive matter, which are 

 possibly contemporaneous with the lavas of the same com- 



