CHAP. -XIK 
MONTROSE CENTRE OF ERUPTION 
301 
Stratified through its iutricate ramifications among the pile of dark 
clinkers. 
The seaward inclination of the rocks allows the succession of lavas to 
be seen as the coast is followed westward into Liiiian Bay. On the furthei 
side of that inlet, after passing over a group of sandstones that underlie 
the volcanic series of the Bed Head, the observer meets with a second and 
lower succession of lavas which in the five miles northward to IMontrose 
Harbour are admirably exposed both along coast-cliffs and on the beach. 
They resemble those of the Bed Head, being made up of alternations of highly 
vesicular andesite with more compact varieties, and showing similar sand- 
stone veinings. Here and there, as at Bishtown of Usar, the sea has cut them 
down into a platform from which the harder parts rise as fantastic hall-tide 
stacks. In some cases, the more durable rock consists of the slaggy upper 
portions of the Hows, and in one case this material stands up as a rude 
pillar twelve feet high, composed of clinkers firmly cemented with veinings 
of sandstone. The geologist who wanders over this coast-line is arrested at 
every turn by the marvellously fresh volcanic aspect of many of the lavas. 
Their upper parts are so cellular that if the calcite, chalcedony and other 
infiltrated minerals were removed from their vesicles, they would be trans- 
formed into surfaces of mere slag. In one respect would their antiquity 
still be evident. These slaggy bands are generally a good deal reddened, as 
if they had been long exposed to oxidation before being covered by the 
overlying sheets of lava — a feature already cited, as probably indicating the 
lapse of some considerable interval of time between successive outflows. 
Alone' this coast -section the absence of intercalated tuffs is soon re- 
marked. The volcanic ejections seem to have consisted almost entirely 
of andesitic lavas, though it is possible that here and there the very 
slaggy bands between the more solid parts of the sheets may include a 
little pyroclastic material. The lowest portion of the volcanic group here 
visible is reached at Montrose Harbour, where, in the flagstones and shales 
of Ferryden, the late Bev. Hugh Mitchell obtained some of the fossil-fishes 
of the formation. 
A space of more than three miles now intervenes where the rocks are 
concealed by blown sand and other superficial accumulations. It is through 
this hollow, as already stated, that the great Ochil anticline runs out to sea. 
On the north side of the North Esk Biver, we again come upon the same 
band of lavas as to the south of Montrose, but with a dip to the north-west. 
This inclination, however, soon bends round more westerly, and the result 
of the change is to expose a slowly descending section all the way to the 
Highland fault at Stonehaven. 
A picturesque line of high inland cliff, running northwards beyond St. 
Cyrus, reveals with great clearness the bedded structure of the andesites. 
But as one moves northward, owing to the change in the direction of dip, 
one finallv passes out of this volcanic belt and begins gradually to descend 
into the thick Kincardineshire Old Bed Sandstone. The amount of con- 
glomerate exposed along this part of the coast-line probably considerably 
