128 ROYAL SOCIETY OF CANADA 
siliceous earths, with clays of various colours, and a considerable thick- 
ness of voleanic mud. ‘The last is evidently of foreign origin since there 
is no trace of voleanic rocks anywhere on the island. 
The siliceous or Radiolarian earths are of interest and in general 
character closely resemble the infusorial earths found in New Brunswick 
and Nova Scotia. The microscopic examination, however, shows that 
their origin is distinct, in the fact that the diatoms in the Barbados earths 
present features connecting them with those obtained from deep-sea 
dredgings, instead of fresh water forms as is the case with most deposits 
of this nature. They sometimes form beds with a thickness of nearly 
100 feet which have been laid down subsequent to the movements which 
have caused the plications in the underlying Tertiary rocks. Under 
certain conditions these should form a material of considerable economic 
importance. 
The Tertiary formation which occupies the remaining seventh of 
the area embraced in this island on the eastern coast have been exposed 
by the denudation of the coral and oceanic formations. It presents 
the usual series of soft shales of various colours associated with beds of 
soft greyish and dark coloured oil-bearing sandstone. As a formation 
the rocks are greatly disturbed, faults and folds being more strongly 
marked than in Trinidad, though the general character of the rocks is 
very similar. In places the anticiines are fairly regular, but sometimes 
the angle of inclination reaches the vertical and occasionally the folds 
are completely overturned. The exposed thickness of this formation is 
difficult to ascertain owing to its broken and folded character, though an 
estimate by the Geological Survey of the island gives approximate figures 
of 560 to 600 feet. 
The surface of these districts as viewed from the summit of the island, 
looking eastward, presents an exceedingly rough aspect. It has been 
deeply furrowed by atmospheric agencies and cut into great gullies 
extending nearly to the sea shore in places, and in its often ragged 
character it somewhat resembles the deeply furrowed side gullies seen in 
certain of the river valleys of British Columbia where the rocks are of 
similar horizon. 
In the report of Harrison and Jukes Brown, published in 1890, the 
general resemblance of the Tertiary sediments to those of southern 
Trinidad was pointed out. They are there distinguished in 
Barbados under the name of “Scotland series” and are regarded 
as constituting the oldest formations known on the island. Like 
the Trinidad Tertiary they contain petroleum which has been 
found in.considerable quantity at several points by borings which 
have been carried on for some years. The oil in places is found 
