Rev. R. Ashington Bullen—MHolian Deposits at Htel. 99 
birefringence shows that the green tint is not due to chloritization : 
inclusions with slight pleochroic halos are found. Accessory and 
secondary constituents (other than kaolin) are uncommon, a little 
granular epidote being alone noteworthy: this is associated with, and 
presumably derived from, decomposed felspars. This rock is a ‘ granite- 
proper’ or ‘two-mica granite’, the ‘muscovite-granite’ of some 
authors, a ‘ granulite’ in the French sense. 
§ 2. The granulite, or muscovite-biotite granite, outcrop can be 
seen in Fig. 1 (Plate IX). The point thus formed is the Cap de Garde 
at the mouth of the Riviére d’Ktel, looking across westward from the 
left bank, at about half-flood tide. I find that the tower (La Tourelle) 
does not stand actually on the rock called Le Chaudronnier ; the latter 
is seen surrounded by water a little behind and westward, and is 
indicated by the white arrow pointing from above it. Consequently 
my former remarks must be modified to this extent, other statements 
of fact, however, remaining unaltered. 
It was in the ‘baylet’ just westward of the granulite that. the 
masses of rolled peat occurred.'. As the prevailing winds are from 
the south-westward, and as strong currents seem to set from westward, 
the source of the submerged peat beds may possibly be to the west- 
ward too. The prevailing current is said to originate in the region 
of westerly winds in the Atlantic, and to flow along the north coast of 
Spain and up the west coast of France to the north-westward, but it 
is much influenced by the prevailing wind and the tidal currents. 
The only submerged peat beds that have been described in Brittany 
lie on the north coast at Plougasnel-Primel, near Morlaix (Finistére). 
The deposit measures roughly 7 ft. 6 in. in thickness, and contains four 
well-defined vegetable layers, the upper containing stools of trees 
(beech, holly, and hazel). There are two well-marked peat beds, the 
upper being ‘40 metre and the lower ‘55 metre in thickness (see 
L. Cayeux, Bibliography, al jfin.). M. Jos. Bourlot also mentions 
a submerge forest (elm) at Pointe du Raz, and suggests others round 
the Bay of Douarnénez (see J. Bourlot, Bibliography, a/ fin.). 
The lines of white quartz pebbles on the left bank are most probably 
derived from old Raised Beaches of Pleistocene age (now obliterated, 
except fragmentarily), just as the pebbles of the Chesil Beach, in 
Dorset, have been derived from beaches of the same age in England.? 
Fig. 2 (Plate [X) shows the cliff (falaise) on the left bank, marked 
Y, --- yy, In the plan. The place from which the ‘granulite’ 
was procured for the microscope is marked with a white x. The 
capping of the cliffs is of blown-sand, with grains of quartz and 
brown and white mica, and contains much finely broken debris of 
Bittium reticulatum, as well as many entire shells of the same 
abundant species. The sand here is of a brown colour, most probably 
due to this fact. This is the finest outcrop of ‘granulite’ between 
Ktel and the sea. Bolder cliffs occur, however, at Pont Lorois, about 
' Grou. Mae., No. 547, January, 1910, p. 8. 
2 Prestwich, Geology, vol. i, p. 99. Minutes of Proceedings of the Institute of 
Civil Engineers, vol. xi, pt. ii, p.4. For summary see Damon, Geology of Weymouth, 
p. 174. 
