Towy, of which
little is known, is made up of a monotonous succession of greatly
folded slates and shales with interbedded conglomerates and sandstones
which give rise to scarps, ridges and moorlands; they appear to be of
Llandovery age.

South of the Towy a narrow belt of steeply dipping and even inverted
Silurian sandstones and mudstones (Upper Llandovery, Wenlock and
Ludlow) extends south-westwards from Llandovery to Llanarthney, where
they disappear under the Old Red Sandstone. This formation, which
consists of red marls and sandstones with occasional thin impure
limestones (cornstones), extends from near Llandovery to beyond
Carmarthen Bay; its upper conglomeratic beds cap the escarpment of the
Black Mountains (2460 ft.) on the south-eastern borders of the county.
To the south the scarps and moorlands of the Carboniferous Limestone
and Millstone Grit form the north-western rim of the South Wales
coalfield. The rest of the county is occupied by the rich
Coal-Measures of the Gwendraeth Valley and Llanelly districts. All the
rocks in the county are affected by powerful folds and faults. Glacial
deposits are plentiful in the valleys south of the Towy, striae abound
on the Millstone Grit and show that the ice-sheet rose far up the
slopes of the Black Mountains. Coal is the chief mineral, the iron-ore
is no longer worked; the Carboniferous Limestone is burnt at
Llandybie; fire-bricks are manufactured from the Millstone Grit, and a
few lead-veins are found in the Ordovician rocks.

_Industries._--The climate is mild, except in the upland regions, but
the annual rainfall is very heavy. With the exception of its
south-eastern portion, which forms part of the great South Welsh
coalfield, Carmarthenshire may be considered wholly as an agricultural
county. The attention of the farmers is devoted to stock-raising and
dairy-farming rather than to the growth of cereals, whilst the large
tracts of unenclosed hill-country form good pastures for sheep and
ponies. The soil varies much, but in the lower valleys of the Towy and
Taf it is exceedingly fertile. Outside agriculture the gathering of
cockles at the estuaries of the Towy and Taf gives employment to a large
number of persons, principally women; Ferryside and Laugharne being the
chief centres of the cockling industry. The local textile factories at
Pencader, Penboyr, Llangeler, and in the valley of the Loughor are of
some importa