The striking headland of the Great Orme as well as Little Orme's Head
is composed of carboniferous limestone, containing corals and large
_Productus_ shells. A narrow strip of the same formation runs along
the Menai Straits for several miles south of the tubular bridge. At
the southern extremity of the limestone a small patch of coal measures
is found.

Glacial drift--gravel, boulders and clay--is abundant along the
northern coast, and in the neighbourhood of Snowdon it is an important
feature in the landscape; massive moraines, perched blocks, striated
stones and other evidences of ice action are common. On Moel Trygarn
and on the western flanks of Snowdon marine shells have been found in
the drift up to an elevation of 1400 ft. above sea-level. Blown sand
occurs along the coast near Conway, south-west of Carnarvon and on the
south coast. Several hollows and pipes in the carboniferous limestone
about Orme's Head contain clays and sands of mixed origin, including
Upper Carboniferous, Triassic and drift materials. The igneous rocks,
especially those of volcanic origin, constitute one of the most
striking geological features of the county; they comprise felsites,
rhyolites, quartz porphyries, enstatite diabases, andesite tuffs,
diabases and granite.

The climate is cold and damp in winter, except in the peninsula, Lleyn,
and on the mild coast. Arable land, but a small proportion of the
surface, is mostly in the Conwy valley or near the sea. Principal crops
are oats, barley and potatoes, with some little wheat. The valley soil
(alluvial) is often fertile, chiefly as meadow and enclosed pasture.
Dairy and sheep-farming occupy most farmers. The small mountain ponies,
especially of Llanbedr (Conwy Vale), are famous, and Welsh ponies were
known for staying power even to Arrian (_Cynegetics_). Agriculture still
too much follows the old routine, besides losing by the influx of labour
into the towns or to the mining industry and "set works" (stone).

The county is served by the London & North-Western railway; its terminus
is Afon Wen, within 4 m. of Pwllheli. Between these stations plies the
Cambrian, which runs along the Cardigan Bay coast and terminates at
Pwllheli. The North Wales Narrow Gauge line runs from Dinas, south of
Carnarvon, to Snowdon Ranger, 4 m. from Beddgelert. The main line of the
London & North-Western runs along the northern coast, with branches from
Llandudno junct