LOWER LIAS : ABERTHAW. 
117 
separated, then simply bent, and finally no appearance of dis- 
turbance was visible. (See Fig 48.) I have seen similar faults 
in the Purbeck Beds near Swanage. They appear to be due to 
irregular compression of the beds, and not to the effects of 
landslips. 
FIG. 48. 
Section of Lower Lias, east of Dunraven Castle, Glamorgan- 
shire. 
Immediately east and west of 
St. Donat's Point, the beds are 
somewhat faulted and tumbled. 
There is however no great 
o 
displacement, and the ledges 
display Gryphcsa arcuata, Lima 
giyantea, Ammonites Bucklandi, 
and lignite. From the higher 
beds I obtained Am. Conybcarei. 
There is a considerable accu- 
mulation of coarse boulder- 
shingle here, and large blocks 
are taken away for building- 
purposes, and occasionally to be 
burnt for lime. Some of the 
beds exhibit fucoidal markings. 
The beds south of Llantwit-Major are much jointed ; in fact 
the beds showing rhomboidal jointing come down to the beach, 
and the blocks are worked off by the sea in huge masses. These 
are readily broken up and rounded, so that the ledges of rock are 
in many places irregularly covered by accumulations of boulder- 
shingle. From Llantwit to Stout Point the beds are tolerably 
level and unbroken the highest part of the cliffs being 146 feet. 
There is a slight seaward dip, and this continues towards Sum- 
merhouse Point, and has produced cliffs that overhang in places. 
A short distance east of the Camp, the cliff ends, the last beds 
seen here being 8 or 10 feet of jointed limestones and clays. 
From a short distance east of Summerhouse Point to the east 
of the River Daw, at East A berthaw, there are no cliffs, the coast 
being bordered by Alluvial flats, hillocks of Blown Sand and a 
high beach of boulder-shingle. It is this ehingle, composed of 
rolled limestone derived from the cliffs further west, that has 
furnished and still furnishes the celebrated Aberthaw lime. All 
the ' lime " shipped, goes away in the form of pebbles (3 or 4 
inches in diameter), and those are reckoned the best that are 
taken between high- and low-water mark, where washed by the 
sea. The trade has of late years considerably declined, in fact, 
since the introduction of railways, the lime from places inland 
has come more and more into use : but I was informed that 50 
or 60 years ago (1827-1837) there were sometimes twenty vessels 
in the "Port," that had come to take away the stone for lime. 
