W. Keeping — Geology of Cardigan Town. 521 



perfect slates, and irregular shaly slates, of ratlier dark bluish colour, 

 only varied by the occurrence, here and there, of lines of cone-in-cone 

 nodules and thin bands of grit. 



In all this stretch of country I find no break in the rock series. 

 It is a great slate country, there being, indeed, no grit bed of 

 sufficient development to serve for such local purposes as rough 

 building or road-mending. All hard 'road metal' is obtained either 

 from the boulders of Felsite, Greenstone, Grits, etc., scattered over the 

 surface, or from some beds of sandstone higher up in the series, 

 which we proceed to notice. The sandstones are well seen in 

 quarries on the top of the cliif, some half-mile north of Penbryn ; in 

 a wood near Morfa Ganol ; and, further east, in a road quarry at 

 Llain. They form a compact series of thich grit beds, some twenty 

 feet in all, pale-coloured and sharp-jointed. Some of the beds show 

 a well-marked development of coarse tortuous prominences upon 

 their under surfaces ; and one bed near the centre of the series is 

 broken up into coarse rubbish by lines of concretionary structure. 



The rock is a finely granular sandstone crowded with fragments 

 of felspar, and with some small black grains and crystals ; colours 

 pale blue grey to greenish yellow weathering to fox yellow. In 

 the cliff quarry the rock is darker and less felspathic. 



The stratigraphical position of this grit zone is in the upper 

 part of the imjDerfect shaly slate series above described. It lies 

 conformably in that series, and does not appear to mark out any 

 geological break ; lithologically the rock agrees very closely with 

 the sandstones of Cardigan Harbour. Above this we again find, 

 in Dogskin Bay, a dark imperfect slate series and dark leaden 

 blue rab, in which concretions of grey grit begin to appear ; then 

 thin beds of concretionary grit gradually come in and develope, until 

 in Fraethbach and at Llangrannog we find ourselves upon the un- 

 doubted Aberystwyth grit series, very well developed. The grits 

 are of the regular concretionary mid-Wales type, with contorted 

 structure and strange volutions, and other prominences upon their 

 under surfaces, while all the associated argillaceous beds present 

 all the forms of rab, shale, and pencil rab, such as we find at 

 Alltwen, Aberystwyth. Still, a conspicuous difference of general 

 character is produced by a want of the regular thicknesses and 

 orderly alternations of the beds of grit and shale as found further 

 North. For here, indeed, we have the gradual tailing off of the 

 grit series as it dies away to the South. In this district the section 

 at Fraethbach must be noticed for its wonderful developments of 

 concretionary grit structures, which I hope to describe elseAvhere. 

 At Llangrannog the Aberystwyth grits are very well developed. 

 They dip inland, to the east, and, a little above the church, are seen 

 passing conformably under a series of imperfect slates and flags, 

 with fucoidal and worm markings upon their surface. The easterly 

 dip holds pretty steadily on towards Pigeonsford and along the 

 hill- sides south of Llangrannog valley, where pale shaly slates 

 and hard slate rock, belonging to our Metalliferous group, are 

 uniformly developed. 



