376 



NOLTON CULM MEASURES. — SLASHES OR 



ft. in. 



a. Overlying sandstone and shale, thickness variable 



1. Fourth back, a thin coal seam 1 6 



b. Measures, consisting of flags, sandstone and shale 



2. Cliff vein . 3 6 



c. Measures.. . 



3. Small coal vein 1 4 



d. Hard sandstone and measures 



4. Foot vein i 1 0 



e. Measures of various sorts, 46 fathoms thick, separate the foot coal from the 4 foot as proved 



by shafts (ascertained by working the foot and 4 foot veins in the same shaft) 



5. Four foot vein — .... 4 0 



/. Measures » 



6. Little engine vein , - 2 0 



g. Measures • 



7. Green vein, ocasionally expanding to 8 and 9 feet, very irregular 2 0 



h. Measures 



8. Pit vein, irregular and lumpy, varying from 2 to 9 feet 2 0 



i. Measures, including the headstone rock (sandstone) 



9. Tom Rees's vein 1 6 



j. Measures 



10. Smith's coal vein 1 4 



The produce of the " Smith's coal vein " is alone adequate to forging iron, and is the lowest seam 

 worked, though other thin and imperfect beds occur in the underlying flagstones and shale. All 

 these beds, to the north of Nolton, dip to the west or a little north and south of west, according to 

 the flexure to which the whole are subjected, as marked in the map. The coal seams, having a re- 

 gular sweep for nearly two miles, are cut off on the north by a great dislocation which throws the 

 coal strata into an arched position, transverse to the direction of those of Nolton. On the south 

 side of this dislocation the cliff vein No. 2, terminates in what the miners here call a i( slough," 

 (see wood-cut p. 377-)j *• e -> ft 1S Den ^ suddenly downwards, accompanied on each side by the usual 

 measures. The downward termination of this " slough " has never been ascertained, but if it were 

 worth the outlay to sink into it, the vertical position most probably would soon be found to bend 

 in some other direction, like many of the contorted strata of this coast. 



Slashes of Culm. — Besides Si sloughs" there occur in Broadhaven and elsewhere, small but very 

 deep troughs of finely fractured culm, which are called "slashes." These (as far as my knowledge 

 goes) are peculiar to Pembrokeshire. In one of the principal of these "slashes" at Broadhaven, 

 belonging to Mr. Leach, there is no trace of bedding or of associated sandstone and flagstone, 

 but the miner after penetrating a little shale, works through a confused mass, made up entirely 

 of small fractured culm which has been proved in this spot to a depth of 16 to 17 fathoms. 

 The sides and bottom, as far as they have been examined, seem to show that the culm lies in a 

 trough, but a band of hard sandstone rising "en dome," runs through the middle of it. Again, 

 if we examine the coast sections between Broad Haven and Little Haven where the strata are 

 exceedingly contorted, we even find small patches of culm, often highly comminuted, occurring at 

 intervals between the convoluted beds. 



In accounting for these extraordinary accumulations of broken coal we may un- 

 doubtedly refer their origin to the wreck of the regular seams ; and infer, that during 



