Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/535

1869.] MACKINTOSH—LANCASHIRE AND CUMBERLAND DRIFTS. 411 c. Eagberg "Rockery." —In the Eagberg cliffs, north of Uncle Tom's Cabin, both the laminated sand and pebble-beds have here and there become consolidated into rock as hard as some kinds of millstone-grit*. Owing to the formation of rain-ruts on each side and the washing away of the looser matter underneath, fragments of the sandstone or conglomerate become undermined and fall down. In their descent they either reach the beach or become entangled in the facing or talus of fallen clay. In the latter case they project from a temporary matrix of soft or loose matter, in which they are believed by the country people to have grown. The harder laminae of sand and layers of pebbles project beyond the softer parts, giving rise to fantastic shapes. In their merely fallen state they are, I believe, of comparatively little value; but when they are reached by spring tides, and smoothly rounded by the waves, they are highly prized as ornaments to enclosures in front of houses &c. They sometimes resemble certain styles of architecture, the gothic arch and window included, and often mimic the table and smith's anvil. They are believed to become harder by exposure to the sun. About half a mile (some say a greater distance) from the present cliff-line a very large split block, called Pennystone, may be seen, at the lowest- water mark. It is a mass of consolidated middle drift, much too large, it is believed, for the sea to displace. It is supposed to lie in the spot where it fell from the then-existing sea-cliff, and is looked upon as an evidence of the removal of half a mile of Eagberg hill by the gradually encroaching sea since the days of Edward II. Near it there is a smaller stone called the Carlin or Witch-stone; and both stones are referred to in the following traditional couplet:—

Penny stood, Carlin fled, Red bank ran away†.

Except during exceptionally high tides, the sea does not now encroach on the "Red bank."

d. Lower Boulder-clay and Loam.—I have traced this formation under high-water level from a point nearly half a mile south of the New Pier to more than half a mile beyond Uncle Tom's Cabin. In most places it is temporarily, in some places perhaps permanently covered with recent sand and shingle; but it exhibits larger or smaller areas which at any time may be seen swept clean of all loose materials. Near the coast, where its surface slopes a little seaward, it resembles a hard artificial concrete pavement. Further out at sea, and at a lower level, its character is varied. The following notes

observed hard blocks of consolidated sand and gravel occurring at a certain level though not in a connected band, in the drift intervening between the chalk and (Upper) Boulder-clay of the high ground of Suffolk (Quart. Journ. Geol. Soc. Jan. 23, 1867). This consolidated sand and gravel is probably of the same age with that at Blackpool.
 * It is interesting in connexion with this fact to notice that Mr. G. Maw has

† For this information I am indebted to the Rev. Mr. Thornber, of Blackpool, a well-informed antiquarian. Red bank signifies the drift-cliff reddened by the facing of Upper Boulder-clay, which is continually falling down and obscuring both the middle sand and gravel and Lower Boulder-clay.

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