252 EXCURSION TO FROGHALL, CALDON LOW, AND ALTON. 
As the afternoon was advancing we left Caldon Low, and with it our 
estimable cicerone, Mr. Fraser, whose courtesy, information, and arrange- 
ments left nothing to be desired, and striking across the country to the 
south-east, presently descended into the embouchure of a ravine in the 
limestone, with the slopes of Wardlow rising to above 1,000ft. on the left 
and a much lower ridge on the right. Our path was dotted on either 
side by old clay pits about 20ft. deep. These showed that the bottom of 
this valley was filled with deposits of white clay, covered with a thick 
deposit of red Drift sandand pebbles. The water at the bottom of the pits, 
however, prevented any examination of their steep sides; and there was 
no halt till we got to the Ribdin pit, about a mile south of Caldon Low. 
Here was a very extensive opening, about 40ft. deep, in the white clay 
deposits, forming the western slope of the valley, where it had widened 
out somewhat. The section revealed about 30ft. of white and yellow 
fine tough clay, with irregular patches and broad bands of well rounded 
quartz pebbles, and large angular blocks of Millstone Grit, Lower Keuper 
pebbly sandstone, and occasional rounded boulders of chert. Neither 
contortion nor bedding could be made out; but irregular masses of 
yellow clay or pink sandy clay reared themselves up in the midst of 
white clay in the most perplexing manner; yet the deposits had 
evidently been very slowly accumulated, and were capped with a thick 
deposit of Drift. Many of the blocks embedded in the clay had so far 
decomposed as to preserve only their original outline and sandy texture, 
but were as soft as the clayey matrix; others had altogether melted 
into the clay and given ita pink tint. Curiously enough there were no 
traces of limestone among the débris. These argillaceous deposits are 
said to extend more or less over a stretch of nearly two miles from north- 
west to south-east, but the rock on which they rest could not be seen, 
though it is mapped as Carboniferous Limestone. They occupy a position 
about 1,000ft. above the sea. Similar deposits have been met with in 
North Wales and in Tipperary, at heights of from 800ft. to 1,000ft., mostly 
in deep cavities in the Carboniferous Limestone, and always below the 
Drift. They may not all be of the same age, but in nearly every case 
the same mineral characters are found associated—soft chert breccias, 
white and buff clays, dark laminated clays, and carbonaceous beds. 
The cavities in which these deposits occur appear to have been formed 
after the manner of sand pipes in the Chalk—hby the slow dissolution of 
the limestone, into which the superincumbent beds of grit or sandstone 
appear to have gradually subsided. 
It was difficult to tear ourselves away from so interesting a spot, 
for there was sufficient here alone to furnish a good day’s work. Regain- 
ing the main road, however, near Three Lows, we kept the ridge of 
Yoredale, capped at intervals by Millstone Grit, on to Farley. The 
scenery was exceedingly pretty all the way, but as we descended into the 
valley of the Churnet, at Alton, it became magnificent. It was now too 
late to examine any of the fine exposures of the Lower Keuper at Alton, 
so that a very agreeable lunch at the “Shrewsbury” terminated a 
capital day’s labours. 
_— 7" 
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