Tlie Quartzose Conglomerate at Caldon Low, Staffs. 491 



hesitation in correlating the Caldon quartzose conglomerate with it, 

 and in assigning the whole series to the Cyathaxonia subzone Dg. 

 The same horizon is represented by the series of limestones in 

 the small quarries near Field House, north of Waterhouses.^ 

 In some of the beds here quartz pebbles and grains occur 

 associated with rolled and broken shells, pebbles of limestone, 

 fish-teeth, crinoid debris, and corals (several forms). Some of 

 the brachiopod shells and corals are beekized, and stand out 

 in relief on joint faces. We are .also of the opinion that the 

 greater part, if not the whole, of the series of limestones and 

 rolled shell-beds exposed in the quarries at Waterhouses belong 

 to the same horizon, viz. D3. The shell- and limestone-pebble 

 conglomerate is well seen in the disused quarry north of the station ; 

 it contains occasional quartz- pebbles. In this same quarry one of 

 the writers (J. W. J.) has collected a number of interesting corals, 

 including Michelinia glomerata, Favosites jmrasitica, and Alveolites 

 septosa. The absence of any record of the occurrence of the last- 

 named in the south-western district has been specially remarked 

 upon by Dr. Sibly.^ 



It is not without interest to note that there is strong evidence 

 of earth-movement and erosion in the eastern part of the Midland 

 area in late Dj times. In a section near Youlgreave, according to 

 Dr. Sibly,^ black shales of the Pendleside Series clearly overstepped 

 the truncated edges of limestone beds rejDresenting a high level in the 

 Lonsdalia subzone, D.^. " This section," Dr. Sibly points out, 

 ^' affords evidence of local earth-movement and erosion, conteni- 

 23oraneous with the deposition, in other parts of the area, of the 

 uppermost beds of the Carboniferous Limestone or the lowest beds 

 of the Pendleside Series." The Cyathaxonia Beds, Dg, are 

 absent here, and this may be due either to their removal by 

 denudation during early Pendleside time or to the locality having 

 formed land during Cyathaxonia time. Mr. C. B. Wedd ^ has also 

 described a similar example of local unconformity at Darley Dale. 

 It is not improbable that other examples will be found ultimately 

 in the Midland area. The formation of the rolled-shell and limestone- 

 pebble conglomerate (quartzose in part) referred to in this article 

 seems to us to have been the result of the earth-movement and 

 •erosion which produced the above-mentioned unconformities. 



Conclusions. — The Caldon quartzose conglomerate is a true 

 " Intraformational conglomerate," deposited in D., times. It fills 

 an erosion channel in beds of D.j age at Caldon, these beds, together 

 with the conglomerate, having been subsequently faulted down and 



^ These beds were assigned to D3 by Sibly in 1908. See Quart. Jonrn. 

 Oeol. Soc., vol. Ixiv, 1908, p. 61. 



2 Loc. cit., 1908, p. 48. 



^ Loc. cit., 1908, p. 63 and fig. 5 (p. 62). 



* Discussion of Dr. Sibly's paper, loc. cit., 1908, p. 81, and Mem. Geo!. 

 Surv. : " The Geology of the Northern Part of Derby Coalfield, etc.", London, 

 1913, p. 35. 



