Geological Society of London. 373: 



scale has taken place. This structure attains its widest development 

 on tlie north side of the central valley, though it is noted on a more 

 limited scale in a few localities farther south. It is well exposed in 

 the cliffs three miles north of Peel, but the finest sections are in the 

 interior in Sulby Glen, where the structure has a thickness of some 

 hundreds of feet, and runs continuously about north-north-east for 

 five miles, with a probable extension southward for three miles 

 farther, and also eastward for other four miles. It is usually 

 flanked by gritty flags on one side, and by dark clay-slates on 

 the other. It is affected by a strain-slip cleavage later than the 

 brecciation, and several igneous dykes which intersect it are affected 

 by the same cleavage, though not by the brecciation-movement. 



East of Sulby Glen the structure extends towards Ramsey, at 

 first in a horizontal spread over a mile in width, and afterwards 

 in a series of comparatively narrow subparallel bands; and it is 

 suggested that we are dealing here with the emergence of a deformed 

 plane. The structure is continued eastwai'd into the hill overlooking 

 Earasey, beyond which it is cut off by the sea. In this locality, as 

 elsewhere, the sections show the gradual smashing into fragments 

 of highly contorted strata until every trace of the original bedding 

 is lost, and a " crush-conglomerate " with lenticular and partly 

 rounded inclusions is formed. 



The rocks described in Mr. Watts' Appendix are grouped in four 

 classes. Firstly, the grits and slates which have been crushed 

 but have not been converted into crush-conglomerates ; secondly, 

 the crush-conglomerates themselves, and the fragments which they 

 contain ; thirdly, the dykes of decomposed dolerite (greenstone) and 

 fresh later dolerite which penetrate the conglomerate ; fourthly, 

 a portion of the crush-conglomerate metamorphosed by these in- 

 trusions. 



The chief point of interest is brought out by the examination of 

 the fragments in the conglomerate. All stages of crushing may be 

 traced, until the grit- fragments have a structure which is a mere 

 miniature of the crush-conglomerate itself; that is to say, if the 

 crush-conglomerate be regarded as made of " fragments " of hard 

 rocks enclosed in crushed "matrix" of soft rocks, a host of inter- 

 mediate varieties with varying resistances will occur. Whether any 

 particular one of these varieties shall pass into " fragments " or 

 "matrix" under the crushing will depend upon the amount of the 

 crushing force and upon the association (paragenesis) of the material 

 brought together to be crushed. 



3. " The Chalky Clay of the Fenland and its Borders : its Con- 

 stitution, Origin, Distribution, and Age." By Sir Henry H. 

 Howorth, K.C.I.E., M.P., F.R.S., F.G.S. 



The distribution of the Clny (so often termed Chalky BonJder-c\ay) 

 is noticed, and it is stated that it is surrounded on all sides by 

 country occupied by different deposits, being mainly separated from 

 the sea on the east and north-east by sandy and pebbly materials, 

 while on every other side it is clearly and sharply defined. The 

 paucity of foreign stones is noted as compared with natives, and 



