42 Reports and Proceedings — Geological Society of London. 



coast nearly corresponds witli a pre-Glacial chalk-cliff against whicli 

 the Drift was deposited. 



In the Jasmund district the authors lay special emphasis on three 

 points: — (1) The 'inliers' of Drift appear to occupy valleys 

 excavated in the Chalk ; (2) these valleys can be traced for some 

 distance inland; (3) the steep walls of Chalk towards which the 

 Drift dips sharply, and against which it ends abruptly (usually OU' 

 the southern side), often trend gradually inland, as if the present 

 coastline had passed obliquelj'^ across an old valley. In one or 

 two instances the Drift is slightly twisted up against this steep 

 face of Chalk. The authors call attention to cases where the Drift 

 clearly rests against old surfaces and cliffs of Chalk ; and to one in 

 particular, which was not visible in 1898, where (o) clay, (h) sand,. 

 and (c) clay occupy a shallow valley, and have assumed a synclinal 

 form. The authors give reasons to show that neither solution of 

 the Chalk, nor ice-thrust, nor folding, nor even faulting, can 

 satisfactorily explain the peculiar relations of the Drift and Chalk 

 in Eiigen ; and they can find no better explanation than that offered^ 

 in their previous paper. 



2. " On certain Altered Eocks from near Bastogne and their 

 Eelations to others in the District." By Catherine A. Eaisin, D.Sc. 

 (Communicated by Professor T. G. Bonney, D.Sc, LL.D., F.E.S.^ 

 F.G.S.) 



Professor Eenard, from the petrographical study of specimens, 

 and Professor Gosselet, after description of the district and its- 

 stratigraphy, have attributed the changes in these rocks to 

 mechanical disturbances. Dumont had previouslj'^ described many 

 examples and inclined to the view of contact-alteration, which was 

 favoured by Von Lasaulx's discovery of a granite in the Hohe Venn 

 and M. Dupont's identification of chiastolite from Libramont. 



The present paper treats especially of the garnetiferous and 

 hornblendic rocks, giving the full petrographical and field details 

 of a few examples. It points out that the eflects of pressure are- 

 evident over the whole district, while mineral modifications 

 resembling the results of slight contact-action are found in certain 

 areas. In a few cases these modifications are more marked, and 

 sometimes increase as we approach veins composed of quartz, 

 felspar, and mica, such as might be connected with a concealed- 

 granite. 



The peculiar garnetiferous and hornblendic rocks, although 

 occurring within the zone of alteration, are extremely limited, 

 often forming patches or bands a few feet across. Thej'^ diff'er, as 

 described in the paper, from ordinary contact-altered rocks. The- 

 evidence, in the authoress's opinion, is in favour of Prof. Bonney's 

 suggestion that they are due to some form of hot-spring action. 



II.— Nov. 21, 1900.— J. J. H. Teall, Esq., M.A., F.E.S., President, 

 in the Chair. The following communications were read : — 

 1. " A Monchiqnite from Mount Girnar, Junagarh (Kathiawar)." 

 By John William Evans, D.Sc, LL.B., F.G.S. 



