138 GEOLOGY OF ALDERNEY* 



l,ooo yards in length, the narrowest part of the Island. 

 Evidence of this fault is found in Roche's Quarry and the 

 smali quarry north of it, where there is E.W. faulting. The 

 northern quarry shows a slight hade to south. Ihese two 

 faults appear to converge at the iNunnery. With the main 

 northern tault already mentioned they provide a rift fault 

 from Braye Bay to Longy Bay, isolating the north-eastern 

 grits. This latest fault is in consonance with the general 

 trend of Armoncan movement, perhaps us latest expression 

 in Alderney. The faulting in the grits which it cuts off 

 seems the earliest evidence of Armoncan folding. 



On a large scale the prevailing S.E. dip ot the less dis- 

 turbed eastern grits, and the prevailing N.N.E. and N.E. 

 dip of the Jersey Conglomerate, provide synclinal folding 

 with an E.-VV. axis, pitching to the east. 



The writer acknowledges indebtedness to the Govern- 

 ment Grant Committee of the Royal Society which enabled 

 the work detailed here to be undertaken; and to Mr. and Mrs. 

 A. J. Robinson, Mr. G. D. Bond and Mr. A. J. Mayes, for 

 their helpfulness in field work and photography. 



Bibliography. 



1811. J. Mac Culloch. Account of Guernsey and the other 

 Channel Isles. Trans. Geol. Soc, vol. 1, ser. 1, p. 1. 



1862. Ansted & Latham. The Channel Islands. 



1877. Prof. Liveing. On the Metamorphism of the Rocks 

 of the Channel Islands. Proc. Camb. Phil. Soc, 

 3 P. 75- 



1888. Prof. A. Bigot. Observations Geologiques sur les lies 

 Anglo-Normandes. Bull. Soc. Geol. Fr. 3 ser., tome 

 xii., p. 284. 



1889. Rev. E. Hill. On the Rocks of Alderney and the 

 Casquets. Quart. Journ. Geol. Soc, p. 387. 



1890-1892. Prof. A. Bigot. Basse Normandie. Bull. Lab. 



Geol. de la Faculte des Sciences de Caen. 

 191 2. Prof. T. G. Bonney and Rev. E. Hill. Petrological 



Notes on Guernsey, Herm, Sark, and Alderney. 



Quart. Journ. Geol. Soc, Feb. p. 53. 



1916. T. Parkinson. The Channel Islands. Handbuch der 

 Regionalen Geologic. III. Band. I. Abteilung p. 334. 



