510 A. C. KAMSAY AND J. GEtKIE ON 



the Windmill-Hill Flats, there are several faults which influence the 

 physical geography of the Rock, especially that part which lies 

 south of the Great Main Fault, which runs across the Rock from 

 sea to sea in the manner shown in the map (PL XXIII). This main 

 fault may be seen on the coast cliff a little south of No. III. Europa 

 AdvanceBattery, whence it trends through the Devil's Bellows and the 

 Naval Hospital to the sea near the New Mole Head. The proof is 

 as follows : — 



The shale overlying the limestone can be traced from the Case- 

 mate Barracks through the Town Range Barracks, and at the back 

 of the Upper Road Tank to a point on the Engineer Road a little 

 south-east of the Mount. There the continuity of this boundary is 

 interrupted by a short fault running north-north-east, which on 

 the westerly side of the fracture throws the shale directly against 

 the limestone north-west of Yiney Cottage Quarry. Two other 

 north-east faults at and near the Devil's Bellows and Windmill-Hill 

 Barracks throw in a rectangular mass of shale bounded on all sides 

 by limestone, only its northern edge being a natural boundary, 

 whilst all the rest are faults, one of which is the Great Main Fault 

 previously mentioned. 



South of this Great Main Fault, all the way to Europa Point, the 

 dips of the strata suddenly change their direction ; for between that 

 fault and the North Front the dip of the limestone is always west- 

 erly, as shown in the Sections I. to IV., excepting in a small area 

 between O'Hara's Tower and the fault, where the beds stand 

 vertically. Between the main fault, however, and Europa Point 

 the dips of the limestone are very nearly east, as may be seen on 

 the Devil's Bowling Green, on Windmill-Hill and Europa Flats, 

 and all round the coast cliffs from Camp Bay by Europa Point to 

 the Great Main Fault, where it passes under the Mediterranean Sea. 

 The angles vary from 25° to 65°, as shown on the map and Sections 

 Nos. V., VI., and VII. 



It appears to us that, south of the fault, the forces that disturbed 

 the strata have in this area been sufficient to turn the limestone 

 fairly over with a reversed dip, so that the uppermost beds as 

 originally deposited now dip underneath strata that originally lay 

 below them. 



This view seems to be confirmed by the occurrence of two small 

 patches of shale at Camp Bay and Little Bay, which dip eastward 

 under the limestone, and are thrown against it on the north by two 

 faults, each of which is a downthrow on the south. 



The structure of the southern end of the Rock is shown in the 

 Sections Nos. V., VI., and VII. 



In Section No. V., south of O'Hara's Tower and near Monkey's 

 Cave, the beds of limestone are shown standing vertically ; next 

 comes, at Windmill-Hill Barracks, the faulted rectangular patch of 

 shale already mentioned, west of which, as far as Camp Bay, the 

 limestone dips east about 45°, and is, to a great extent, overlain by 

 the limestone-agglomerate, so well seen in the rugged gorges or dry 

 gullies that traverse the Rock between Camp Bay and Europa Pass. 





