ABSTRACT OF PROCEEDINGS. XXXV11. 



tion of Woodford in an easterly and north-easterly direction. 

 Such a view shows that the even easterly slope of the 

 plateau is interrupted by abruptly rising ground just west 

 of Kurrajong Heights. This sudden rise in the plateau 

 extends for a considerable distance to the north and south 

 of that locality. Traced in a southerly direction across 

 the Grose Valley to Glenbrook Railway Station, the fault 

 to which this Westerly escarpment is due, almost, if not 

 altogether, dies out passing into a gentle westerly fold, 

 which at Glenbrook does not appear to have been accom- 

 panied by shearing. To the east of Glenbrook Railway 

 Station is the well known steep easterly monocline, 

 referred to by the late Government Geologist, Mr. C. S. 

 Wilkinson, which there forms the Eastern escarpment of 

 the Blue Mountains, known as Lapstone Hill. Traced 

 northerly from Lapstone Hill the moncline crosses Grose 

 Valley and forms the eastern slope of Kurrajong Heights. 

 The top of the monocline at Kurrajong Heights is over 1900 

 feet above sea level, and the top of the fold is about 1100 

 feet above the bottom of the fold, whereas at Glenbrook 

 the top of the fold is only about 600 feet above the bottom 

 of the fold. This seems to show that the movement of the 

 earth's crust has been more extensive at the Kurrajong 

 than at Glenbrook. This may account for the fact that 

 the monocline at the Kurrajong is bounded westwards by an 

 abrupt fault, whereas at Glenbrook the line of disturbance 

 takes the form of a gentle fold facing the west. The Kur- 

 rajong fault has a throw to the west of 300 feet. The 

 fault plane though somewhat eroded still forms a steep 

 and very conspicuous escarpment. The Wianamatta shales 

 on the downthrow side of the fault extend for a consider- 

 able distance towards Mount Tomah along the watershed 

 separating the Grose Valley from the Colo Valley, and 

 known as Bell's Line. The effect of this fault in displacing 



