Speight. — The Tertiary Beds of the Trelissick Basin. 329 



The following beds occur in descending order (see fig. 2) : — 

 Limestone. 



Marl, of uncertain thickness. 



White sand, with occasional layers of greensand 3 ft. to 4 ft. thick, 

 the total thickness of the whole beds being uncertain owing to 

 the cover of bush and gravel, but certainly between 150 ft. and 

 200 ft. The beds strike north-west and dip south-west 35°. 

 Greensands, dark in colour, over 100 ft. thick ; these pass into the 

 ffreensands seen at the mouth of Waterfall Creek. 

 A noteworthy feature of this section is the absence of any volcanic tuff 

 below the limestone. 



In the upper portions of Waterfall Creek the limestones are most in 

 evidence, and are subject to a series of anticlinal and synclinal folds. Where 

 the anticlines have been denuded greensands are exposed ; this especially 

 is the case on the eastern side of the Hog's Back, a high ridge of limestone 

 near the westerly margin of the basin. In Waterfall Creek and immediately 

 south of it the beds are exposed on a well-marked scarp slope facing east, 

 and the following section is visible :— 

 Limestone. 



Limestone with volcanic-tuff pebbles, 6 ft. thick, passing into 

 Tuffs and greensand, 8 ft. thick. 

 Greensands. 

 Light- coloured sands. 

 These beds exhibit a conformable succession, and dip west at an angle 

 of 55°. 



Immediately west of the section just referred to, above the spot where 

 the river breaks through the limestone, there is apparently a reversal of 

 dip, and coal-beds are exposed under the limestone ; but the country is here 

 bush-covered and the relations are obscure. In all probability the lime- 

 stone and the underlying beds have been slightly upturned, perhaps owing 

 to a fault movement which has produced a line of dislocation passing along 

 the base of the Craigieburn Eange ; but no clear section can be obtained, 

 owing to the covering of bush, soil, and loose debris. 



In that part of the area lying to the north of Broken Kiver the sections 

 are not clear, but exposures in various places show that the beds are 

 existent in their normal stratigraphical relations, with the exception of one 

 locality — viz., that in the immediate vicinity of Parapet Rock. The fault 

 which affects the limestone in Broken River continues to the north-east 

 just past this point, when it passes into a fold without any apparent dis- 

 ruption of the beds. At Parapet Rock the limestone is slightly overturned, 

 but it rapidly flattens out and takes a basin-like form as it follows round 

 Flock Hill. At Parapet Rock and where it crosses Murderer's Creek the 

 limestone is underlain by calcareous tuff, but there is no exposure of the 

 marls and white sands, and their outcrops may be suppressed, as they are 

 in Broken River, as a result of a fault following the strike ; but these beds 

 appear in their normal position when traced round the eastern side of Flock 

 Hill, and finally junction with those in the Broken River below the lime- 

 stone gorge. 



To the north and east of Flock Hill the greensand beds and asso- 

 ciated coal-measures are well developed, especially on the saddle between 

 Murderer's Creek and the creek which runs east of Flock Hill. At the 

 point where these beds cross Murderer's Creek Haast obtained numerous 

 leaf-imprints, which were subsequently identified by von Ettingshausen, 



