242 GREAT SERPENTINE BHLT OP NEW .SOUTH WALES, VI., 



south. This is possibly iii the same line of fault as the carbon- 

 ated serpentine by Cobbadah Creek, mentioned above. Directly 

 east of it, also, the rocks are intensely folded Burindi rocks of 

 typical dark green colour, \vitli small calcareous bands. These 

 are folded into sharply packed anticUnes and synclines. The 

 falls on Hall's Creek are cutting back into these mudstones, 

 which, near them, contain pebble-bands with pebbles of the types 

 usually present in Burindi and Rocky Creek conglomerates. 

 Half-a-mile north-east of the falls, in Portion 46, Parish of Hall, 

 is a band of limestone about 100 yards long, and <S yards thick. 

 It is almost entirely made up of Lithostrot'ion sp., but also con- 

 tains traces of St/rinyopora, a cyathophylloid coral, and crinoid- 

 stems. This rock is intercalated with Burindi mudstones, and 

 is, perhaps, to be correlated with the Lithostrotion-Syriiiyojjora 

 limestone near Eulowrie, 14 miles to the west, which has been 

 considered to be near the base of the Carboniferous Series (see 

 p. 269). About 200 yards east of this is the serpentine. 



The description of the writer's collection of fossils from Hall's 

 Creek has kindly been undertaken by Dr. Stanley Smith, of 

 University College, Aberystwyth. 



Following the disturbed region north from here into the valley 

 of Hall's Creek, the stratigraphy becomes very complex. The 

 Carboniferous rocks cease, and the Upper and appai-ently Middle 

 Devonian beds appear. The outcrops are extremely poor and 

 scattered, owing to the wide spreading of the alluvial fans by 

 the torrents that descend from the ranges on either side. In 

 Mr. S. Wither's property (Portion 44, Parish of Hall), four miles 

 to the north of the Lithostrotion-\\mQ^Ume, are two lenses of 

 limestone of quite a different type. It is highly crystalline, but 

 contains traces of corals which have been tentatively referred to 

 the following forms: — Stroinatopora or Stromatoporella, Favosites 

 multitahalata^ Favosites j^ittfnani, Actinocystis or a Cystiphylloid 

 coral, GyathophyUum^ Syringopora. The last is very abundant. 



The limestone must, for the present, be referred to one of the 

 Middle Devonian horizons, probably the jSemingha horizon. It 

 does not lie parallel to the serpentine-boundary, but strikes N. 



