286 Geology of 



great variety. "What gives these lowest beds forming the base of the 

 porphyries a still greater interest is the occurrence of plant beds, and 

 seams of brown coal, mostly of inconsiderable thickness, associated 

 with them. The locality where the whole series can best be studied, is 

 situated in the Cox Hills at the south-eastern base of Mount Somers. 

 Upon the palaeozoic sedimentary rocks, consisting priucipally of a coarse 

 sandstone decomposing to a loose ferruginous gravel, repose thick 

 beds of green sands, gradually altering to yellowish and white 

 quartzose sands ; thickness about 500 to 600 feet. They are capped 

 by ferruginous shales three feet thick, overlaid by four feet of snow 

 white sands. Twenty inches of shales, full of impressions of leaves, 

 follow, but unfortunately with scarcely any pieces large enough for 

 recognition. Some of these leaves, however, I believed at the time to 

 be of a truly dicotyledonous character. Although, after repeated 

 examination of a number of specimens received since my first survey was 

 made, I am now inclined to refer them to the coniferse. One of the 

 most perfect of these fossil leaves has great resemblance with the 

 Dammara of the overlying Waipara formation. These shaly beds are 

 again overlaid by a great thickness of sands, mostly of a pure white 

 colour, and with veins and irregular portions of yellow or salmon- 

 coloured hues. The latter are covered by shales, with a dip of 46° to 

 W.S.W., followed by three feet of a partially altered brown coal, 

 showing sometimes still the woody structure ; this seam is covered by 

 16 inches of gritty sandstone. 



Then follow, in ascending order : — Twelve inches of yellowish or 

 bluish tufaceous clays, six to eight feet of shaly beds, with indistinct 

 remains of plants, three feet of bluish or greenish tufaceous clays, 

 one to two feet of porcelain jasper, evidently altered and burnt by the 

 next beds, which are of an eruptive character. These porcelain jaspers 

 contain some lapilli, or even smaller blocks of pitchstone enclosed in 

 them. They gradually alter into a whitish tufaceous mass, consisting 

 of lapilli and ashes cemented together, without doubt the result of the 

 destruction of pitchstones during an eruption. These beds are full 

 of angular or sub -angular pieces of black pitchstone, evidently much 

 decomposed, and from one inch to 20 feet in diameter ; the whole 

 having a thickness of at least 100 feet. They are capped by a 

 stratum of pitchstone about 10 feet thick, upon which quartziferous 

 porphyries iollow, first with a hyaline, afterwards with a more felsitic 

 matrix. This first great stream forms the lowest of a great succession 

 of similar ones rising to the summit of Mount Somers, that 



