1066 DR R. K1DSTON, MR T. C. CANTRTLL, AND MR E. E. L. DIXON. 



cases, of white vein quartz ; but grey or purple and green quartzites — these always 

 better rounded than the quartz-pebbles — are, in a few beds, as frequent as quartzes, 

 and in others may generally be found. Subangular red jaspers are occasional ; and 

 highly weathered igneous rocks — ? felsites — are abundant in the conglomerate that 

 marks the base where the formation rests directly on the Lower Old Red Sandstone. 

 Besides these fragments of older rocks, flakes of contemporaneous clays are generally 

 included. 



The sandstones are imperfectly cemented as a rule. Many break down readily 

 to pebbly sand, and they seldom form crags, or are workable for building-stone. The 

 cement appears to be largely siliceous, and some beds are distinctly quartzitic ; but, 

 as may be inferred, true quartzites are rarely, if ever, developed. In the brown 

 sandstones the cement is partly ferruginous, but it is rarely calcareous. 



A variety of sandstone is noteworthy as having yielded the only plants of zonal 

 value yet obtained. It is grey and well laminated, the bedding-planes being thickly 

 sprinkled with carbonised vegetable-debris. Here and there something more than a 

 mere suggestion of form about the plant-remains encourages the hope that the next 

 plane to be uncovered will reveal something good — a hope that has not yet been 

 justified. This is the more to be regretted as the age of the formation is important. 

 Dr Kidston, however, has succeeded in identifying the forms mentioned on p. 1076 

 from this unsatisfactory material. The levels of those from Studley Tunnel are 

 unknown. The Stigmaria from the Cornbrook dingle was found in sandstone below 

 the waterfall, at a level several hundred feet above the base of the group, and the 

 Lejndodendron (L. Veltheimi Sternb.) from the same dingle occurred in one of the 

 highest sandstones exposed, nearly 1000 feet above the base. 



The more massive sandstones occasionally contain plant-remains which are 

 sometimes large, as in the case of the Stigmaria mentioned above but are usually 

 without well-preserved surface-markings. Small rootlets, like thos' a the underclays, 

 are frequent in a few sandstones. 



The clays occur as frequent, but thin, bands between the much thicker masses of 

 sandstone. The clays are dicey and friable, of various bright colours (red, purple, 

 buff, or yellow), or grey, dark or light. Some of the light-grey bands are penetrated 

 by rootlets at right angles to the bedding and are indistinguishable from Coal 

 Measure underclays, and occasionally such a band is overlain by black carbonaceous 

 clay. True shales are not common. 



Thin but unworkable coals are present. Occasionally a smut, or a highly 

 carbonaceous clay or shale, may be seen, and coal-streaks occur in some of the 

 sandstones. In the Cornbrook dingle an old working suggests that an attempt has 

 been made to work a bed, and at one or two places elsewhere a coal or coals are 

 said to crop out. 



The limestone occurs as blue-hearted lenticles a few inches thick, in grey shale, 

 weathered to buff laminated clay, both limestone and clay containing marine fossil 



