270 Geology of 



proportions with boulders of sedimentary origin, whilst the sections 

 of Trinity Hill show the gradual change from the one series into the 

 other. These conglomerates, like the whole series to which they 

 belong, are much jointed, often a system of four distinct joints being 

 well developed, crossing each other at various angles, and cutting 

 with sharp planes through the hardest boulders. The palaeozoic 

 outlier in the Gawler Downs belongs, without doubt, to this series. 



3. Shales alternating with gritty sandstone, coal-sandstone, and 

 bands of clay-ironstone now follow. Some of the sandstones are full 

 of the impressions of fossil ferns, others full of those of roots or of 

 drift timber. Tlattened stems of trees are also enclosed, often of 

 considerable size, the bark altered to a scaly powdery coal (culm)* 

 the interior filled with sandstone, often of a much finer grain than the 

 surrounding rocks. Amongst the fossil flora I observed, Pecopteris, 

 (two or three species), Camptopterii, Taeniopteris, Otopteris, Cyclopteris, 

 Sphenopteris, Cycadites ? Palceozamia ? Taxites.? Equisetites. \ The 

 Pecopteris beds are usually distinct from the Tdeniopteris beds. Some 

 of the shales consist almost entirely of the leaves and stems of ferns. 

 Amongst them the beds of sandstone are generally the most important, 

 some of them having a thickness of over twenty feet, although 

 generally the arenaceous and carbonaceo-argillaceous strata alternate 

 rapidlv with each other, and are occasionally only a few inches thick ; 

 the whole thus having a ribboned appearance. 



This series is together also several hundred feet thick. 

 ■1. Xo. 3 is covered by conglomerate beds like Xo. 2, but of 

 smaller dimensions. 



* The following analysis of two specimens of this culm was made in the laboratory of the 

 Geological Surrey in Wellington :— 



1, and 2, Bituminous Coals (Culm). 

 Colour intensely black, lustrous, very fragile. 

 Colour of powder black, that of ash light buff. 

 No. 1 cakes freely, the other even more so. 



Appboxihaie Analysis. 



No. 1. No. 2. 



Water 227 2"12 



Fixed carbon 55"10 50 - 04 



Hvdro-carbon 11-95 13*44 



Ash 30-63 34-40 



100- 100- 



Evaporative power of No. 1 = 71 

 „ „ No. 2 — 6-0 



t Dr. Hector has compared fossil plants found near Keefton, which also contain TaeniopUas, with 

 the Eajamahal Flora of India. 



