310 Geology of 



section, close to the southern boundary of the Province, exposed on 

 the eastern slopes of Elephant Hill, not far from the Waitaki, on the 

 upturned edges of the Waihao formation. 



"White underlays, 30 to 40 feet thick, form here the lowest bed of 

 the Oamaru formation, then follows, in ascending order, a seam o£ 

 brown coal, 12 feet thick, dipping 12 degrees to the" east by north. 

 This brown coal, of fair quality, is mostly formed of peat vegetation 

 in which a great number of flattened stems and branches are enclosed, 

 generally arranged in distinct layers (Grlance coal) ,■ the other layers 

 being more dull, and sometimes of a brown colour. Above this seam of 

 coal sharp white quartz sands, about 10 feet thick, lie, which, in 

 descending, gradually run out, and fireclays, about six feet thick, take 

 their place, reposing directly upon the coal. Then follows, a charac- 

 teristic bed of quartz conglomerate or pebble bed with a highly 

 ferruginous matrix, consisting sometimes of more or less angular 

 pieces of slates, sandstones, and rounded pebbles from the "Waihao 

 formation. 



This bed varies very much in thickness ; in some districts it is only 

 a few inches thick, in others 30 feet. The presence of this conglo- 

 merate in many spots all over the ranges, and where the rest of the 

 formation has been thoroughly destroyed, shows convincingly that 

 the Oamaru formation was once of far greater extent. In some 

 isolated spots it has effectually preserved the lower beds, including the 

 brown coal seams ; in others the whole, with the exception of a few 

 fragments of the conglomerate, has been washed away. Quartzsose 

 sands follow, gradually altering to green sands, with Cucullcea, Turi m itella y 

 JPecten Hoclistetteri, Scalaria Jyrata, and Waldheimia lenticularis. In 

 their upper portion these sands become so filled with grains of 

 glauconite that the rock looks quite black. They are succeeded by 

 elaymarls altering to calcareous greensands. These characteristic 

 rocks are sometimes massive, sometimes divided into banks by layers 

 of a more calcareous nature, the latter standing out as protuberances. 

 In some localities they are quite full of grains of glauconite, in others 

 this mineral is less frequent. Fucoid casts are sometimes common ; 

 in other places the whole rock appears to consist almost entirely of 

 minute pieces of corals, echinoderms, and shells. 



Peincipal Fossil Contents. 



The following fossils have been collected in this formation. Some 

 of the localities are given : — 



