347 



A point of interest is also seen in the occurrence of a 

 considerable thickness of recent alluvium in each bore resting 

 on the marine beds. In the case of the Kruger Dam Bore 

 there are 200 feet of clays, sands, and gravels, and in No. 4 

 Bore similar deposits have a thickness of about 300 feet. At 

 present the locality has no definite river channels, but the 

 drainage is entirely local and disconnected. The upper, or 

 fluviatile, portions in the respective bores probably represent 

 antecedent river channels which were formerly connected with 

 the older north and south drainage of the country. A sample 

 of the deposits supplied to me from the level, 60-100 feet, in 

 the No. 4 Bore consists of a clean white sand, the grains of 

 which are fine to medium in size, and are almost exclusively 

 composed of quartz, mostlv of a transparent variety; the 

 particles are rounded by attrition, especially the larger grains. 



With reference to the fossiliferous horizons, the material 

 that carries the organic remains in the Kruger Dam Bore is 

 a tenacious blue clay, but in the washings there are also some 

 extra large and rounded quartz gi-ains that show a high degree 

 of polish. In No. 4 Bore, the material from 298 feet to 300 feet 

 is a dark-coloured clay; from 300 feet to 318 feet, a black to 

 greenish-black clay; and from 318 fee': to 325 feet, a black 

 and very sticky mud. Each sample carries a considerable 

 number of glauconitic granules, which, in many instances, 

 have infiltrated foraminiferal shells and other organisms, or 

 reduced them to pseudomorphs. The jrlauconite readily 

 oxidises, by which the iron present, as a silicate, passes into 

 a hydrous oxide of iron, or limonite, and becomes of a dark- 

 brown colour. Most of the Ampkisterjinae present in the 

 material have suffered such a change. Carbonaceous material 

 is present in the form of black, cylindrical filaments or stems, 

 some of which nre pyritized. 



THE ORGANIC REMAINS. 



FORAMINIFERA. 



It is interesting to note that the first material examined 

 for microzoa from the Lower Cainozoic series of Australia was 

 obtained from a locality situated about sixty miles due south 

 of the bores now under description, which has been until now 

 the furthest north for these beds in South Australia. In 

 1876, Mr. R. Etheridge, jun., then of Edinburgh, sent to Mr. 

 H. B. Brady some material from a Government well that had 

 been sunk about half-way (thirty miles) between the Burra 

 Burra Mines and the Nor'- west Bend on the Murray. From 

 this material Mr. Brady determined twenty-four species of 

 Foraminif era ; and his" brother. Prof. G. S. Brady, four species 



