CARBONACEOUS DEPOSIT, BEACONSFIELD. 323 



of these that the lignite has been encountered. It was first 

 found in the No. 5 level of the Tasmania, a httle west of the 

 second or western " cross-course," one of two large faults 

 that cut through the Tasmania reef. The strata in this 

 part of the mine are very much disturbed, preserving 

 no regular strike and dip, and being visibly greatly 

 fractured and shaken. The lignite was here mostly found 

 in sandy soft layers between hard beds of coarse grit, 

 presenting the appearance of being contemporaneous with 

 them. Early in 1891 the Moonlight Company began to 

 drive eastward from their shaft at the 422 feet level, and had 

 not gone many feet when the lignitic mineral was encoun- 

 tered in great abundance. The beds of grit in which it was 

 found were quite similar to those in the Tasmania mine, and 

 corresponded very well with them in their position, thus at 

 first sight strongly corroborating the theory that the 

 carbonaceous matter was in the beds from the beginning. 

 But as work progressed it was found that it had also 

 penetrated into cracks and joints in the beds, as well as 

 being in loose sandy layers between them, and, indeed, was 

 brighter and purer in these cracks than anywhere else. 

 Sharp angular stones of grit were obtained, too, completely 

 coated with the lignitic substance, and an examination of 

 these showed that they had been hardened and fractured 

 before it had been deposited. Inside these pieces of stone 

 there was no sign of carbonaceous matter. In this company's 

 workings, as in the Tasmania mine, the strata were very 

 much shattered where the black substance was found. 



This broken state of the country suggested the explana- 

 tion that surface waters from a swamp might have found 

 their way down into it, and gradually deposited the 

 carbonaceous matter in the crevices and soft porous beds. 

 The more this was examined the more feasible did it appear, 

 until now we are convinced that it correctly explains the 

 occurrence. The absence of lignite in the upper workings 

 of the mines, which might seem an objection to the acceptance 

 of this theory, is easily explained : if it ever existed there it 

 would rapidly be oxidised and destroyed l)y tlie oxygen in 

 the waters brought down from surface in comparatively 

 recent times since tlie surface has assumed very much its 

 present shape. The deeper parts of the deposit, being 

 considerably below the permanent water level of the district, 

 have been protected from the influence of the atmosphere. 

 In the Moonlight mine it occurs some 90 feet below the 



