The Stony Creek Basin, l)<i ijlestord. 367 



It is evident that tlioug'h a portion of the basin is occupied 

 by Lioustrine deposits, they have been much disturbed since 

 their deposition. The depth to which the black clays extend 

 has not been certainly proved. The shaft of the Grand Mystery 

 Company is the deepest of which I have foimd any record. The 

 " Daylesford Express " of March 17, ISG-i, \\Titing of the fourth 

 attempt of this party to bottom the basin, says: — "The drift 

 has been safely gone through in the new shaft, which is about 

 110 feet from grass, and the bottom of which is covered with 

 waterworn boulders, indicative of the nearness of the gutter. 

 Gold in small quantities has already been found in the shaft." 

 On April 9 the same paper says: — "This company 

 struck the reef last week at 111 feet, when a large quantity of 

 water flowed in. A prospecting drive was then put in eastward, 

 but after driving 20 feet the black clay was struck in the face 

 of the drive, when it was determined to sink the shaft deeper 

 and open to the north. After supplying new timber to the shaft 

 in the place of that which had been broken by the swelling of 

 the bliiek clay, the further sinking of the shaft was commenced, 

 and it was found that the reef dipped rapidly, one-half of the 

 shaft being in headings, the other in reef at 117 feet. A fair 

 prospect was washed, and it improves as the shaft progresses." 

 Reef in these notices, according to usage of alluvial mining, 

 means bedrock. Beyond this I find no reports of the company's 

 operations except a notice of a 10s. call. 



Local miners call this black clay "dyke," and they apply the 

 same term to what is probably a fault rock exposed in the next 

 valley. It is quite possible that they had reached bedrock long 

 before, but had not recognised it till the footwall of the fault 

 was met. This supposition is in accordance with the fact that 

 the shaft was close to the side of the basin, which is here very 

 steep above the level of present surface in the basin, and must 

 continue very steep below. Most likely the limit of the basin 

 on this, the southern, side is a fault. The so-called water-worn 

 boulders may easily have been broken and worn fragments of 

 the bedrock. 



It is certain, however, that the floor of the basin lies well 

 below the present creek level, and much below the levels of the 

 deep leads. Its present position is not its original position, and 



