78 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb, 2, 



white or yellow clay, known by the miners as "the Pipe Clay." 

 This is sometimes of unknown depth, and sometimes passes im- 

 perceptibly into the vertical laminae of soft micaceous slate. In some 

 of these gullies there is a continuous hne of workings half a mile in 

 length. The richest deposit is always found in what appears to be 

 the ancient channel or bed of the gully, where the opposite slopes 

 of the rocky gully meet deep beneath the overlying strata of gravel 

 and clay. The breadth of the area which yields gold is usually not 

 more than a few feet, rarely if ever more than a few yards. The 

 superior strata clearly owe their origin to running water. They dif- 

 fer much in composition in different localities. They may be hard 

 or soft — may consist of tenacious clay or of sandy gravel. When 

 first turned up they almost always are of some bright hue of red, yel- 

 low, or white ; but this soon fades away on exposure to the air. It is 

 remarkable, that these gullies are, with scarcely an exception, on the 

 south side only of the valley. 



3. The third kind of deep workings are those on the sides and 

 crests of the low rounded hills or acclivities at the sides of the auri- 

 ferous gullies. It often happens that the width of an auriferous 

 gully is contracted before it falls into the main valley by spurs from 

 the lateral hills, which, protruding from either side, form a kind of 

 gateway to the gully. In such localities the gold deposit was found 

 to continue across the gully up to the foot of these enclosing hills, 

 and thence up their sides to the rounded crest, where the rich field 

 commonly ceases. In the gully below, the gold-bearing deposit may 

 be at a considerable depth. At the crest of the hill it will also be 

 deep ; but intermediatelj', at the foot of the hill, the " holes " will 

 be perhaps only 2 or 3 feet deep, or the gold may in this intervening 

 space be scattered in the surface gravel ; so that a section through 

 the hill and gully below would exhibit the gold deposit somewhat 

 thus — fig. 3. 



Fig. 3. — Section through an Auriferous Chilly and contiguous Hills. 



Gold-diggers' shaft 



or "hole." Open working. Barren "hole." 



a. Alluvial clays, red, yellow, and white, in irregular beds. 



b. Auriferous deposit. c. Slate-rock. 



The alluvial strata on the sides and tops of these hills have a:j 

 general conformity to the present surface, but are extremely irregu- - 



