96 On the Occurrence of the Diamond near Mudgee. 



3. Two-mile Elat. — Three miles below the last, at some distance 

 on tlie left bank, comprising five basaltic knolls and ridges at 

 various intervals a'onga large elliptical curve that the old channel 

 followed but which the present river has cut off. Computed 

 altogether at about 70 acres. 



4. Rocky Eidge. — On the right bank, one mile below Two-mile 

 Flat, a scarped basalt hill, extending a short way up a tributary 

 creek. About 40 acres. 



5. Horseshoe Bend. — On the left bank, opposite the Eocky 

 Eidge, a crescent-shaped area of basalt, with its concavity facing 

 the river. About 20 acres. 



6. Hassall's Hill. — A similar crescent area, with its convexity 

 towards the river, situated half-a-mile south-west of the Horse- 

 shoe, and covering about 340 acres. 



Further down the river, on the east side, about 2\ miles west 

 of Hassall's Hill, there is another small outlier of basalt resting 

 on drift, as well as several uncapped drift or ' made ' hills ; these 

 are as yet untried for diamonds, though formerly worked for gold. 

 Below this there is no trace of basalt for 7 or 8 miles further 

 down the river, when we reach a very small outlier on the right 

 bank, but whether the older drift underlies it we cannot say. 

 ' Made ' hills of drift, apparently the Newer Pliocene, skirt the 

 banks of river on both sides to its junction with the Macquarie ; 

 but there is no further trace of basalt. 



Eiver-drifts at high levels are traceable in many parts of the 

 upper course of the Cudgegong, above Mudgee ; but no diamonds 

 have been discovered in them. In one patch a singular deposit 

 of crystalline cinnabar has been found. 



In all the above six localities the basalt has been sunk through 

 and tunnelled under, and the drift containing diamonds is 

 invariably found beneath. 



The basalt, besides resting upon the drift, frequently comes 

 into direct contact with the metamorphic shales, slates, and 

 sandstone or greenstone rocks, which form the basis of the 

 country. 



In spots where the basalt has been denuded away, the drift has 

 either disappeared entirely, or become scattered over the 

 immediate neighbourhood. 



The drift rests on vertical indurated strata, or on massive 

 greenstone ; it varies extremely in thickness from a few inches 

 to 30 feet, according to the irregularities, in some cases, of its 

 own upper surface, which is not uniformly level, and in other 

 cases, due to the old river bed. Its composition is various, but it 

 generally includes coarse and heavy material, some of the 



