738 THE Ti:^-DEPOSITS OF NEW ENGLAND, N.S.W., I., 



and hence do not show the necks and fissures which served as 

 outlets for the Tertiary lavas. The sections will, it is hoped, 

 make clear the intrusive nature of the " Acid Granite," and its 

 close association with the ore~deposits. 



The general geology of the area to be considered may be 

 represented by three units: — 



(1). A series of altered sediments. 



(2). A series of granites and allied rocks. 



(3). A series of basalts and allied rocks. 



Age of the Rocks. 



The complete failure of all investigators, up to the present 

 time to find any fossils in the sedimentary rocks, makes a definite 

 statement of their geological age impossible. Any provisional 

 a»e assigned to this series must rest upon such evidence as litlio- 

 logical characters and continuity with, or proximity to, rocks of 

 known geological age. Lithologically, these sediments, which 

 consist of slates and claj'stones, appear to me very similar to 

 rocks of Ordovician age occurring both at Berridale and Tallong. 

 The New England sedimentary rocks, however, appear to be 

 more metamorphosed, so much so in fact, that at no place was I 

 able to obtain reliable dips for the strata. In qualification of 

 this statement it is only proper to remark that no place investi- 

 gated was distant more than three miles from an igneous contact. 



The slates cannot be traced continuously into rocks of known 

 geological age, neither are there any similar rocks of known 

 <^eological age in close proximity. The series has previously been 

 provisionally classed as Carboniferous on the evidence contained 

 in the following statement from Mr. Gower's report of 1874, to 

 the Department of Mines: — " On Newstead Station, thin bedded 

 shales of bluish-grey and yellow colour crop out, dipping at an 

 angle of 15° in one place and almost vertical in the other, with a 

 general northerly strike. I could not detect any fossils in them, 

 but from their lithological character there is little doubt but 

 that they form part of the carboniferous formation of which th« 

 Rev. Mr. Clarke's report states: ' that the middle beds of this 

 formation, those of the Hunter and Hawkesbury, are widely 



