502 GREAT SERPENTINE BELT OF NEW SOUTti WALES, L, 



The Baldwin Agglomerates occur in the Bingara Range, rising 

 from below the Barraba Series on the Gwydir River. They con- 

 tinue southwards, bordered by powerful faults on the east and 

 west. Disappearing below the Barraba Beds in the region of Cob- 

 badah and the Manilla River, they rise again to form the Black 

 Mountain and Baldwin Ranges, which are cut off to the west by 

 powerful faults; and dipping to the east, they pass, in a syncline, 

 below the lower Manilla River, and rise again to form Pyramid 

 Hill, above the town of Manilla. From here southwards, they have 

 not been noted, until one comes to the three small occurrences on 

 Cleary's Selection, near Tamworth. Southwards thence, they seem 

 to die out rapidly. They are not seen south of Black Jack, unless 

 the few yards thick, of rather coarse tuff that separates the Bowl- 

 ing Alley from the Nundle Series, may be considered their repre- 

 sentative, as its lithology would suggest. 



(c) The Barraba Series lies conformably above the Baldwin 

 Agglomerates. They are the most wide-spread division of the 

 Palaeozoic rocks west of the serpentine-line. They consist of 

 banded shales and mudstones, containing radiolaria, with slightly 

 coarser-grained layers free from these fossils. Interbedded with 

 these, are fine or coarsely grained bands of acid or intermediate 

 tuff, or, rarely, conglomerate bands are present. More frequent, 

 however, are wide or narrow zones of a tuffaceous agglomerate, 

 recalling the Baldwin Agglomerates. In places, there are masses 

 of rocks that might be classed as grauwackes ; these are particular- 

 ly well developed south and east of Cobbadah, and in the Nundle 

 district. There are frequently also large or small lenticles of blue 

 argillaceous limestone, which is quite free from organic remains. 

 Throughout, Lepidodendron australe is particularly abundant. 

 Indeed, the distinction between the Barraba Series and the Burindi 

 Series, lies largely in the absence of L. australe (and radiolaria) 

 from the latter. Stonier reported L. australe to occur with the 

 Carboniferous Marine Beds at Burindi(6), but this is not con- 

 firmed by later collections. 



As previously stated, these beds form the greater part of the 

 area mapped, and extend far to the west of the serpentine, forming 



