714 GREAT SERPENTINE BELT OF NEW SOUTH WALES, ill., 



tising omphacite, and irregular reddish-brown areas, recalling the 

 pleochroic decomposition-products of olivine in certain gabbros 

 and basalts, though not quite like iddingsite. Magnetite, which is 

 very abundant, and chalcopyrite, occur in irregular grains, the 

 former having been the earlier to crystallise. The carbonate-matrix 

 contains the same ferromagnesian minerals, and small grains of 

 sphene. Another example contains calcite, garnet, and diopside 

 only; while several are analogous to N.T., 444, at Carmichael's 

 Farm. They consist of orthoclase and albite in intimate mosaic, 

 together with finely granular quartz. Orthoclase predominates. 

 Green diopside occurs, scattered about in irregular, isolated but 

 optically continuous areas. Garnet forms highly irregular plates, 

 and is sieve-like on the margin; it may contain groups of narrow 

 calcite-plates. 



Some rocks also occur, differing from the above in the presence 

 of granular, green omphacite, and the dominance of oligoclase over 

 orthoclase. 



These rocks are distinguished from all the other limestones by 

 the character of the garnets, and the presence of the copper- 

 minerals. 



The small patch of altered limestones in Portion 159, of Attunga 

 Parish, is the most complex. All the specimens to be described, 

 occurred within a yard or two of each other, and no granite was 

 seen, in situ, nearer than two miles away. It is probable that this 

 small occurrence of metamorphic limestone lies at the extremity of 

 an apophysis of the granite-massif, and has been in a favourable 

 situation to receive much new material from the granitic emana- 

 tions. 



The intrusive rock is probably M.B., 167, a grey rock, with pink 

 felspar-crystals. It consists of oligoclase and orthoclase, both 

 coarsely granular, and the former showing well marked pericline 

 twinning. There are also numerous, large grains of sphene. Much 

 of the limestone has been absorbed, and has given rise to diopside 

 in numerous prisms, and phlogopite in small flakes. Both of these 

 are decomposing to chlorite. Birefringent garnets also occur. 

 Much carbonate still remains, in one slice forming about one-third 



