BY W. \. BKNSON. 673 



that the hydration of that small ham! «»f serpentine could be the 

 causo of its own shearing ami the local dislocation. In bhe main 

 intrusion, the schistose serpentines bend to occur along the cast 



wall, ami, to a less extent, on the west wall of the intrusion, 

 points where the easterly thrust would he most felt. Mere, the 

 massive serpentine is locally drawn out into schistose serpent ine. 



Leaving " eyes " of massive rock imbedded in the schist, gradually 



diminishing in size till the zone oi maximum shear is reached. 

 This is a feature sometimes observed in Alpine serpentines (fide 

 Professor Bonney). 



A few rocks occur, in which pressure has produced a linear- 

 parallel, rather than a Lamellar parallel or schistose structure. 

 This seems to he the result of simple pressure without shear. 

 Such rocks are rare, hut instances occur at the Lone Hand Mine, 



south oi Bingara [M.B., L99] and elsewhere, Less well developed. 



From Mr. I). A. Porter, 1 have received a serpentine occurring 

 probably near the head of Attunga Creek. It is a bastite- 

 serpentine traversed by numerous parallel veins oi chrysotile, 



about half an inch apart, narrow where traversing the bastite- 

 crystals, but splitting up into liner, anastomosing veins where 



crossing the intervening oli vine-serpentine (Plate xxvi., fig.7). 



(6). Before describing typical antigorite serpentines, a group of 

 rocks should be mentioned, that appear to show the first stages 

 in the transformation into antigorite serpentine. For eon- 

 venience, these may be termed "felted serpentines." The mass 

 of the rock is a tine, grey-brown, fell like mass of a dusty nature, 

 polarising in yellowish tints. In the main, its appearance sug- 

 gests derivation from a pyroxene, perhaps diallage, for true 

 bastite occurs also, and a kind of mesh-structure in some portions 

 likewise. Small, branching veins traverse the rock, bordered 

 perpendicularly by chrysolite fibres; and sheared chrysolite-veins 

 may be present also [e.g., N.T., 143; a compact, mottled-green 

 serpentine from the mouth of Sheep Station Creek, Bowling 

 Alley Point]. The further stage in alteration is exemplified by 

 N.T., 103, occurring on the Peel River, a mile to the north-west. 

 In this, the dusty-brown material has diminished in quantity ; 

 wide zones, separating the dusty areas, consist of mica like 



49 



