260 Transactions. 



orthoclase and plagioclase, both micas, interstitial quartz, and titanite 

 in grains derived from ilmenite. In some of tlie specimens there is very 

 little muscovite, and an occasional garnet and zircon ; epidote occurs spar- 

 ingly. The Preservation Inlet granites have been described by Hutton (10) 

 as syenites. 



Chalky Inlet. 



The only rock from here is a gneissic granite from North Port. It is 

 dark grey in colour, very indistinctly schistose, with biotite feldspar and 

 quartz plainly visible. Under the microscope it shows occasional strain- 

 efiects. The feldspars are of both kinds, containing much sericitic material 

 and at times micrographically intergrown with quartz ; more biotite is 

 present than in Preservation Inlet granites, and the flakes are frequently 

 bent ; muscovite is an important constituent ; apatite needles, small 

 garnets, and zircons are also present. 



Dusky Sound. 



Collections were made at Pigeon Island, at Duck Cove on Resolution 

 Island, and at Pickersgill Harbour on the south side of the Sound, where 

 Captain Cook established in 1768 a temporary astronomical station. 



Gneiss (D 1). — From Pigeon Island. In the hand-specimen the rock is 

 whitish, showing indistinct foliation ; quartz, feldspar, and biotite, and 

 some garnet, are plainly visible. Under the microscope it appears com- 

 posed of much quartz in variable-sized grains, and feldspar (orthoclase) 

 showing the effects of strain ; plagioclase and microcline are both present ; 

 some of the feldspar exhibits schiller effects ; there is much biotite, some 

 epidote and hornblende, and sphene in idiomorphic crystals occasionally 

 included in mica and hornblende ; a little apatite and zircon are present ; 

 the structure is at times cataclastic. 



Gneiss (D 2). — From Pigeon Island. In the hand-specimen the rock 

 shows marked schistose structure. It is composed of microchne, plagio- 

 clase, quartz, muscovite, and biotite ; granophyric growths are common ; 

 the structure is markedly cataclastic. 



Garnet Pyroxene Gneiss (D 3). — From Duck Cove. This is the rock 

 (G 24) described by Marshall (14). It shows abundant garnets, as well as a 

 green F.M. mineral associated with a white feldspar. In section it is com- 

 posed of plagioclase, a Uttle orthoclase, a fair amount of quartz, and garnets 

 in grains with borders of pale-green secondary monocUnic pyroxene derived 

 from the garnet, which shows marked signs of corrosion. A good deal of 

 hornblende also occurs, a small amoimt of biotite, and much strongly 

 pleochroic secondary epidote ; rutiie in small grains is of frequent occur- 

 rence. 



Gneiss (D 4). — From Duck Cove. A schistose rock showing epidote 

 freely. It is composed of partially sericitised feldspar, partly plagioclase, 

 a small amount of quartz, greenish hornblende, and strongly pleochroic 

 secondary epidote (much of the epidote so frequently met with in the area 

 appears to be primary). Ilmenite occurs in grains, with much secondary 

 sphene in grains and aggregates derived from it, as well as apparently 

 primary sphene in idiomorphic crystals ; apatite needles are common. 



Amphiholite (D 15). — From Duck Cove. A dark rock formed chiefly 

 of hornblende in rude parallel arrangement. In section it is composed 

 almost wholly of green-brown hornblende, much rutiie in grains and idio- 



