914 THE GEOLOGY OP THE NANDEWAR MOUNTAINS. 



EXPLANATION OF PLATES. 



Plate xlvi. 

 Geological Sketch Map of the Nandewar Mountains, and the country 

 between the Nandewars and New England. 

 Plate xlvii. 

 Geological Sketch Map of the Nandewar Mountains only. Scale approxi- 

 mately 4 miles to the inch. 



Plate xlviii. 

 Fig.l. — View of Ningadhun and Yullundunida from the Bullawa Creek 



Valley. 

 Fig.2. — View of the same from a point higher up in the hills. Sandstone 

 formation in the foreground. 



Plate xlix. 

 Fig.l. — View of the Lindesay Group from Bullawa Creek, five miles from 



the mountains. 

 Fig.2.— Scabby Rock, Pilliga Scrub. 



Plate 1. 



Microphotographs of Nandewar Kocks ( x 14, except fig.6 of Plate 1., 



and fig. 3 of Plate li.). 



Fig.l. — Perlitic Pitchstone; Boggabri (N.62)j nicols uncrossed. 



Fig.2. —Dolerite; Dingo Creek (N. 17); nicols uncrossed: the extinguished 



crystal is augite; the gmaller bright crystal near it olivine. 

 Fig.3. — Solvsbergite, Bullawa Creek (N.8), showing microperthitic felspar 



phenocrysts; nicols uncrossed. 

 Fig.4. — Pulaskite Porphyry; Oakey Creek (N. 11); showing phenocryst of 



microcline microperthite near extinction, with zone of orthoclase. 

 Fig.5. — Bostonite ; Dingo Creek (N.51); nicols crossed. Note peculiar 



cruciform twin. 

 Fig.6. — Akerite; Oakey Creek (N.15); nicols uncrossed. Note ojgirine 

 augite phenocryst ( x 21). 



Plate li. 

 Fig.l. — Labradorite Porphyry (N. 12); nicols crossed. 

 Fig.2. — Arfvedsonite-iEgirine Trachyte (N.59); nicols uncrossed. 

 Fig.3. — Monzonose (phonolitic) (N.49); nicolls uncrossed ( x21). 

 Fig.4. — Andesite with Labradorite phenocrysts (N.o3); near Deriah; nicols 



uncrossed. 

 Fig.5. — Phenocryst of Labradorite in alkaline basalt (N.23); nicols crossed. 

 Fig.6. — Akerite (N.15); nicols crossed. 



Plate lii. 

 Figs.la-&. — Handspecimen of Monchiquitic Lamprophyre. 

 Fig.2. — Handspecimen of Labradorite Porphyry. 



(The figures of this Plate from photos by H. Gooch). 



