PLATE X. 



13. Granodiorite from Quarry at the Gap, Enoggera. The intergrowth 



of quartz and felspar is well shown : also the presence of 

 biotite in the right-hand corner. 



14. Quartz Diorite, from Bendleys selection, Mt. CrcsbJ^ The dark 



mineral is augite, while the grev and white minerals are plagioclase, 

 and to a small extent, quartz. 



15. Granodiorite from Greymare, showing clear quartz, cloudy plagioclase 



(zoned) and black mica. 



16. Sandstone frojn Mitchell's Hong Kong Quarry, Warwick. The 



coarse and uneven nature of the stone is shown. 



17. Sandstone from Quarry at Highfields, showing the fine-grained 



character of the stone and the very abundant cement. 



18. Sandstone from Sydney. This is shown for comparison with the 



other sandstones. 



J 



