116 VOLCANIC AREA OF EAST MORETON, ETC., DISTRICTS, Q., 



inclusions of biotite, magnetite, apatite and leucoxene. Chlorite 

 and dusty magnetite are its decomposition products. The biotite 

 occurs in corroded phenocrysts with ragged ends, and contains 

 numerous inclusions of magnetite. It is often surrounded by 

 secondary chlorite. The primary magnetite is of a brownish 

 tint and gives leucoxene as a decomposition product. Hence it 

 is titaniferous. 



(4) Order of consolidation normal. 



(5) Quartz, orthoclase and plagioclase being nearly equal in 

 amount, this rock is a tonalite or red quartz-mica-diorite. 



Sp. No.78. Granite. Loc: Police Paddock, Woodford. 



Handspecimen : colour of weathered boulders bluish; colour of 

 fractured surface pinkish with bluish-black specks. 



With a pocket lens the following minerals are recognised — 

 (1) orthoclase of a pink colour, showing Carlsbad twinning, and 

 having a strong tendency to idiomorphism; (2) quartz, quite 

 allotriomorphic; (3) biotite in black shiny flakes; (4) bluish-black 

 hornblende; (5) greenish plagioclase. 



The rock is even-grained and medium-grained. A suitable 

 name would be Dioritic Granite. 



Sp. No. 77. Granite-Aplite. Loc: Police Paddock, Woodford. 



Colour pale pink; grain-size even, but finer than Sp. No.78. 

 This rock occurs as veins traversing the granite described above 

 (Sp. No.78). The constituents are quartz and orthoclase inter- 

 grown in a graphic manner. A little hornblende decomposing to 

 chlorite is present in minute amount. A few specks of pyrites 

 also occur. This rock is an aplitic differentiation product of 

 Sp. No.78. 



Sp. No.73. Granite. Loc: Terror's Ck., Upper North Pine. 



This rock is very like that of Sp. No.78 from Woodford, and 

 contains the same constituents. The grain-size is medium, but 

 coarser than in Sp. No.78. 



The granite from Big Hill (Durundur Hill) on the Caboolture- 

 Woodford Road is very decomposed, so much so in places as to 

 partake of the nature of arkose. It is coarse-grained, and con- 



