140 



Other titaniferous rocks in which the similarity is not so 

 dose are : — 



Norite. — South Black Hill (near), contains ilmenite — Dr. 



Chewings, Inaugural Dissertation, Beitrage zur Kennt- 



niss der Geologie des Slid- und Central-Australiens, 



Petrographisclier Anliang, Heidelberg, 1894. 

 Amphibolite (after Diabase). — Mt. Pleasant, secondary 



hornblende, plagioclase, and titanite — C. Chewings, 



op. cit. 

 Uralitic Diabase. — Port Elliot, hornblende paramorphs, lathy 



felspar, biotite magnetite, and ilmenite — C. Chewings, 



op. cit. 

 Epidote Rock. — Mt. Zeil, MacDonnell Ranges, coarse-grained 



epidote. with spliene quartz and sagenitic rutile — C. 



Chewings, op. cit. 



DESCRIPTION OF PLATES. 



Plate III. 



Fig. 1. Syenite. Locality, Section 3240, Hundred of Yatala. 

 Note the large crystal of moire orthoclase-perthite, 

 also biotite, magnetite, and diopside. Polarized light. 

 Magnification, 32 diams. 



,, 2. Microcline syenite similar to that in Section 563, Hund- 

 red of Yatala. Note also uralite and sphene. Polar- 

 ized light. Magnification, 32 diams. 



,, 3. Ilmenite diopside diorite. Section 5657, Hundred of 

 Yatala. Note also plagioclase, sphene, and apatite. 

 Ordinary light. Magnification, 16 diams. 



,, 4. Scapolite amphibolite. Inglewood. Note actinolite, large 

 grain of scapolite, and much diablastic scapolite, micro- 

 cline, and sphene. Polarized light. Magnification, 29 

 diams. 



,, 5. Gneissie aplite. Section 5519, Hundred of Yatala. Note 

 quartz and microcline. Polarized light. Magnifica- 

 tion, 15 diams. 



,, 6. Tourmaline-quartz pegmatite. Stirling East, near Aid- 

 gate. Note graphic nature of intergrowth. Ordinary 

 Hght. Magnification, 13 diams. 



PL.4TE IV. 



,, 7. Diorite. The Gorge, south of Normanville. Note 

 felspar hornblende, dark-edged uralite, and magnetite. 

 Ordinary light. Magnification, 16 diams. 



,, 8. Augen schist. Normanville Gorge. Note moire ortho- 

 clase, perthite, and quartz lenticles. Polarized light. 

 Magnification, 26 diams. 



,, 9. Quartzose felspar porphyry. A boulder in Cambrian 

 till. .Jamestown. Note phenocrysts of felspar and 

 fine-grained nature of base. Polarized light. Magni- 

 fication, 17 diams. 



,, 10. Aplite. Olary. Note black cuboids of titaniferous 

 magnetite. 



,, 11. Yatalite vein with portion of diorite attached. For key 

 see fig. 3, p. 126. 



Plate V. 

 Geological Map of district around Houghton. 



