Clarke — Geology ofWcstern Australia. 505 



being soft originally, altered by silicification. Altbougb imagi- 

 nation may give an idea of organic form, it is pretty certain that soft 

 mud drying might take and retain just such a structure. Its polished 

 surface implies drifting and exposure. 

 G.—From While Peaks Lat. 31° 2' 30^^ S., Long. 121° 12' E. 



20. White silicate of alumina. 



21. White [? porcelain] clay. Not sufficiently tested. 



22. Pink bedded deposit. 



23. Yellow deposit. 



24. Fine bluish white deposit with black points of (?) iron, a sili- 

 cate of alumina. 



25. Greyish blue soft deposit, a tolerably good fire clay ; a silicate 

 of alumina, with common salt, magnesia and lime in small pro- 

 portions. 



26. White and yellowish sandy aluminous deposit. 



H. — From Saddle Hills. 



27. Ferruginous black and white quartz. 



28. Chalcedonic quartz or agate [? from amygdaloid basalt]. 



29. Baked red and white fine conglomerate (a variety of so-called 

 quartzite) . 



30. A drift-portion of a black silicified substance like fossilised 

 wood. 



31. Quartz like No. 14. 



32. Siliceous deposit, probably a hot loater product. 



33. Jasperized rock, red and black, an altered clay or shale. 



34. Common opal, white with black streaks. 



35. Eed and white sandstone, altered. 



36. Hyalite coloured by iron (?). 



I. — From Bed of Gully near Bed Hill. 



37. Fine ferruginous sandstone or grit, apparently a Tertiary rock. 



Additional Bemarlcs. 



In this collection there is no granite ; but, by reference to Mr. 

 Himt's map, it appears that the whole of the country traversed by 

 him (as well as that previously described by Mr. Lefroy) extending 

 to near the meridian of 122° E. exhibits an abundance of granite ; 

 and that rocks of that class form the base of the whole region east- 

 ward of the Darling Eange. 



It would be interesting to compare the varieties of granite from 

 this region ; since Mr. Lefroy's descriptions lead to the conclusion, 

 that it is not all of like composition, nor of one age. 



Whilst admitting this, we cannot however adoj)t the opinion ex- 

 pressed by the latter gentleman, that the granite is the " primitive 

 crust " laid bare — an opinion which is at variance with the general 

 views of geologists of the present day, and is certainly not sup- 

 ported by some of the facts reported by him. The Protogine 

 which he met with in 30° 20' S., and 120° 40' E., as well as the 

 elvan dykes in 31° 27' S., and 119° 20' E., clearly imply metamor- 

 phisms or eruptions of a period subsequent to the formation of the 



