330 



and Pearce ' 10) describe albitites from the Northern Urals, 

 where they are associated with gabbro. In these rocks the 

 albite is developed intergrown with a little quartz. 



It is to be noted that both these occurrences are associated 

 with more or less basic rocks, e.g., in the Sierra Nevada with 

 serpentine, and in the Northern Urals with gabbroid masses. 



In Australia rocks of this nature have been found in 

 Western and South Australia. Maitland (11 ' described a 

 pegmatite from the Pilbarra region. The constituents appear 

 to be albite, quartz, garnet, and cassiterite. From Eyre 

 Peninsula, South Australia, R. L. Jack ( 12 -> describes dyke 

 rocks of aplitic habit consisting, essentially, of albite with 

 small amounts of quartz, muscovite, apatite, and magnetite. 

 From the descriptions given, the albite evidently possesses the 

 peculiar chequer structure. In one instance there is a remark- 

 able association of wernerite with the albitite, the scapolite 

 being developed in long prismatic crystals. 



The association of the Western Australian albitite is with 

 granite, whilst the Eyre Peninsula rock is intrusive into 

 metamorphosed sedimentary beds, but granites are developed 

 at hand. 



A partial analysis of an albitite from Cape Willoughby 

 has been made. This is tabulated below, and for comparison 

 the analyses of a number of other albitite rocks are listed 

 with it 





I. Sierra 

 Nevada. 



II. N. Urals. 



III. Pilbarra. 



IV. Eyre Pen. 



V. Cape 

 Willoughby. 



Si0 2 



66*54 



66-09 



68-36 



66-13 



68-39 



Ti0 2 



n.d. 



0-23 



0-07 



0-31 



n.d. 



A1 2 3 



n.d. 



18-85 



18-74 



19-92 



n.d. 



Fe 2 3 



n.d. 



0-91 



— 



0-60 



n.d. 



FeO 



n.d. 



— 



1-15 



0-19 



n.d. 



MnO 



n.d. 



— 



0-45 



— 



n.d. 



MgO 



0-77 



1-53 



0-54 



0-12 



n.d. 



CaO 



0-43 



1-09 



0-39 



0-57 



0-65 



Na 2 



10-28 



LO-84 



10-22 



10-83 



11-22 



K„0 



0-89 



0-48 



0-07 



1-02 



0-21 



h;o 



n.d. 



1-17 



0-03 



0-44 



0-45 



pa 



n.d. 



— 



— 



0-09 



n.d. 



I. H. W. Turner: 17th Ann. Report F.S.G.S., 1895-6, p. 728. 



II. Duparc et Pearce: Compt. Rendu., 140, 1905. 1614. 



III. A. Gibb Maitland: Bull. 40, Geol. Surv. W. Austr., p. 100. 



IV. R. L. Jackd3): Bull. 3, Geol/ Surv. S. Austr.. p. 16. 

 V. C. YVilloudibv albitite. 



(10) Duparc et Pearce: Compt. Rendu., 140, 1905, 1614. 



(11) A. Gibb Maitland: Bull. No. 40, Geol. Surv. W. Austr., 

 pp. 100-102. 



(12) R. L. Jack: Bull. Xo. 3, Geol. Surv. S. Austr., pp. 15, 16. 



(13) The abnormally high content of Na 2 (13 - 48%) reported 

 for the Miltalie albitite casts suspicion on its reliability. 



