472 Notices of Memoirs — Victorian Alkali Rocks. 



olivine basalt, while at the Hummocks north of Casterton another 

 trachyte dyke similarly penetrates a vent or small flow of olivine 

 basalt. Among the ejected blocks from the earlier members of the 

 Pleistocene newer basalts of Lake Bullenmerri, near Camperdown, 

 are some consisting of essexite and containing analcite. In the 

 western district of Victoria clear evidence of comparatively recent 

 elevatory movements is noticeable. No definite faults have yet been 

 proved, however, and the normal basalts are much more widely 

 spread than the alkali rocks. In view of Harker's generalization as 

 to the close correspondence between the occurrence of alkali rocks 

 and elevatory movements of the plateau type, generally accompanied 

 by faulting, the above reference to earth movements is pertinent. 

 Practically no folding movements are known among the Tertiary 

 rocks of Victoria, while plateau movements, generally of elevation, 

 sometimes of depression and accompanied by faulting, are widespread. 

 Near Omeo and Mansfield, where faulting has been demonstrated or 

 inferred, the highly alkaline types of nepheline phonolite are developed, 

 but the widespread plateau movements in Victoria are more specially 

 associated with the occurrence of the normal basalts. The alkali 

 trachytes and allied rocks are intercalated between an older and 

 a newer basalt series, are developed only sporadically at certain 

 centres, and, as at Macedon, are closely associated in the field with the 

 newer basalts as rocks of slightly greater antiquity but belonging to 

 the same volcanic period. 



References to Liteeature. 



1. HowiTT, A. W. Eep. Min. Dept. Vict., September, 1890 ; Eep. Min. 



Dept. Vict., March, 1890 ; Trans. E. See. Vict., vol. xx, 1884. 



2. Skeats, E. W. Aust. Ass. for Adv. of Science, Brisbane, 1909, Presidential 



Address to Section C ; Aust. Ass. for Adv. of Science, Sydney, 1911. 



3. Griffith Taylor, T. Com. Bm-eau of Meteorology, Bulletin No. 8, 1911. 



4. Fenner, C. Proc. Eoy. Soc. Vict., N.S., vol. xxv, 1913. 



5. Gregory, J. W. Proc. Eoy. Soc. Vict., N.S., vol. xxv, 1901. 



Skeats, E. W., and Summers, H. S. Geol. Surv. Vict., Bulletin 

 No. 24, 1912. 



6. Summers, H. S. Aust. Ass. for Adv. of Science, Sydney, 1911. 

 66. Dennant, J. Aust. Ass. for Adv. of Science, Adelaide, 1893. 

 66. Hogg, E. Proc. Eoy. Soc. Vict., N.S., vol. xii, 1899. 



(9) On the Origin and Relationship of the Victorian Kainozoic 

 Alkali Rocks. By H. S. Summkks, D.Sc. 



ALKALI rocks of Kainozoic age occur in Victoria in the Macedon 

 District, near Coleraine and Carapook in the Western District, 

 and in the neijihbourhood of Omeo and Mansfield in Noith-Eastern 

 Victoria. Ejected blocks from the volcanoes near Camperdown have 

 been described as essexite, and a simiLir type, also proliably ejected, 

 has been found near Kvneton. With the exception of the occurrences 

 of Omeo and Mansfield all these alkali rocks are closely associated 

 with the Upper Kainozoic calcic basalts, and the field relations are 

 such that there is little doubt that the alkali rocks and the basalts 

 are genetically related. 



Numerous analyses (mainly unpublished) have been made of 

 Victorian basalts, and these show that they are fairly normal in 



