PHYSIOGRAPHY OF SOUTH GIPPSLAND. 463 



Meniman's Creek beds to the basaltic rocks of the Strzelecki and 

 Hoddle Ranges lias not yet been determined, but they are pro- 

 visionally classed by Mr. Murray as of the same epoch. 



Older Volcanic. 

 The silicious conglomerate, kc, and lignite beds just referred to 

 are overlaid by basaltic rocks, which are fully 200ft. thick in some 

 localities They are very much decomposed over large areas, as 

 between the Moe and Lang Lang and the latter and Tarwin 

 tributaries, as at Drouen and v^'arragul, along the main Gippsland 

 railway line, also surrounding Leongatha, on the Great Southern 

 line. They cover the large extent of country from near Grantville, 

 on^Western Port Bay, along the Lower Bass Valley, to Griffith's 

 Point, and constitute the principal formation on Phillip Island. On 

 the latter, at Pyramid Point, there are evidences of two flows, with 

 an intervening deposit of grit. In the Latrobe Valley, at Tarragon, 

 borings have disclosed several flows. They cap the silicious con- 

 glomerate in the Xeerim district, Tangil. and other affluents of the 

 Latrobe to the east, and occur at various localities along the flanks, 

 and in depressed areas on the watershed line of the Strzelecki 

 Range, as in the heads of the Tarwin and Narracan creeks 

 (Thorpdale), the valley of the Little Moreweil, Mirboo, and at 

 Calignee and Carrajimg, at an altitude of 1, 200ft. above sea level. 

 At Yarrason and Boolara they have been lowered by faultings to a 

 depth of nearly 900ft., and are, at these localities, covered by thick 

 deposits of gravels, sandy clay, grits, and bro^vn coal beds. There 

 are no defined centres of eruption observable within the area, but 

 the numerous dykes disturbing the Mesozoic strata, as at Korum- 

 burra, Bena, Powong, Tarwin River, and other localities, are 

 evidently lines of eruption for the lava flows, whose continuity has 

 been interrupted by subsequent enormous denudation and erosion, as 

 well as faultings. In structure the basalts vary from compact to 

 semi-crystalline, and partake frequently of the nature of oli\dne 

 dolerites, in which the principal constituents are Labrador felspar, 

 augite, and olivine, with much magnetite in some portions. Com- 

 pact basalts have been described by Mr. A. W. Howitt* from the 

 Narracan Creek and Moreweil River. 



The dykes examined by me at Korumburra, Bena, Jeetho Valley, 

 Cruikston. near Powong, in the Tarwin Valley, near Kilcunda, near 

 Trafalgar, and other localities, vary in texture from compact basalt, 

 plagioclase basalt, and ophitic olivine dolerites to olivine gabbros. 

 1 have elsewhere described their petrographic characters.! 



Miocene ob Older Pliocene. 

 In the Tangil River Valley are fluviatile deposits consisting of 

 coarse gravels, clays, and sands cemented with ferruginous matter 



* Prog. Kept. GeoL Sur., Vict., vol. iii., p. 175. + Special report Victorian coalfields, p. 13. 



