74 E. 0, Teale: 



ion zone. This belt bears the record of a long succession of tectonic 

 Tolcanic and sedimentary events ranging practically throughout 

 .the Palaeozoic period, starting with Cambrian and closing with 

 Lower Carboniferous. There are probably three distinct periods 

 of igneous activity represented, namely, Cambrian, Lower Devo- 

 nian and LowTT Carboniferous. A succession of powerful fold and 

 fault movements along a line varying between N.N.W. and N.W. 

 .acting at intervals throughout this period, has impressed especially 

 in the older formation, some marked structural features in the 

 form of intense folding, crumpling and crushing. A general 

 parallelism in strike as a rule exists between the different forma- 

 lions, and the evidence of unconformities has to be considered very 

 carefully. The problems of any portion of this extensive and 

 mountainous belt should take note of the general features of the 

 ^lole area as far as possible, but, unfortunately, much of the 

 region is still very imperfectly known, and some of it has never 

 been examined geologically. The Wellington area forms the south- 

 ern end of the belt, and rises abruptly from the northern cdo:e of 

 the great Gippsland Plains, a little to the north of Heyfield, and 

 forms a part of the great Central Highlands of Victoria. 



The Mansfield region lies near' the northern end, across the Main 

 Divide, not far from the border of the Hio:hlands with the northern 

 plains. The length of the w^hole belt is about 100 miles, with a 

 width up to about 40. ^luch of it is covered by Upper Palaeozoic 

 sediments and igneous rock, but extensive denudation has in places 

 stripped off this covering, and laid bare the older rocks, notably 

 near Mansfield, in the Fowqua Valley, and also in the Wellington 

 and Dolodrook Rivers. The need for further work in the first and 

 •second localities will be explained later. The particular features 

 of the Palaeozoic rocks of the Wellington area will now be taken 

 in order and some reference made to related occurrences elsewhere 

 in Victoria. 



Pre-Ordovician Series (Heathcotian)— Under this division 

 there are three distinct groups of rocks : — 



(a) Serpentine Pre-Upper Cambi'ian. 



(b) Trilobite Limestone Upper Cambrian 



(c) Garvey Gully series of Sediments 



The general occurrence of this series is shown on the map of the 

 W^ellington region, and the accompanying Sections (Map No. 1 and 

 Sections 1 and 2). It will be seen that the rocks oi this series occur 

 as a long, narrow curved inlier striking generally in a north- 

 westerly direction, Avhich is the grain or trend of the whole structure 



I 



