Palaeozoic Geology of Victoria. Ill' 



The rocks tlirou<2:liout tlie gold field, iii\ addition to tli'-.'ir sheared' 

 features, are frequently somewhat cherty, and on the whole are light-- 

 coloured, varying from whitish to creamish, with some superficial 

 ironstaining along tlie joints and bedding planes. This light 

 colour may be due to extensive bleaching Avithin the zone of 

 oxidation, for occasional loose fragments of black chert are to be ■ 

 found, and there is one occurrence of black chert in situ in the bed . 

 of Lady Torr Creek. 



Special attention was given to the region of the old gold mines, 

 tecause it was here that Mi-. E. J. Dunn described the occurrence- 

 of " Heathcotian " (24), as well as Oi-dovician. Mr. Dunn observes 

 that "the Tara Range is remarkable that within a mile of the 

 Micawber lease there are three distinct series of rocks carrying 

 auriferous vein-stones." 



The three series referred to are Heathcotian, Ordovician and 

 Lower Devonian, and the separation of the first two series appears 

 to be based on lithological differences only, particularly the supposed > 

 significance of cherts and jasperoid rocks as a distinctive character- 

 istic of Heathcotian; but here again, as in the Wellington district 

 and elsewhere, this feature loses its significance, for at locality 6, 

 north of Lady Torr's Creek, the author found Upper Ordoviciap- 

 graptolites in light coloured cherty rocks, and in general these • 

 rocks are so intimately associated with the more normal sediments, 

 which also yield Upper Ordovician graptolites (locality 18), that 

 there is no valid reason for separating them. 



Turquoise. — A little turquoise Avas found in an old adit in the ■ 

 basin of Lady 1'orr's Creek. It occurs chieflv along the joints, 

 irregularly distributed in a light-colored felspathic sandstone, 

 and though of interest as another example of its wide distribution 

 in the Ordovician, the specimens obtained did not afford much- 

 promise from a commercial point of view. 



Gossany Ironxtniie .- — Towards the northern end of the area under 

 consideration (Fe 6 on map), there is an ironstone outcrop, consist- 

 ing chiefly of limonite. It is roughly elliptical in shape, measur- 

 ing about 3 chains in a north and south direction, and 1^ to 2' 

 chains across. Much of the limonite is hard and massive, but 

 some contains quartz, and broken up sedimentary rock. The limits 

 are rather indefinite, the deposit passing out into ferruginous shale 

 much crushed and jointed. The strike of the strata is about 

 N.N.E., and the dip appears to be easterly at a high angle. Anotlier 

 similar outcrop occurs about 30 chains to the S.S.W., on the fall to 



