147 
PHOSPHATE OF IROH AHD OTHER MINERALS, 
WHITFIELD DISTRICT. 
By A. AI. Howitt, Field Geologist. 
In 1905, on my return from a visit to Whitfield^, I submitted to the 
Geological Survey laboratory a ferruginous specimen showing the 
presence of phosphoric acid, and the result of the analysis was 10 per 
cent, of phosphoric anhydride. Subsequently the ridge, from which the 
specimen came, was prospected and the lode discovered. 
This lode was found on a main ridge between Stoney Creek and the 
King River, and has been traced for 150 ft. in length by several small 
prospecting cuts. The lode strike is W. 33° N., and its dip west 
to nearly vertical, conformable to western dipping sandstones and slates 
of Upper Ordovician age. Four chains east and higher up the spur 
there are eastern dipping strata, which are the northerly continuation 
of the Mt. Avis turquoise beds, from which Upper Ordovician grapto- 
lites were formerly recorded. 
An interesting feature is that on the eastern side of the anticlinal 
fold at Mt. Avis, Whitfield, the turquoise (phosphate of alumina) 
occurrences are secondary to, but nearly always associated with, iron 
pyrites in small fissures and nodules, whilst in the same beds further 
to the north, and on the other side of the fold, there appears to be no 
pyrites or turquoise, but a combination of iron and phosphoric acid, 
occurring as a vein or lode of basic phosphate of iron (dufrenite)^. 
As at present exposed the lode varies from a few inches up to 
1 ft. in width, and some of the richer portions yield up to 31.54 per 
cent, of phosphoric anhydride (analysis No. 413). The top or 
southerly prospecting cut is 4 ft. across the strata, and here the rich 
ore is only narrow and pinching out going south. The middle cut 
26 ft. further to the north-w’est is 5 ft. across the strata, and 3 ft. deep, 
proving 2 in. of rich ore and 6 in. of poor ore bounded by slate and 
sandstone showing traces of phosphates. The main cut and the 6 ft. 
shaft are 120 ft. further to the north-west, and here up to 1 ft. of ore 
has been proved. 
At present the amount of rich ore is too small to be of commercial 
value as a phosphate, but further prospecting may prove other ad¬ 
jacent veins. The ore might be of value as a pigment, as when ground 
it produces a dark-green colour, with a moderate covering power (see 
analysis No. 400). The occurrence is of value, as it proves that rich 
phosphate of iron in lode form may occur in other localities in Vic¬ 
toria amongst the extensive areas of Upper Ordovician rocks, which 
are in many districts little known from a mineral aspect. The ore is 
itself of interest, having been determined by complete analysis (No. 
413) as indicating dufrenite (basic phosphate of iron), new to the 
list of Victorian minerals. 
Some Mineral Occurrences at Whitfield. 
At Mt. Pleasant, about 8 miles to the south of the township, an 
examination was made of a series of Carboniferous strata nearly horizon¬ 
tally bedded, and dipping 3° south-east. (Fig. 55.) The mount shows 
a series of steep cliffs of sandstone and thin impure limestone beds, 
relieved by short slopes where red to brown mudstones outcrop on the 
northern face, very similar to the beds at Mt. Battery, in the Mansfield 
^ Edi-Myrhee Turquoise Belt, by A. M. Howitt, Rec. (leol. Surv. Viet., Vol. I, Pt. 4, p. 239. 
* See appended analyses. 
