58 E. 0. Teale: 



Howitt was a loose block, which had been brought to the old mine.. 

 As no more could be found in the neighbourhood, it was suggested', 

 that it might have come from Mansfield. 



The position of the present occurrence is shown on the map. It. 

 is onlv about a mile in a straight line, south-east from Fry's, and 

 less than half a mile south-west from the old mine. 



The rock is light-coloured, creamish, earthy fragments predomin-- 

 ating, but dark, almost black pieces sometimes somewhat cherty, 

 also occur. Rough stratification is noticeable, and the bed has a 

 defined dip and strike conforming with the enclosing rocks, llie- 

 outcrop is not continuously exposed at the surface, and has the- 

 appearance of being broken and dislocated. The rocks in general, 

 in this zone are much disturl^ed. The pliosphatic breccia, howevei', 

 can be traced at intervals along a distance of aliout 1-30 yards, in a. 

 north-west to south-east direction. 



WavoUite is abundant in thin seams along some of the joint 

 planes, and an analysis of the surface rocks shows that it is an* 

 impure aluminous phosphate, containing only about 7% of ^2^5. 

 This may represent leached material; at any rate, it would be un- 

 wise to say that it represents the composition of this rock at a 

 depth. Lithologically, the material does not resemble the Mans- 

 field phosphate rock, which is not a breccia. The organic remains 

 are imperfectly preserved crustaceans of the character of phyllopod- 

 like forms, Avhile those of Mansfield have been referred to as prob- 

 ably Salterella, thus differing also organically. An account of this, 

 phosphate deposit has recently been published. 2 



Since Tefrar/raptns has been recorded at Mansfield, it would' 

 appear that both Lower and Upper Ordovician graptolite-bearing 

 rocks are closely associated. At the Howqua, the only fossils in ther 

 associated beds are graptolites and occasional brachipods, whichi 

 may l>e either Upper Ordovician or Silurian, and the phosphate- 

 deposits are definitely interbedded with these. 



In order to test the relationship of the phosphate deposit to the 

 surrounding sediments, the writer and his father spent a couple of 

 days with pick and shovel putting a trench across the outcrop, the- 

 result of which was to prove conclusively that the phosphate breccia 

 is interbedded Avith the surrounding graptolite-bearing strata. The' 

 accompanying section illustrates the relationship. 



Ernest W. Skeats and E. O. Teale, Aust. Inst, of Mining Ensineer-s, Pron. 

 New Series, No. 32, 1918, pp. 155-165. Fig. 4 is from a block lent bjr 

 the Aust. Inst, of Mining Engineers. 



