B\ in i: REV. J. mil Nic OURBAV, 2'.V.\ 



II. On a microscopic exaDiination the "blue metal" if found 

 to be •« true olivine bftialtftnd an "! ( l lava How that filled up an 

 ancient river bed. 'I'll" point of eruption wan near Bwatohfield 



No dot i Id, pagee ••'•ii*l chapters of the geological record are mi 

 but the foregoing is my reading of the bUtory of Batbur I m 



w lit i <•!! iii her rocke. 



EXPLANATION OP PLATES, 



Plate kiv. Reproduced frommiorophotographsol thin slices oi Bathurst 

 baialti. Fig. I, xfiO, hIiowh the general structure of the basalt at Pinnae Ic 

 Hill. To thr right two olivines are seen, traversed by lerpentinoui Lines of 

 decomposition The lower olivine represent! one ball of a crystal, tin: 

 other ball <>f erhiob floated away to a considerable distance. The lath 

 shaped felspars show a tendency to stream round the larg< crystals. Pig 

 2 is a basalt from Mt. Pleasant, enlarged 60 diameters. A \n-.\y eharactei 

 istio olivine occupies the right of the figure. The dark lines following the 

 cracks are bright green decomposition products. Ontheothei sni< ; oi the 

 figure there is a large plagioclaie, containing some inclusions of the base. 

 i [g :; Iiowh a thin slice of basalt iiotn tin- quarries at Bald Kills, enlarged 

 00 diameters. At tin: top oi this figure there is a portion ot s micro 

 porphyritic olivine, and Home distance below a basal section <>f augifr 

 'JIm:m<: and other large crystals are set in a micro-crystalline ground mass 

 The lath shaped felspars .show a decided flow. The magnetite is very 

 abundant as block grains. Pig. 4, x 90 diameters Under this magnifying 

 power magnetite shows clearly. The large olivine in the tipper portion of 

 tin: figure shows inclusions of this mineral, "in: being a perfect cube. The 

 other large crystal is an Idiomorpbic augite. Between these two i 

 a streaming of the felspars is very noticeable It will be remarked that the 

 felspai have Incomplete terminations ami sometimes bifurcate at either 

 extremity. Pig. 5. In the lower left band portion of this figure a large 

 augite is seen partially penetrated by two plagioi la ■>■ prisms. The smaller 

 lath-shaped felspars flow round the augite in an Interesting manner. 

 Magnetite is scattered through the slide. The two clear ipaoes at the top 

 are olivines. The thin slices in Figs i ami were ':nt, from basalt used for 

 kerb-stones in Bathurst, and quarried on tin. Bald Hills a few miles south 

 of the city. 



Plat* xv. Pig, I shows ;j, vein oi granite Intruding a much altered 

 sedimentary rock. Between Brewongleand Locksleythi po ed 



