16 
EIDSVOLD GOLD FIELD. 
“ The country-rock round about Eidsyold consists of granite, which for the most 
part is medium-grained, of a pinkish-brown colour. Its coustituonts are orthoelase 
felspar, largish blebs of quartz, and small crystals of mica (biotite). The rock passes 
in parts into a fine-grained syenitic granite of a darkish colour, and contains hornblende 
in addition to mica. 
“ The reefs are situated in the granite country. They are running in vainous 
directions, though the majority of them have a north-west to north-north-west bearing. 
They lie very flatly in most cases, the underlie varying from 45° to 75°. 
“ All the reefs contain a certain amount of muudic ; and, as the water level has 
not yet been reached, the quartz is often of an ochreous or gossany nature from the 
decomposition of the sulphurets. It is probable that the reefs will be rich in sulphurets 
at a depth. 
“ Eidsvold, in many respects, somewhat resembles the Charters Towers G-old 
Field. The chief points of resemblance arc — the coimtry-roek, which in both places 
consists to a great extent of granite and syenite or syenitic granite ; in the flat underlie 
of the reefs ; and in the character of the gangue of the reefs, which consists in both 
places, to a great extent, of decomposed granite debris with veins of quartz. 
“ Comparatively small amounts of the sulphurets (pyrites and galena, &c.) have 
yet been met with in the Eidsvold reefs, owing, no doubt, to the fact that the workings 
have not yet reached beyond the action of atmospheric influences. The quartz, however, 
is often ferruginous, and contains a yellow ochreous material which has been produced 
by the decomposition of these sulphurets, which will be found to exist in large quantities 
in the reefs when the water level is reached. A few of the reefs contain a good per- 
centage of galena, a mineral of very common occurrence in the Charters Towers reefs. 
Very little copper ore occurs in the reefs. On the other hand, arsenical pyrites is of 
common occurrence here in some reefs. I did not meet with any zinc ore at Eidsvold, 
while sphalerite (zinc-blende) is of common occurrence at the Towers. 
“The field, as far as can be gathered from surface indications, is, with the 
exception of a few porphyry, and syenite dykes, singularly free from eruptive dykes. 
“ So far as can be judged from the work already done, the prospects of Eidsvold 
as a reefing district are very good. 
“ The field will soon have the advantage of a thorough trial, for two or three 
batteries will soon be on the field.” {Report on the JEidsDold Gold Field, by William 
H. Eands, Assistant Grovernment Geologist.) 
In the report above quoted, Mr. Eands gives detailed descriptions of the several 
reefs, and mentions the occurrence of tin ore (cassiterite) in one of them, associated 
with tourmaline, and of stibnite (sulphide of antimony) in another. 
Yield of Eidsvold Gold Field. 
Year. 
EEBF 
Stone Criislied. 
GOLD. 
Gold therefrom. 
Alluvial Gold. 
Total Gold. 
Tons . 
Oz. 
Oz. 
Oz. 
1887 
27 
84 
84 
1888 
7,768 
6,907 
ioo 
7,007 
1889 
15,933 
15,446 
150 
15,596 
1890 
20,910 
15,823 
no 
15,933 
Totals 
44,638 
38,260 
360 
38,620 
