| dc.description.abstract | In a study carried out at the Fifteen Mile Stream gold district, Halifax County, to document the distribution, character, and composition of gold in till around the former gold mines, 21 sample sets of A, B, and C horizon material were collected from the soil profile. Sampling was conducted at 10m intervals in till exposed by two trenches which are oriented perpendicular to the strike of both the veins and host strata.
Geochemical analyses for gold, silver, lead and arsenic were performed on samples of the B horizon and on 4 size fractions of the C horizon. Samples of the A horizon were analyzed for gold only.
The >2f fraction of the C horizon with a mean gold content of 217 ppb contains higher concentrations of gold than other size fractions and horizons analyzed.
The gold occurs as foliated flakes which are morphologically similar to gold particles from the tailings of the mine. That the gold is not far-travelled is evident from the lack of surface striations or other deformational features indicative of abrasive transport.
Microprobe analyses of gold from the till gave unexpected compositions which differed significantly from those of the presumed source. Gold from the till has an average composition of 69% copper, 10% gold, 9% zinc and 1% silver as compared with gold from the mine tailings which average 91% gold and 9% silver. This discrepancy in composition between the primary and secondary gold is thought to be due to a hydromorphic redistribution of gold in the till.
On the basis of correlation analysis performed on the geochemical results, and compositions determined using EMP analyses, gold, arsenic, copper, and zinc are considered the most important elements to be analyzed in pedogeochemical exploration for gold mineralization in rocks of the Meguma group.
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Pages: 82
Supervisors: Marcos Zentilli | en_US |
