UMM GARAYAT – Gold (50% Gippsland)

Location

The Umm Garayat gold prospect is the most famous ancient mine known in the south-western part of the Eastern Desert, located 210km southeast of Aswan at Latitude 22°34'28.2"N and Longitude 33°22'33.7"E.

Umm Garayat is an ancient mine that was exploited by the ancient Egyptians and Romans. The old workings consisted of large excavations over a strike length of 260m. A shaft sunk in 1902 intersected the ancient workings at a depth of 23m and it was noted that the workings continued deeper to the north.

The Nile Valley Company worked the mine for a number of years commencing in 1901. The deposit was worked from eight vertical and inclined shafts and winzes linked by levels at inclined depths of 32m, 60m and 96m. A five head battery was reported as having been erected in 1904. The mine was famous for having produced some very rich ore with one shoot having produced over 15,000oz from 1,506 tons of ore.

The thickness of the reef varied from the width of the drive to a few millimetres but averaged 660m throughout the mine. The gold content ranged from 7.75-155.5g/t, with average values on the order of 12.1-13.7g/t. In the upper levels, the vein averaged 0.76m in thickness and 10.85g/t. The average grade of the mine was 7dwt (11.9g/t).

Umm Garayat gold mineralisation is confined to a single quartz vein trending north-northwest and dipping 60°-80° to the west, more or less concordantly with the schistosity of the enclosing rocks. The host rocks are quartz-sericite schists (meta-mudstones) with layers of graphitic schist which occur as a lens within andesitic tuffs and lavas metamorphosed to the greenschist facies. The area is strongly schistose and lineated fine grained grey dominantly intermediate volcanics.

There is evidence of widespread pitting over the entire area around Um Garayat and of placer workings to the west and northwest.

Structural mapping will be completed to determine the geometry of the known mineralisation in the old workings. This will be used to site RC holes to test for down plunge extensions. RAB drilling will be used to test for shear structures beneath the wadi sediments.