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UM GARAYAT –
Gold (50% Gippsland)
Location
The Um 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 22o 34' 28.2"N and Longitude 33o 22' 33.7"E.
Historical mining
Um 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.
The thickness of the reef varied from the width of the drive to a few millimetres but averaged 26" (0.66m) 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).
Geological setting
Um Garayat gold mineralisation is confined to a single quartz vein trending north-northwest and dipping 60o-80o 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.
Exploration
Exploration completed by Gippsland has included geological mapping, re-sampling of all of the existing trenches and the excavation of two new trenches.
UM GARAYAT REGIONAL
Location
The prospect includes a number of historical workings around the Um Garayat region. It includes the localities of Wells area E, Wells area F and Ivanov.
Previous exploration
Regional prospecting by the Nile Valley Company in 1905 identified a number of bedrock workings away from the larger ancient mines. It is most likely that all of these occurrences were known to the ancient miners. At the Ivanov working the Nile Valley Company sank at least three shafts and may have processed small parcels of ore through the Um Garayat mill. It is not known what work was completed at Wells areas E & F.
Geologic setting
The Ivanov occurrence is located on the southerly extension of the main Um Garayat structure. Areas E & F appear to be on minor splays.
Exploration
A programme of drill testing has been proposed for the areas.
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