The rich auriferous reef is the backbone of a long
narrow line of hill whose diameter ranges between 1,000 feet to 600 where
it is pinched. The lode strikes to the north-north-east with a dip of 47?
west. The angle of underlay, I may remark, greatly varies in these Gold
Coast reefs; some are nearly vertical (82?), others are moderately
inclined (20? to 50?), and others run almost flat. The richest part, not
including the broken-off ore, is from eighteen inches to two feet broad.
It is decidedly more than 'one to two hundred years old,' as reported home
by a scientific official on the spot. The 'coffins,' or abandoned native
diggings, must date from at least two centuries ago. The natives scraped
off the gold-bearing stone till the water drove them out. The formation is
upper Silurian or lower Devonian, a transition to gneiss, but not highly
metamorphic. No fossils have yet been found: if any exist they would be
microscopic. Where talcose it is bluish, and shows streaks of 'black
sand,' titaniferous iron. The grey sand washes to white. There are
pot-holes which have been filled with either a pudding or a breccia of
quartz. In places the gneiss has been so little changed by heat and
pressure that it forms arenaceous flags and shales.
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