Dear John,
I am sure you are right re Gairloch v. Sandlodge geol. since I know you
have good knowledge of Scotland - I am not familiar with Shetland, and my
interest I must admit is the corporate history of this specific place and it's
operators. I must did out a geol. map of Shetland though so I may at least
a little informed!
1789/90 seems to be when what you indicate came about (apparently 12t sent
to Anglesea - though the true tonnage will probably never be know), but by
1807 the mine was deemed not worthwhile. Fe seems to have been a
significant 'item' when the mine was reopened in 1879, yet not that long after
notable production of copper ore came about (700t plus), but no mention of any Fe
production. G&L's mention of malachite can only refer to the pre 1807
working close surface opers. of course, since the mine seemingly did not work
between 1807 and 1879 - the latter date when 'deep' mining was pursued -
when seemingly all was sulphide mineralisation from then on. Thankyou for the
additional info. John, all helps paint a picture of the place.
I believe all the operations were clear and legitimate at Sandlodge, and
there were never Corporate 'going's on'.
Has anyone on the List been to Sandlodge?
Regards, Bernard
In a message dated 31/07/2011 08:17:42 GMT Daylight Time,
[log in to unmask] writes:
Just a quick geological interlude! Difficult to compare this deposit to
e.g. Gairloch because Sandlodge (so far as I am aware, and I've read odds &
ends about it over the years) is an epigenetic vein deposit with quartz,
carbonates, chalcopyrite, tetrahedrite and hematite - whether the latter is
primary or secondary I don't know, but the oxidation-zone appears to have
been well-developed as the site was famous for its malachite, which earned it
a mention in Greg & Lettsom's Manual of the Mineralogy of Great Britain and
Ireland (1858). They say: "In very fine acicular crystals, almost equal to
the Siberian specimens, at the old copper-mine, Sandlodge". Praise indeed!
They also report native copper from there.
Regards - John
|