Peter,
Whilst I accept that Richard Scrivener solved the problem of the venticular
veins of ore in Combe Martin, the fact that he found little evidence of
Falhers or Falerz ores on existing dumps does not in any way surprise me.
The dumps are of course from 19th century mining operations, the ores being
from a much deeper source and would cover any earlier working dumps from
shallower deposits.
I believe it to be significant that when I carried out the excavations
around Harris's Mine in Combe Martin, and specifically into the dumps to a
depth of 4m +, dumped waste clearly had signs of dull grey ores and
tetrahedrites. To state that tetrahedrites are relatively rare in Combe
Martin is complete speculation. The bottom line is of course that
satisfactory excavation according to IFS methodology has NOT previously been
carried out in Combe Martin. I find this speculation further unqualified in
that until the work recently carried out by Bastian Asmus, as far as I am
aware, no ores from Combe Martin have been satisfactorily analysed (with the
latest equipment and techniques) to offer definitive results as to their
composition.
It may be that historians, and indeed geologists, have to recognise, that
until factual results are obtained through systematic archaeological
excavation of a high standard, it is dangerous and indeed somewhat foolhardy
to base ones premise on documentary history, or searching the surface of
19th century dumps for evidence. I guess your work down at Bere Ferres may
be teaching you that.
Trevor
----- Original Message -----
From: "Peter Claughton" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, April 14, 2008 4:07 PM
Subject: Re: Falhers or Falerz Ores.
> At 15:00 13/04/2008, John Mason wrote:
>>Many Central Wales veins are multiphase. First active in Devonian times,
>>there were phases of reactivation in the Carboniferous and Permian. Later
>>mineralisation along existing and new fractures deposited galena that is
>>pretty much inclusion-free and hence 5-10 times less argentiferous than
>>the
>>earlier stuff. Thus, some mines were getting 20-30oz Ag per ton whilst
>>others just managed 3 to 7. I wonder if a similar pattern exists in the
>>Combe Martin mining district?
>
> John,
>
> The Combe Martin deposits are probably syngenetic in origin. Richard
> Scrivener, late district geologist with the BGS, is of the opinion that
> they were laid down in the Devonian period on a contemporary seabed,
> subsequently overlain with sediments and subject to folding before being
> remobilised by groundwater movements in later north-south cross-courses.
> The tetrahedrites are relatively rare at Combe Martin - Scrivener failed
> to find much on the dumps - compared with the later mineralisation at Bere
> Ferrers in the Tamar Valley.
>
> Peter
>
> ______________________________________________
>
> Dr Peter Claughton,
> Blaenpant Morfil, nr. Rosebush, Clynderwen, Pembrokeshire, Wales SA66
> 7RE.
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>
> Research Fellow - School of Geography, Archaeology and Earth Resources
>
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>
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