The Times today also notes that a large deeposit of high grade coking coal haas been discovered under the Solway adjacent to Haigh pit with a potential to raise 3 million tons a year!
The firm involved Riverside Energy, are hoping to raise £13 million to get the project started.

Based on historic productivity in this coalfield that's at least 5,000 jobs then. ::) - but seriously, the presence of a high reserve and good quality has long been known, and only 25 years ago Geevor made the same embarassing claims when they attempted to go for it.

Thanks for that John_L. I see from the RNS that holes 2 and 3 were 1.3 km NW of hole 1. That would be somewhere around Roughside. Hole 4 was then 2 km west of 2 and 3 presumably somewhere around Nentsberry. I would have expected the sites to have been posted along with the planning permission but can't find any trace of that on the web. It would be nice to know so we can see which veins they were looking at. My guess at present would be BH 1 Scaleburn, BHs 2 & 3 Gudhamgill, and BH 4 High Raise. That would fit in with the possible extension of the drilling into Northumberland.

The remarks about the mineralisation being above and below the Whin Sill are very interesting. Dunham's best guess for this area was that the Whin must be below the Lower Little Limestone (1990 Fig 8 p 47) on the basis of Rampgill Shaft. That suggests there is some sulphide mineralisation in the lowest limestones in line with MINCO's model of the NPO and in marked contrast to what was seen at Allenheads (see BGS BH database and my earlier post). All very fascinating for an old timer like me who now only goes underground when he takes a ride on the tube!

Dave Greenwood

Also, does anybody know exactly which veins they've tried? Rampgill presumably from the location of the first site but anywhere else specifically?

From an email from the geologist involved at the meeting, they had 'permission to explore the Rampgill, Scaleburn & Guddamgill structures.'
'Our drilling is designed to intersect the plane of the vein at considerable depth below the old workings and will be collared in excess of 100m to the north of the vein outcrop. The holes will pass through the horizons mined in the past a considerable distance to the north of the old workings; in the case of our first hole in the order of 150m to the north of the old workings in the Rampgill Vein.'

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I was interested in the remarks regarding Alllenheads mine, since I was told by a mining lecturer that British Steel did not drill the area thoroughly enough , and were he'll bent in setting up the mine.
They apparently took the view that the mine had been one of the biggest ore-producers in the Pennines and so as fluorspar was the main gangue mineral, then obviously there must be a lot of it.
Diamond drilling cores my friend told me did not fit into this initial assessment!
Underground the miners were very disheartened. They often reffered to it as a limestone mine.
As I remember it they simply did not have enough pump capacity to bottom the Great Limestone, and most of their explorations took place ontop of it with very low ore yields.
Perhaps more drilling, and thought, before mining and we might have had a successful mine here.

The full history of the Allenheads boreholes can be found in my article in The Friends of Killhope Newsletter No 79. Briefly Allenheads No 1 was drilled on a possible shaft site close to Gin Hill Shaft before a decision had been made to have an incline. When the borehole reached the Whin Sill an arrangement was made with Sir Kingsley Dunham, then Director of IGS, for the hole to be continued to the pre-Carboniferous basement using IGS funds to provide a comparison with Rookhope. Allenheads No 2 was drilled on the same basis to provide an accurate stratigraphic sucession for beds above the Firestone Sill. Logs of both holes are in the public domain in the BGS Borehole Database as NY84NE/4 & 10 and NY84NE/5 & 11. Neither borehole was drilled for exploration.

Fluorspar exploration at Allenheads was based on the evidence from around 50 Bargain Books (1845-1897) which contained records of weekly inspections of the mine workings. These showed that there was a very large fluorite oreshoot at the south end of Henry's Vein extending up into the Slate Sills that appeared to be very similar to descriptions of Groverake. The BSC workings never reached that point and too much time was wasted exploring Allenheads Old Vein despite the fact that the Bargain Books and mine plans showed that the main mineralisation on Old Vein was in the form of replacement flats in the Great Limestone and that the ground was in any case worked out. Although the flats contain minor amounts of fluorite, in general in the NPO the veins adjacent to flats are not fluorite rich and are not a target for fluorspar mining. The oreshoot at the south end of Henry's Vein has never been tested and Dunham regarded this area as one of the best remaining prospects for reworking old lead workings for fluorspar if that can be done in line with modern Health & Safety legislation.

Dave Greenwood

MINCO Borehole sites.

The sites as originally proposed (to 10 m) were

1. NY 7940 4418 - drilled as CA-001
2. NY 7927 4435 - not yet drilled see link below.
3. NY 7866 4516 - driled as CA -002
4. No details as yet - but drilled as CA-004

CA-003 (which gave the best results) was an additional borehole not in the original list at NY 7890 4541 to the NE of CA-002 towards the County Boundary.

Note the actual locations may have changed by a few metres once the rig was on-site.

http://www.cwherald.com/archive/archive/nenthead-boreholes-work-extended-to-march-20121207401241.htm 

Dave Greenwood

Thanks Sopwithfan,
Your information confirms what I was told. British Steel should have drilled the area properly and after evaluation prepared for mining.
In order for this to take place properly either the adit should have cleared for drainage or they should have been prepared to have enough pump capacity to bottom the Great Limestone.
In the latter days I understand they had reached Henry's Vein, but were frustrated water and bad air.
One thing is certain the Minco approach is the correct one

Sorry John, I don't agree. Until the mid-1970s almost all the fluorspar produced in the NPO came from the re-working of old lead mines and was based on old mining records. Think of Stotfieldburn, Stanhopeburn, Blackdene, Groverake, Whiteheaps, Cambokeels, Burtree Pasture, etc. Dunham's Survey Memoirs in 1948, 1952 and 1990 are full of examples. After that it was a case of extending into virgin ground eg Whiteheaps in the Great Limestone, the lower levels of Groverake and Blackdene in the Whin Sill. Only Redburn and Frazer's Hush cut genuine new ground. With an oreshoot up to the Slate Sills in Henry' Vein there was no need for BSC to go below the Great Limestone in the first few years. The mistake was to waste time on Old Vein for the reasons mentioned before.

Dave Greenwood

Sopwithfan,
To work stopes in the GL you have to access from below it, and then drive rises up into it and drop the ore down into the level below it.
All the North of England mines were worked by this method, by not having the pump capacity to maintain a dry level, below it,then there was no way it could ever be successfull.
All the old lead mines which made successful fluorite mines could remove their water one way or another.
I am surprised you cite Burtree Pasture, where given access to the GL and reasonable pumping capacity, only a relatively small amount of fluorspar was raised, especially given the vein length ahead of them.I can only assume the ore values did not justify the mining costs.

John - I think we are straying a long way from MINCO with this discussion so in fairness to others I will open a new thread on the topic of Henry's Vein at Allenheads tomorrow or Saturday.

Dave Greenwood

John, I have posted a reply to your 20:48 post of 30/5/13 under the Allenheads BSC Mine thread.

Dave Greenwood

The point I raise is a simple one, MINCO are relying on Borehole evidence to make their mining decisions.
Whereas British Steel, made judgements not on core values, but based only on historical written evidence. The lack of actual factual information was compounded by not calculating the necessary mining costs.
Minco, as a small unsubsidised, company I am sure will not be making the same mistakes.

John,
There was no lack of factual information. The mine plans were coloured according to the geology. We had a stope section of Henry's Vein that also showed the stratigraphy. Last but not least we also had information about vein widths and stratigraphic horizon from hundreds if not thousands of weekly inspections by John and William Curry and later by John Ridley in the Bargain Books. Drilling would have added nothing to this.

MINCO's search for virgin lead-zinc orebodies is an entirely different proposition to fluorspar exploration and you are not comparing like with like. Incidentally, on the basis of their Irish deposits we can look forward to a huge number of further boreholes being drilled if they find anything worth working up to JORC compliant reserve status.

Dave Greenwood

Comparison with Irish Zn-Pb deposits fails on one very simple premis. The age of the host hocks in the Northern Pennines generally post date the mineralizing events in Ireland where the host limestone sequence is Courceyan to early Arundian in age (355-335Ma) and mineralization generally (at Navan, Silvermines, Tynagh, Lisheen and most other prospects) was emplaced in the same time period. In the NPO only the basal Basement Group (Roman Fell Beds) and the overlying Lower Orton Group are Chadian to Arundian and dominated by clastics and mud rocks and thus unsuitable for Irish-type Zn/Pb deposits.

Sorry to disappoint but there really is no chance of Irish type mineralization in this drilling only epigenetic replacements coeval with the rest of the NPO around 280Ma.

But good luck to Minco anyway, we could do with a new discovery.

Minegeo,

In that case what do you make of the following paragraph taken from MINCO's RNS of 2/11/2012:

"The initiative to explore the North Pennine Orefield has been under consideration by Minco for a number of years and was developed independently by Minco's technical team of Peter Tyler and Terence McKillen who successfully identified the potential for and led the discovery of the Pallas Green zinc-lead deposit in Ireland. The North Pennines is likely to be similar to the zinc-lead deposits of the Irish Midland Orefield, and other similar deposits worldwide, where the lower most massive limestone horizon tends to be the most strongly mineralised".

Should that statement be taken as only applying to the idea that the lowest limestones may be better mineralised than those higher up the succession and not to any other aspects of the mineralisation such as age, tectonic setting etc?

Dave Greenwood

Dave

Pallas Green is hosted at or near the base of the Waulsortian sequence of late Courceyan age in that part of Ireland (can be more precise but dont really want to introduce conodont biostratigraphy into this post !!!). The mineralization is definitely no older than early Arundian from palaeomagnetic dating.

The only Waulsortian I know about in the NPO is around Ashness Knoll in Clitheroe and, maybe, in the Stainmore Trough.

The old "first clean limestone" theory does not work in Ireland but probably does in the NPO and is really only relevant to Mississippi Valley Type (MVT) mineralization and not to Irish-type. Hence I am sure that Peter and Terence used it in the sense of being the potential host for epigenetic mineralization and not suggesting the potential for Irish-type (sensu stricto) mineralization.

Just for the record I coined the term Irish-type in a paper in 1978 and have written more than 40 published papers on Irish-type Zn-Pb deposits not ony in Ireland but also in Thailand and Tasmania.

Best

:offtopic: but...

Could someone point me towards something that would simply explain, I am a mechanical engineer after all, what some of these wonderfully sounding words mean before I go off and give them some spurious and possibly amusing (after a few pints) meaning?
Such as:
epigenetic
sensu stricto
conodont
coeval

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epigenetic - formed after diagenesis of the host rocks, i.e in a process separate from the formation of the host rocks

sensu stricto - opposite of sensu lato, meaning in the strict sense

conodont - fossilized worms teeth. Commonly found in sedimentary rocks and used to determine the biozonal age of rocks as they evolved very rapidly.

coeval - at the same time

So anyway - does anyone reckon this company could be a good bet for buying shares? I've heard the price of zinc is likely to rocket by 2014! 😉

Id expect to hear results for holes 4-6 pretty soon. At the time of the last rns the fourth hole results were being analaysed, I presume the 5th holes was in the process of being drilled and with no obvious delays regarding the weather id imagine hole 6 is completed or very close to being finished.