This might explain why I did'nt really notice anything here except a blocked level. I was down in October 2015.

Thanks for clarifying this, as I thought I'd overlooked a bit. Also explains why no one else with me found it either. And no, we won't do any poking so to speak. A bit wary of slate falls to be honest. They have a nasty habit of moving ;(

Just out of interest, what's beyond the other fall east of Z4 with the blocks? Much the same I believe. Can you actually see up into any part of Z3 beyond this fall by any chance?

Well, Z4 is open as you know, Z3 is collapsed quite badly, but it's in line with the fault so it's to be expected.

Speedy and Llion pushed Z3 quite hard about 8 years ago. Progress up to higher in the chamber proved impossible (and if they say it was impossible, then it must have been as both are raving lunatics).

They did manage to get in the level that leads to Z2 (floor 3) but Z2 was also collapsed and it didn't look possible to even attempt it. At least that's what got reported back to me, I remained in Z4 like a coward ;)

We looked at Z3 again last week and failed to get through to Z2 despite being rather pushy with it. I think it's consolidated in the 8 years and closed up.

I think to get through Z3 and Z2 now would be a fairly major mining operation...

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Miles, many thanks for the further clarification. Will leave well alone. but hope to be back for a further potter about the still accessible lost world, if only to admire those lovely blocks of Welsh slate 🙂

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Miles, many thanks for the further clarification. Will leave well alone. but hope to be back for a further potter about the still accessible lost world, if only to admire those lovely blocks of Welsh slate :)

They are very lovely. Back vein, so slab, not much good for roofing slates.

It's not impossible that one day progress will be made inbye but if it ever happens it'll be a major operation with time, money, people and equipment that's sadly not on the table at present.

Got my eye on some other projects which are a little more viable, that'll hopefully open up a bit of interesting ground...

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I've been thinking about the drop fault. First thing to say is that both the chamber 38 and chamber 32 cross-sections made by Thomas Jones & his son Percy show the fault line at an angle of 65 degrees to the horizontal when measured parallel to the pillaring line i.e nominally parallel to the chamber walls. Now whether it runs in a straight line on floor F from chamber 32 to chamber 25 is a good question. It seems a possible starting point - but given that we are working in three dimensions and that there are other "slips" or "pefels" in this volume of the workings in various directions and inclinations, this may be over simplistic. Quite why the actual line of the fault was not marked clearly on the surveys is a bit of a puzzle.
I think a part of the answere as to why there are three sections of the Back vein on floor 3 is down to hards much rather than the fault. I have drawn a scale "ladder" of the floors on a 65 degree slant and am going to attempt some cross sections of my own based on it and the surveys. This may give a clue. I think additional data regarding the hards/layers may come from the N.W.S.Co. final plan which identifies them on many floors in Cwmorthin and therefore should be able to transpose (?) them into oakeley. Will let you know.
As I said earlier, I do need to combine some elements of New, Old and Back vein plans (sighs!)

Grahami

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Interesting!

Graham, by "hards" do you mean whinstone dykes or the presence of other similar igneous intrusions which could result in the workings being broken up in a complex manner?

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Thanks for the info :)

Just got in after spending all evening swinging around on the old chains in Z6. Had my life entirely in the hands of the old pegs at numerous points, they are all still good.

Found a nice set of carved initials up at the top of the face.

Chris and I pushed up Cwm's chamber 17 BV on lake level to see if it roofed into Z4. We got quite high up 17 but couldn't see it going through the roof, though it might have done, we could only see very small areas of it as it's full of fall and we had to worm our way between the blocks.

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More thoughts:
The two cross sections (32 and 38) do not depict the Back vein well - 32 was prepared in 1923, 38 originally in 1917, and while the map accompanying the 38 cross section was certainly updated with the work after the dewatering, I do not think the same can be said of the cross section.
I therefore think the arrangement of whinstone dykes, hards etc., in the Back vein can not be relied on.
As a first approximation using the angle of the fault, and marking the floor heights, I think I can confirm that the most southerly of the Floor 3 "lost world" levels and whose chambers connect with the lake level is immediately to the south of the fault line - and the fault probably forms the north wall of the level. The other two levels - central and northern do not appear to correspond to anything yet - insufficient data.
I wonder if the next explorers in the area could try and ascertain the angle of the layers forming the roofs of the chambers - it would give us a handle on the nature of the roof i.e. if the angle matches the dip of the vein, then it may well be a chert or similar, if steeper, then probably a whinstone dyke.
I will try to use the layers marked on the main Lower Quarry plans for the DE and G back vein levels and see if that helps.

Grahami

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Thanks again for the excellent info - consider it taken on board.

I will measure the angles next time I'm there. From memory, the larger southern galley of chambers has the roof at the normal bedding angle.

The mid galley is impossible to say at the present time as we can only see one chamber and the proper roof is on the floor, the space above having arched over. The next chamber has yet to be entered but it's also full of fall (the rocks being very clean and wet, due presumably to the water coming down vertically).

The northern galley roofs seem a bit steeper I think, possibly closer to the cleavage angle. These chambers, to me, just have a very similar look and feel to the isolated North vein workings up on the Fl5 tip. But that's possibly just me talking rubbish.

These workings all date from Robert Roberts time right?

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Miles,

In relation to the possibility that the level at the top of Z4 breaks into 17 BV of Cwm, have you seen on this plan

http://www.aditnow.co.uk/documents//1900-2.pdf 

just below the writing 'WALL Z4' (in red ink) is written (rather faintly) 'Robert Roberts Connection 1900'.

As there is nothing shown on this plan of Z6 where our present connection up to Lake Level occurs, this perhaps suggests that a Z4/17BV connection could have been made at this time.

Miles,


just below the writing 'WALL Z4' (in red ink) is written (rather faintly) 'Robert Roberts Connection 1900'.

.

Although this sounds exciting, I'm sorry to say I
think this pencilled annotation refers to the Oakeley old vein floor 1 / Cwm old vein floor C connection, which is well known.


Must admit not that easy to see these added pencil marks

While on the subject of holes through the roof of chambers, I seem to remember there is a hole in the roof of Cwm chamber 8 E old vein. Wonder what this actually is, assuming its not been naturally formed by rock falling away

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