TR: Western Brecons 3-day backpack

GeoffC said:

The Western Brecons 3-day backpack report, photos and 1
partial pan uploaded.

v-g.me.ukTrips%20Photos%20List.htmOpen ↗

Enjoyed your report and pics. Interesting route you took,
I'd have done the last part a bit differently. I'd have
turned due west and gone over Disgwylfa, Carreg Lem and
Llorfa to Tyle Garw, then followed the Afon Twrch southwards
on the east bank.

A few points about your route description. You mention the
"small rise of Bannau Sir Gaer". Actually that little bump
is Waun Lefrith. The name Bannau Sir Gaer means
"Carmarthenshire Beacons" and refers to the whole ridge,
including the main peak Picws Du, which is usually called
Bannau Sir Gaer. Bannau Sir Gaer is the mountain
(escarpment) name, Picws Du is the summit name.

As for your "horrendous" return route on the west side of
the Afon Twrch, you'd have done better to climb up to Cefn
Carn Fadog to avoid that bit, but staying on the east side
would have been even better, following the ridge above Tyle
Garw. There are easier paths on the east side.

As for your photos, the fourth shot which you've labelled
Fan Brycheiniog is actually Fan Foel, that's the end of the
ridge that extends north from Fan Brycheiniog. The last two
shots could be labelled Tyle Garw, because that's the steep
slope shown in the photos. Great hillside that, climbed up
and down it a few times, terrific area for bilberries when
they're in season.

You mention the limestone slabs on the west side of Garreg
Las. Are you sure about this? I thought they were millstone
grit. Unfortunately I've lost my geological maps of the area
and a web search failed to throw up anything. If anyone can
point me to a decent geological map of Mynydd Du I'd
appreciate it.

South-west of the main old red sandstone peaks the geology
is a complex mixture of limestone and millstone grit. Much
of the lower land is limestone, hence all the sink holes,
caves and stuff while many of the summits in the area are
capped with millstone grit, for example Carreg Goch, Tyle
Garw, Cefn Carn Fadog. The millstone is grey and slabby and
often has deep cracks in it, whereas the limestone tends to
erode into more curvy shapely patterns. Some of the summits
are limestone, for example Cribarth, Twynwalter, Carreg yr
Ogof and Foel Fraith. The limestone summits tend to be
pitted with sink holes while the millstone summits aren't,
even though the sink holes sometimes get quite close to the
summits (as on Carreg Goch).

I wish I could find my geological map.

Paul
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On Sun, 23 May 2004 13:31:09 +0100, "Paul Saunders"
<[email hidden]> wrote:

Hi Paul, I had a feeling you might reply to this one!.

Quoted message said:

Enjoyed your report and pics. Interesting route you took,
I'd have done the last part a bit differently. I'd have
turned due west and gone over Disgwylfa, Carreg Lem and
Llorfa to Tyle Garw, then followed the Afon Twrch
southwards on the east bank.

Yes, that Disgwylfa route looks good and we have already
noted it for a future trip.

Quoted message said:

A few points about your route description. You mention the
"small rise of Bannau Sir Gaer". Actually that little bump
is Waun Lefrith. The name Bannau Sir Gaer means
"Carmarthenshire Beacons" and refers to the whole ridge,
including the main peak Picws Du, which is usually called
Bannau Sir Gaer. Bannau Sir Gaer is the mountain
(escarpment) name, Picws Du is the summit name.

This always did confuse me a bit, the map has the legend
'Bannau Sir Gaer' on both the end peak and along the
escarpment. I've seen this name and Waun Lefrith applied to
the peak but I can't remember where, but on reflection I
agree. I shall defer to your local expertise and change it
to Waun Lefrith, to remove ambiguity.

Quoted message said:

As for your "horrendous" return route on the west side of
the Afon Twrch, you'd have done better to climb up to Cefn
Carn Fadog to avoid that bit, but staying on the east side
would have been even better, following the ridge above Tyle
Garw. There are easier paths on the east side.

Tell me about it!. When we reached the end of the high
ground near the chimney, we could see a fairly clear line
coming straight down from Cefn Carn Fadog. We noted at the
time, amidst the dubious language, that we would climb
straight up and descend along the ridge next time as it
couldn't be any worse than that awful bridleway. We'll keep
in mind the east side too.

Quoted message said:

As for your photos, the fourth shot which you've labelled
Fan Brycheiniog is actually Fan Foel, that's the end of the
ridge that extends north from Fan Brycheiniog. The last two
shots could be labelled Tyle Garw, because that's the steep
slope shown in the photos. Great hillside that, climbed up
and down it a few times, terrific area for bilberries when
they're in season.

There are so many names on maps for bits of hills, in
addition to the summit peak and the entire hill, that
on many occasions we give up the idea of a definitive
name for what we are describing and just hope it's
clear from the map!.

Quoted message said:

You mention the limestone slabs on the west side of Garreg
Las. Are you sure about this? I thought they were millstone
grit. Unfortunately I've lost my geological maps of the
area and a web search failed to throw up anything. If
anyone can point me to a decent geological map of Mynydd Du
I'd appreciate it.

Well we are not geologists, but walking up the spine of
Garreg Las, if that wasn't limestone pavement it was the
best imitation we've ever seen. We were stepping over
fissures and grikes just like in the Yorkshire Dales and it
certainly looked like limestone. We have read a description
somewhere that referred to it as limestone but again we
can't remember where - maybe one of the walking magazines
years ago .It would be interesting if anyone could confirm
this one way or the other.

Best regards

-- GeoffC

"GeoffC" <[email hidden]> wrote

Quoted message said:

Quoted message said:

You mention the limestone slabs on the west side of
Garreg Las. Are you sure about this? I thought they were
millstone grit. Unfortunately I've lost my geological
maps of the area and a web search failed to throw up
anything. If anyone can point me to a decent geological
map of Mynydd Du I'd appreciate it.

Well we are not geologists, but walking up the spine of
Garreg Las, if that wasn't limestone pavement it was the
best imitation we've ever seen. We were stepping over
fissures and grikes just like in the Yorkshire Dales and
it certainly looked like limestone. We have read a
description somewhere that referred to it as limestone but
again we can't remember where - maybe one of the walking
magazines years ago .It would be interesting if anyone
could confirm this one way or the other.

I've never studied geology but I think if you really wanted
to know you could get a sample and bung it in a bit of acid.
Vinegar will make limestone fizz or as I've just tested even
orange squash will to some extent if you take an optimistic
view of the definition of the word fizz. Limestone is mostly
calcium carbonate. Millstone grit, I believe, is a type of
sandstone and sandstone doesn't fizz in acid because it's
mostly silicon dioxide.

"AndyP" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

"GeoffC" <[email hidden]> wrote

Quoted message said:

Quoted message said:

You mention the limestone slabs on the west side of
Garreg Las. Are

you

Quoted message said:

Quoted message said:

Quoted message said:

sure about this? I thought they were millstone grit.
Unfortunately I've lost my geological maps of the area
and a web search failed to throw up anything. If anyone
can point me to a decent geological map

of

Quoted message said:

Quoted message said:

Quoted message said:

Mynydd Du I'd appreciate it.

Well we are not geologists, but walking up the spine of
Garreg Las, if that wasn't limestone pavement it was the
best imitation we've ever seen. We were stepping over
fissures and grikes just like in the Yorkshire Dales and
it certainly looked like limestone. We have read a
description somewhere that referred to it as limestone
but again we can't remember where - maybe one of the
walking magazines years ago .It would be interesting if
anyone could confirm this one way or the other.

I've never studied geology but I think if you really
wanted to know you could get a sample and bung it in a bit
of acid. Vinegar will make limestone fizz or as I've just
tested even orange squash will to some

extent

Quoted message said:

if you take an optimistic view of the definition of the
word fizz. Limestone is mostly calcium carbonate.
Millstone grit, I believe, is a

type

Quoted message said:

of sandstone and sandstone doesn't fizz in acid because
it's mostly

silicon

Quoted message said:

dioxide.

Due to a knee injury I was unable to take a walk this
weekend but we did take our youngest upto Dan-yr-ogof
caves...wished I has listned and observed a little more
because I am sure the *Morgan* bros gave a full description
of rocks n stuff in the area !

Drove up the valley towards Sennybridge then took a right
just before and ended up for a cuppa at the Brecon Beacons
visitor centre. Wasn't on the moutains but was able to drive
around today and have a look at them which was nice.

I plan on doing some walks of the Carmarthen Fans shortly,
can someone recommend some circilar routes of about 5 hours
taking in some peaks?

thanks in advance

AndyP wrote on Sun, 23 May 2004 17:39:37 +0100....

[testing for limestone]

Quoted message said:

I've never studied geology but I think if you really
wanted to know you could get a sample and bung it in a bit
of acid. Vinegar will make limestone fizz or as I've just
tested even orange squash will to some extent if you take
an optimistic view of the definition of the word fizz

Of if you forgot to pack any vinegar or orange juice, just
rub two bits of stone together and then sniff them. Quite a
distinctive smell.

--
Tim Jackson [email hidden] (Change
'.invalid' to '.co.uk' to reply direct) Absurd patents:
visit patent.freeserve.co.ukpatent.freeserve.co.ukOpen ↗

GeoffC said:

Yes, that Disgwylfa route looks good and we have already
noted it for a future trip.

Not that much ascent and descent, the valleys are
quite shallow between those ridges, until you get to
the Afon Twrch.

Quoted message said:

This always did confuse me a bit, the map has the legend
'Bannau Sir Gaer' on both the end peak and along the
escarpment. I've seen this name and Waun Lefrith applied
to the peak but I can't remember where, but on reflection
I agree. I shall defer to your local expertise and change
it to Waun Lefrith, to remove ambiguity.

It's for the best. Nuttall list it as Waun Lefrith and most
summit lists refer to the main Peak as Bannau Sir Gaer,
that's what I always call it, but I suppose I'm thinking of
the whole ridge.

Just to clarify, Bannau Sir Gaer means Carmarthenshire
Beacons and refers to the following summits - Picws Du, Cwar-du-
mawr, Cwar-du-mawr and Waun Lefrith, two of them with
negligible ascent.

Fan Brycheiniog used to be correctly called "Bannau
Brycheiniog" on older maps and also referred to multiple
summits on a ridge - Fan Brycheiniog (as we now call it),
Twr y Fan foel and Fan Foel, again two of them with
negligible ascents.

The name Bannau Brycheiniog was changed some years ago to
Fan Brycheiniog for some reason, indicating a single summit,
namely the highest one (the one with the trig and shelter)
except that it isn't the highest. Twr y Fan Foel is exactly
the same height. So the original name Bannau Brycheiniog is
arguably more accurate since it indicates multiple summits.
I consider that one to rank as a "double summit".

Quoted message said:

Tell me about it!. When we reached the end of the high
ground near the chimney, we could see a fairly clear line
coming straight down from Cefn Carn Fadog. We noted at the
time, amidst the dubious language, that we would climb
straight up and descend along the ridge next time as it
couldn't be any worse than that awful bridleway. We'll
keep in mind the east side too.

The west side of Cefn Carn Fadog has an easy path running
around it, it's an old tramway that leads right to the large
chimney. Alternatively you could have dropped down to the
Afon Twrch at Nant y Llyn, crossed the river (easy if there
isn't too much water in it) and followed the valley south.
That's a terrific valley, one of my favourites. At the
southern end of Tyle Garw the path contours up and around to
the waterfall at Llywncwmstabl then leads to Dorwen and Pen-y-
wern, then back down into the valley at the footbridge.
Dorwen is (or was last time I was there) abandoned and Pen y
wern might be too, and Cyllie farm is just a ruin too.

The east side, along the top of Tyle Garw is the best route
in the area IMO, along that er, limestone pavement/millstone
grit stuff...

Quoted message said:

Well we are not geologists, but walking up the spine of
Garreg Las, if that wasn't limestone pavement it was the
best imitation we've ever seen. We were stepping over
fissures and grikes just like in the Yorkshire Dales and
it certainly looked like limestone.

Maybe it is, I'm not sure, but if it is it's a different
kind of limestone to others in the area and there are no
shake holes along the ridge. Harveys map shows many of those
summits as having limestone pavement but I had a very good
geological map years ago which I'm convinced showed the same
summits as being topped with millstone grit.

Note that the millstone grit in this area is nothing like
the grit in the Peak District. This grit is grey and hard
and smooth. Most of the waterfalls in the Ystradfellte area
cross millstone grit and there's an actual millstone on
display outside an old mill in the one of the valleys which
confirms the nature of the local grit. Further north the
valleys turn to limestone and suddenly we find the river
frequently disappearing underground with lots of caves and
potholes about. The rock in these rivers is quite different,
diplaying the curved shapes typical of eroded limestone (Cwm
Pwll y Rhyd is an excellent example), unlike the rectangular
blocky nature of the millstone grit.

Yet Bill Grey told me that a guide to the area said that
Sgwd Gwladus is a limestone fall. If so it must be a
different kind of limestone, a much harder type, since it's
obviously eroded differently and more to the point, the
river just disappear underground at low water as in other
limestone areas.

So maybe there's more than one kind of limestone summit in
the area - a soft, curvy, spiky type surrounded by shake
holes, and a harder, slabby type that splits and cracks but
doesn't erode the same way, doesn't have sink holes around
and doesn't seem to be permeable like the softer type.

Judging by the geological maps I used to have my money is on
the latter being millstone grit (the local hard grey stuff)
and people being confused about which is which. One thing
that was apparent from the maps is the extremely complex
nature of the geology in the area, the limestone and
millstone are extremely mixed up, so both types often occur
in close proximity, adding to the confusion. If they are
both limestone then they are quite different in nature. Just
look at the change in the character of the ground (as well
as the rocks) when you cross from Carreg yr Ogof to Garreg
Las or Carreg Goch to Twynwalter for instance.

Quoted message said:

It would be interesting if anyone could confirm this one
way or the other.

Yes, I really must get my hand on another good geological
map and check it out with GPS precision. In the meantime, is
vinegar the best test? Must remember to take some with me.

Paul
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AC said:

I plan on doing some walks of the Carmarthen Fans shortly,
can someone recommend some circilar routes of about 5
hours taking in some peaks?

I could, but you'd probably want to walk much further
than that. ;-)

What sort of distance would you like to do?

Paul
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"Paul Saunders" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

AC said:

I plan on doing some walks of the Carmarthen Fans
shortly, can someone recommend some circilar routes of
about 5 hours taking in some peaks?

I could, but you'd probably want to walk much further than
that. ;-)

What sort of distance would you like to do?

Not sure of distance or where best to start from but would
like to take in the main ridges - I don't walk fast and
stop a lot to take in the views (in my top 3 reasons for
walking the mountains) I would say though a relatively easy
path to follow.

If I had to guess at a distance I would say between 7
to 8 miles?

My mate I walk with tends to moan if I talk *up* distances
coz at 10 years my elder he thinks he is not capable - but
he is probably fitter than I in reality!

In article <[email hidden]>, Paul
Saunders <[email hidden]> writes

Quoted message said:

By the way, I incorrectly quoted Bill Grey as saying that
Sgwd Gwladus was limestone. As he pointed out to me last
night it's sandstone, not limestone, known as the "12 foot
sandstone".

Being a modest type, I have to admit that I read the
information out over the phone to Paul from a pamphlet
produced by the Geologists' Association ( South Wales Group)
obtained at the Information Centre at Pont Neath Vaughan.
--
Bill Grey billboy.co.ukbillboy.co.ukOpen ↗

In article <[email hidden]>, Ferlas Mor
<[email hidden]> writes

Quoted message said:

Bill and Paul, try to get your hands on a copy of
F.J.North's "The River Scenery at the Head of the Vale of
Neath" published by the National Museum of Wales.

While on the subject of geology of the Beacons, I have a
book here called:

"The Brecon Beacons National Park" by Roger Thomas.

It is a Countryside commission OFFICIAL GUIDE.

On page 18 it shows a lovely photo of Llyn-y-Fan Fach with
Picws Du and fan Foel

Beneath is the caption,

"Llyn Cwm Llwch - a text book example of a glacial lake
produced by the north facing scarp in the central beacons"

Oooops - so much for officialdom!
--
Bill Grey billboy.co.ukbillboy.co.ukOpen ↗

GeoffC said:

Well we are not geologists, but walking up the spine of
Garreg Las, if that wasn't limestone pavement it was the
best imitation we've ever seen.

Well I have bad news for you, it isn't. As I originally
thought it's millstone grit.

Quoted message said:

We were stepping over fissures and grikes just like in the
Yorkshire Dales and it certainly looked like limestone.

Well it's grey and it cracks and splits a lot but that's
what the Beacons millstone is like. Doesn't the Yorkshire
Dales have millstone grit too? Perhaps when they occur in
close proximity people confuse the two. I've seen plenty of
photos of the limestone pavement up there and it definitely
doesn't look the same as the exposed rocks on Garreg Las.
The top of the pavement is weathered differently. Limestone
pavement weathers in a very complex way due to the acidic
reaction wtih rain, but the millstone remains pretty smooth.

Quoted message said:

We have read a description somewhere that referred to it
as limestone but again we can't remember where - maybe one
of the walking magazines years ago

I've also read that Garreg Lwyd is limestone but that isn't
either, only the northern edge of it. Perhaps people see the
limestone quarries on the northern edge and assume the whole
summit is made of the same stuff. If they write about it the
misinformation spreads.

Quoted message said:

.It would be interesting if anyone could confirm this one
way or the other.

Well I couldn't get hold of a detailed geological map of the
area but I did manage to find a geological map of Wales. Not
as detailed as a larger scale map obviously but it gives a
good overview. I scanned part of it and overlaid a black and
white 50k scale map over it, the Mynydd Du part of it can be
seen here; wildwales.fsnet.co.ukmdg.jpgOpen ↗

The browns indicate old red sandstone, the blues limestone,
the greenish greys millstone grit and the neutral greys in
the southwest (may look slightly pink in comparison) are the
coal measures. The thick black lines are faults.

Dotted areas indicate sandstone type rock, brick areas
limestone and non-dotted areas indicate mostly mudstone and
siltstone. Thus there are two types of millstone grit, a
sandstone type and a mudstone type. The map also
differentiates five different types of limestone, four shown
as blue bricks, the other shown as a smooth darker blue.

Note that most of the southern summits in Mynydd Du are
millstone grit and that the limestone mainly forms the low
ground between the southern and northern summits, since the
millstone is harder than the limestone in this area (the
reverse it true in Gower). The only true limestone summits
are Carreg yr Ogof, Cribarth and Tywnwalter (east of
Disgwylfa, not named on this map), while Foel Fraith is a
partial limestone summit.

Note also how closely the north facing crags of Llorfa,
Disgwylfa, Carreg Goch and Castell y Geifr match the border
of the millstone and the limestone. Perhaps some of those
crags are limestone or perhaps they just drop to the
limestone below. I'd need to get a more detailed map to see
precisely where the border lies. There's an interesting
mixture of millstone grit crags and shake holes in this
border area.

To the south of Garreg Las is Tyle Garw, which displays
exactly the same type of "fissures and grikes" that you
describe on Garreg Las, and that's well inside millstone
grit country. These same formations are also seen to the
southwest of Disgwylfa and Carreg Goch, and also further
east on Carreg Cadno and Carreg Lwyd (not shown on this map)
which are also millstone grit.

This confirms what my detailed geological map told me many
years ago, that most of these southern summits are millstone
grit, not limestone, but there seems to be a lot of
confusion about this. Harveys map of the Beacons incorrectly
depicts many areas of "limestone pavement" whereas in fact
it is simply "rock pavement", sometimes limestone, sometimes
millstone.

This is only a small part of a larger map. I've studied the
whole area and it matches my experience of the area very
closely. The limestone areas frequently contain quarries,
small and large, the millstone areas do not. As I said, the
character of the two rocks is quite different, the limestone
tends to erode in a curvy, complex, "sculpted" fashion,
often splitting up into sharp, axe head shaped rocks, with
shake holes in abundance, whilst the millstone tends to
crack and split to form large rectangular shaped blocks and
slabs (Tyle Garw is an excellent example of this).

An easily accessible example of the difference can be found
on the path leading up from the climbing club near Penwyllt
quarries up past Carreg Cadno. On the west side there is an
excellent example of limestone pavement which has been
fenced off so as to develop naturally, whilst to the east
the ground rises up to the slabby millstone grit of the
summit. This division is spot on on the map.

By the way, I incorrectly quoted Bill Grey as saying that
Sgwd Gwladus was limestone. As he pointed out to me last
night it's sandstone, not limestone, known as the "12 foot
sandstone".

Paul
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AndyP said:

I've never studied geology but I think if you really
wanted to know you could get a sample and bung it in a bit
of acid. Vinegar will make limestone fizz or as I've just
tested even orange squash will to some extent if you take
an optimistic view of the definition of the word fizz.
Limestone is mostly calcium carbonate.

I must remember to take some vinegar with me next time I
go up there.

Quoted message said:

Millstone grit, I believe, is a type of sandstone and
sandstone doesn't fizz in acid because it's mostly silicon
dioxide.

There are two types in the Beacons, one is a sandstone, the
other is a mudstone, much smoother.

Paul
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"Paul Saunders" <[email hidden]> wrote

Quoted message said:

Well I couldn't get hold of a detailed geological map of
the area but I did manage to find a geological map of
Wales. Not as detailed as a larger scale map obviously but
it gives a good overview. I scanned part of it and
overlaid a black and white 50k scale map over it, the
Mynydd Du part of it can be seen here;
wildwales.fsnet.co.ukmdg.jpgOpen ↗

I guess that answers my previous question except that I
wouldn't be likely to go over that way usually.

The message <[email hidden]>
from "Paul Saunders" <[email hidden]> contains these words:

Quoted message said:

climbing club near Penwyllt quarries

Careful Paul, that's the South Wales Caving club HQ and
cavers don't like being confused with us common types.

--
Roger Chapman so far this year 27 summits New - 16 (Marilyns
4, Sweats 1, Outlying Fells 11) Repeats - 11( Marilyns 2,
Sweats 6, Wainwrights 11) Knackered knee - 3 times

In [email hidden] Paul Saunders mused:
<snippety>

Quoted message said:

wildwales.fsnet.co.ukmdg.jpgOpen ↗

Cool!

--
A l'eau - c'est l'heure (French Navy Motto)

"Paul Saunders" <[email hidden]> wrote

Quoted message said:

Quoted message said:

Millstone grit, I believe, is a type of sandstone and
sandstone doesn't fizz in acid because it's mostly
silicon dioxide.

Quoted message said:

There are two types in the Beacons, one is a sandstone,
the other is a mudstone, much smoother.

Where would be a good place to pick up some millstone
grit from then? Somewhere around the waterfalls next time
we go? Small pieces a few cm across will do. I've been
building up a basic easily identified rock collection for
the kids at our school over the last couple of years as I
come across suitable samples on my walks. So far I've got
sandstone, shale and coal from the Forest of Dean, chalk
from Wiltshire, oolitic limestone from the Cotswolds,
carboniferous limestone from Cheddar Gorge, conglomerate
from Macgillycuddy's Reeks, mica schist and quartzite
from the Mamores, gneiss from somewhere around Ullapool,
slate from Snowdonia, granite from the Cairngorms and
I've got basalt and gabbro to get from Skye this summer
if we end up there.

The marble I got came from a broken table. Is there anywhere
on a good walk in this country to pick a bit of marble up
from? I remember a bit of research revealing a quarry or two
but I'm not going out of my way to get
it.

Roger said:

Quoted message said:

climbing club near Penwyllt quarries

Careful Paul, that's the South Wales Caving club HQ and
cavers don't like being confused with us common types.

Sorry, I meant caving club. Can't think why I typed
climbing...

Paul
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"W. D. Grey" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

In article <[email hidden]>, Paul
Saunders <[email hidden]> writes

Quoted message said:

By the way, I incorrectly quoted Bill Grey as saying that
Sgwd Gwladus was limestone. As he pointed out to me last
night it's sandstone, not limestone, known as the "12
foot sandstone".

Being a modest type, I have to admit that I read the
information out over the phone to Paul from a pamphlet
produced by the Geologists' Association ( South Wales
Group) obtained at the Information Centre at Pont Neath
Vaughan.

Bill and Paul, try to get your hands on a copy of
F.J.North's "The River Scenery at the Head of the Vale of
Neath" published by the National Museum of Wales.

It's the definitive volume on the development of the
waterfalls, caves and other limestone scenery in and above
the Nedd, Mellte and Hepste valleys. Though long out of
print (I think the last edition , the 4th, was published in
1962, I have a copy of the 3rd edition, 1949) secondhand
copies can still be picked up for a few pounds. It's not a
purely scientific tome and I'm sure it will add to your
appreciation and understanding of the area. Well worth
trying to pick one up.

--
Gwyn Reply to:- urw(dot)mail(dot)gwyn(at)xoxy(dot)net

AndyP said:

Where would be a good place to pick up some millstone grit
from then? Somewhere around the waterfalls next time we
go? Small pieces a few cm across will do.

I'd be wary of that approach if I were you. The geology is
quite complex around the waterfalls. More to the point,
hacking off a bit of grit is not easy, it's tough stuff.
Picking up some stones that happen to be lying around is
asking for trouble since all sort of stuff gets brought down
by the rivers. I was once very surprised to find some old
red sandstone in a stream high up above the falls. The
surprising bit was that there was no old red sandstone
upstream so either it had been laying there since before the
old red sandstone in that area had been eroded away, or it
was put there by aliens!

Anyway, I'm just saying to be wary of anything you pick up
near to a river, it could have come from anywhere.

I'd recommend getting some from one of the many millstone
grit summits in the area. Some are very easily accessible,
like Carreg Cadno for example.

Paul
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