Wednesday 27 April 2016

Blaen Pig iron spring

Johnny and I went hunting for fossils today (as you do... he's only in Kindergarten four days a week, and Clare was working in Devon so I took the day off).  I wanted to try somewhere in VC35, so I could keep an eye out for bryophytes, and as my home patch is fossil-free Old Red Sandstone I headed west towards the Coal Measures at Blaen Pig (N of Gilwern Hill).  This is a vast area of spoil, some of which is very old whilst other areas are much more recent.  I have searched it 5 times over the last 16 years, but there are still many bits that haven't been checked bryologically.


I have seen small, dense Dichodontium on the coal tips a few times before, as well as on ledges on upland limestone in Carms & Brecs, and I think that Charles has reported similar plants from NPT.  It seems to match the old "var. fagimontanum", and looks much more distinctive than the ever-intergrading pellucidum and flavescens.  There were several patches on damp, slightly basic coal spoil near the foot of the tips.


After a while we came across a spring, where extremely iron-rich water bubbles out from below a tip (but perhaps associated with a natural break of slope).  This held Potamogeton polygonifolius, Eriophorum angustifolium and other common flush species (but no Pinguicula that I could see), plus Campylium stellatum var stellatum new for the tetrad (the mega-rich SO21K) and several common sphagna.  For a while, the highlight was potential Sphagnum teres, but I have reluctantly concluded it's just one of the peculiar brownish, scarcely squarrose forms of Sphagnum squarrosum that one occasionally encounters.

Johnny enjoyed the iron spring, and also a few small fern fossils

2 comments:

  1. Sam, good to see you had someone with you who was able to show you how to do this bryology thing properly...

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  2. Yes Sam, it looks similar to some of the dense swords of Dichodontium that populate the damp grit at the sides of forestry tracks in NPT.

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