is a science and In the first half of the book Paul describes the creation of the Paul Gannon technology writer. He is author landscape of South Wales. The second half of the book details South Wales of the Rock Trails series and sixteen walks, some easy, some more challenging, which bear South Wales other books including the widely evidence of the story told. A HILLWalker’s guide TO THE GEOLOGY & SCENERY praised account of the birth of the Walk #1 Pen y Fan The hills, valleys and coasts of South Wales are some of Britain’s most celebrated and electronic computer during the Walk #2 Sinc Giedd & Fan Hir iconic landscapes. The coasts of Gower and Pembroke, and the shapely peaks of the Second World War, Colossus: Bletchley Park’s Greatest Secret. Walk #3 Carreg Goch & Cribarth Brecon Beacons are especially popular. These varied landscapes reflect a highly diverse He also organises walks for hillwalkers interested in finding out Walk #4 Fan Brycheiniog & Bannau Sir Gaer geology. From the rolling hills of Mid and West Wales, the spectacular heights of the more about the geology and scenery of upland areas. Walk #5 Mynydd Llangynidr Brecon Beacons, the rocky outcrops of Fforest Fawr and Mynydd Du, the valleys and www.paulgannonbooks.co.uk Walk #6 Nedd Fechan & Mellte moors of ‘the coalfield’, to the delightful scenery of the southern and western coasts Walk #7 Pontneddfechan – each has its own fascinating geological story to tell. Press comments about this series: Walk #8 Rhondda Fawr This book is aimed at the walker who sets out among these hills and coasts and who Walk #9 Werfa wants to learn a bit more about the forces that forged this landscape. The first part “I was highly delighted to come across guide books written by Walk #10 Blaenavon is an account of the geological history of South Wales, while the second contains a fell walker covering classic UK mountain walks explaining Walk #11 Mumbles Head to Pwlldu sixteen walks where you can see evidence of the geology, along with some of the most the geology and landforms together with Walk #12 Worms Head to Port Eynon 1 outstanding scenery of the region. what can be seen and explored. Everything Pen y Fan Walk #13 Nash Point 1km is beautifully explained using simple but Fan y Bîg Craig 0 719m Cwmoergwm n y w T o r G l a s yn C wm Cribyn795m Craig C Start / Finish G w a u n P e r f e d d Minor road to colourful diagrams.” Walk #14 Cemaes Head TAF FECHAN Merthyr Tydfil NEUADD Pen 886my Fan RESERVOIRS Craig Cwm Sere G w a u n T a f n Ddu Graig Fa Corn873m Du Bwlch Craig Gwaun Taf Twyn Mwyalchod 642m Duwynt Deposits Magazine Craig y N Walk #15 St Davids Head Byllfa A N South T C R E W Walk #1 – Pen y Fan Walk #16 Mynydd Preseli A470 ISBN 978-1-906095-42-0 SO 0377 1696 Gannon Paul PLUS ••••• SO 0377 1696 N URS O ••••• 5 HO GATI START H NAVI ••••• FINIS TERRAIN TIME SEVERITY GRADE 125 ISBN 9781906095529 This route over Pen y Fan and Corn Du (and optionally Cribyn), as well as along an airy ridge from Craig Gwaun Taf to Graig Fan Ddu, is one of the most magnificent hill walks in South Wales, rivalled only by walks on the peaks of the Bannau Sir Gaer (CarmarthenPen y Fans)Fan, atsome 886m, 15km is the to thehighest west point(see Walks in Wales 2 and south 4). of Cadair Idris and the mountains of Snowdonia. Pen y Fan translates into English as the ‘head of the peaks’ and it sits, along with the slightly lower Corn Du, near the centre of a long scarp slope that runs for some 50km, from the Black Mountains in the east to Mynydd Du (also Wales known as the Black Mountain) in the west. Paul Gannon 9 781906 095529 A HILLWalker’s guide TO THE GEOLOGY & SCENERY ISBN 978-1-906095-24-6 ISBN 978-1-906095-38-3 ISBN 978-1-906095-15-4 A470 A470 Newtown Newtown Geology around South Wales Plynlimon Plynlimon A470 A470 752m Landscape around South Wales 752m A44 A44 0 10 20 Kilometres Aberystwyth A483 0 10 20 Aberystwyth A483 Miles Kilometres 0 12 Miles Llangurig 0 12 Llangurig Cardigan Cardigan A470 Bay A470 Bay Rhayader Rhayader New Quay A44 New Quay A44 A482 A482 Builth Wells Builth Wells Cemaes Head Cemaes Head Lampeter Lampeter Cardigan A483 Cardigan A483 A470 A438 A470 A438 Strumble Head Strumble Head A487 A487 Fishguard A485 Fishguard A485 A478 A478 Llandovery Llandovery A479 A479 A40 Brecon A40 Brecon St Davids A40 St Davids A40 Head Head A40 A40 Pen y Fan A40 Pen y Fan A40 Ramsey Island Carmarthen 886m Ramsey Island Carmarthen 886m A470 St Brides A470 St Brides A40 A48 Bay Haverfordwest A40 A48 Haverfordwest Abergavenny Bay Abergavenny A477 A477 Skomer Island A4076 A465 Skomer Island A4076 A465 Milford Haven Milford Haven Skokholm Island Skokholm Island Merthyr Tydfil Craig y Llyn Merthyr Tydfil Craig y Llyn 600m Carmarthen A465 600m Carmarthen A465 SM SN SN SO St Anne’s Head A4042 St Anne’s Head Tenby A4042 Tenby Pembroke Bay Pembroke Bay SR SS Caldey Island SS ST Caldey Island Swansea Swansea St Govan’s Head St Govan’s Head Newport Newport A470 M4 A470 Worms Head M4 Worms Head Mumbles Mumbles Head M4 Head M4 LIAS SILURIAN TRIAS ORDOVICIAN COAL MEASURES CAMBRIAN Cardiff Cardiff MILLSTONE GRIT PRE-CAMBRIAN OR SHROPSHIRE Lavernock Point Lavernock Point Nash Point CARBONIFEROUS LIMESTONE CONTEMPORANEOUS IGNEOUS ROCKS Nash Point OLD RED SANDSTONE INTRUSIVE IGNEOUS ROCKS South Wales Paul Gannon www.pesdapress.com Cover Photo: Mynydd Du looking east towards Fan Gyhirych Published 2016 Published in Great Britain by Pesda Press Tan y Coed Canol Ceunant Caernarfon Gwynedd LL55 4RN © Copyright 2016 Paul Gannon ISBN: 978-1-906095-52-9 The Author asserts the moral right to be identified as the author of this work. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the Publisher. Printed and bound in Poland, www.lfbookservices.co.uk To the colliers of South Wales Ripples in the Old Red Sandstone on Pen y Fan. Contents Introduction 10 CHAPTER 1 Under Wales 13 CHAPTER 2 Early Wales 19 CHAPTER 3 Old Red Wales 29 CHAPTER 4 Limestone & Grit 39 CHAPTER 5 Coal & Shale 55 CHAPTER 6 King Coal 69 CHAPTER 7 Post Carboniferous Wales 85 CHAPTER 8 The Ice Age in South Wales 91 CHAPTER 9 The Living Landscape 101 CONTENTS About the Walks ..................................... 123 Walk #1 Pen y Fan ............................................ 127 Walk #2 Sinc Giedd & Fan Hir ................................ 137 Walk #3 Carreg Goch & Cribarth.............................. 149 Walk #4 Fan Brycheiniog & Bannau Sir Gaer ............. 163 Walk #5 Mynydd Llangynidr ................................... 171 Walk #6 Nedd Fechan & Mellte ............................... 179 Walk #7 Pontneddfechan ...................................... 189 Walk #8 Rhondda Fawr ........................................ 197 Walk #9 Werfa .................................................. 205 Walk #10 Blaenavon ............................................. 213 Walk #11 Mumbles Head to Pwlldu ............................ 223 Walk #12 Worms Head to Port Eynon ......................... 237 Walk #13 Nash Point ............................................ 247 Walk #14 Cemaes Head .......................................... 253 Walk #15 St Davids Head ....................................... 259 Walk #16 Mynydd Preseli ....................................... 267 Glossary of Geological and Geomorphological Terms ............. 273 Books and Pamphlets Consulted in Writing This Book ............ 276 Acknowledgements ................................................... 278 Welsh Words ......................................................... 279 Geological Names in the Carboniferous Period in South Wales ... 281 Index of Place Names ................................................ 282 Sgwd Clun-gwyn waterfall, Afon Mellte. 9 Introduction The hills, valleys and coasts of South Wales are some of Britain’s most celebrated and iconic landscapes. The coasts of Gower and Pembroke, and the shapely peaks of the Brecon Beacons, are especially popular, attracting many hundreds of thousands of visitors. South Wales also offers other less well known yet immensely attractive landscapes. These varied landscapes reflect a highly diverse geology. From the rolling hills of Mid and West Wales, the spectacular heights of the Brecon Beacons, the rocky outcrops of Fforest Fawr and Mynydd Du, the valleys and moors of ‘the coalfield’, to the delightful scenery of the southern and western coasts – each has its own fascinating geological story to tell. This book is aimed at the walker who sets out among these hills and coasts and who wants to learn a bit more about the forces that forged this landscape. The development of the South Wales landscape is an amazing story involving the gargantuan forces generated by the collision of continental ‘tectonic plates’, as well as the slow, chemical breakdown of the rocks. This book gives the reader an appreciation of the relationship between geology and landscape. Whether it is detecting gross tectonic forces in folded rocks on the coast and inland, spotting ‘sink holes’ where surface water mysteriously drains underground, or identifying fissures that are precursors to landslides in the coalfield, this book will help the walker unravel the landscape they see around them. The book is divided into two parts: the first is an account of the geological history of South Wales, while the second part contains sixteen walks where you can see evidence of the geology, along with some of the most outstanding scenery of the region. Inevitably, in choosing just sixteen walks to represent the landscape of such a large area, I have had to make tough, arbitrary choices over which walks to include and which to leave out. However, it should be possible to apply what one can learn from the book, whether it be folds, sink holes or fissures, on walks elsewhere in the region.