Exploring the Geology of Marsland Mouth, North Devon

devongeography

Aug 28

Marsland beach. Image - Google Earth

Marsland Mouth is found in an extremely remote location, but your efforts to get there will be well rewarded. There are two short walking routes possible. Firstly, you can follow the South West Coast Path from the car park at Welcombe Mouth (see map). This walk is only around 750 metres in length, but involves a very steep climb out of Welcombe, and then a steep descent to Marsland.

To drive to Welcombe Mouth, take the the A39 Bideford to Bude (Atlantic Highway) road past the Westcountry Inn and on to Welcombe Cross. Here, you can turn right to the village of Welcombe, and follow narrow lanes to the car park at Welcombe Mouth at map reference SS213 179 (post code for Sat Nav: EX39 6HL). However, be warned! The last section of road to the car park is unsurfaced, and riddled with loads of deep and large pot holes.

Location of Marsland Mouth N D Map

Alternatively, you can navigate your way to the delightful 'Old Smithy' public house at Darracott (SS231 179). I stayed overnight here in my camper van, and from here it is a mile and a half walk along a quiet country road to Marsland Mouth, with a very steep descent to the coast. Don't forget to factor in as steep climb and another mile and a half to walk back!

Location of Marsland Mouth

Location of Marsland Mouth PDF Map: Location of Marsland Mouth

To get to Marsland Mouth from the Old Smithy Inn, leave the pub entrance, and turn right to follow road. After passing an old public telephone box, the road takes you past a large dairy unit at Leddon Farm, Berry Park and Welcombe House, before reaching the Mead Corner road junction. Continue straight on here, following the sign to Morwenstow - unsuitable for vehicles.

The surfaced road continues for a short distance, passing on the right an entrance to Blueberry Hill. At a gate that marks the end of the road, ignore the bridleway that leads off to the left, and carry straight on descending steeply on an unsurfaced lane towards the coast.

The lane follows the north side of the Marsland Water valley, and provides access to the buildings of West Mill below, once the home of the white witch, Lucy Passmore, and now privately owned. Above the mill, it is possible to pick out the old mill pond and line of the old leat that once channelled water from the stream, creating sufficient energy to drive a waterwheel.

"In only one of these 'mouths' is a landing for boats, made possible by a long sea-wall of rock, which protects it from the rollers of the Atlantic, and that mouth is Marsland, the abode of the White Witch, Lucy Passmore." (Charles Kingsley – 'Westward Ho!')

Approaching West Mill. Image - Paul Berry

Follow the permissive path that detours around West Mill and takes you to a bench on a flat plateau at the cliff edge, offering great views of the beach below. Take care though, as there is a very steep drop here, and no fencing to offer protection. From here, the path follows the course of the stream of Marsland Water, and eventually reaches a footbridge.

Footbridge at the county boundary of Devon and Cornwall. Image - Paul Berry

The stream here marks a county boundary, and by crossing the bridge, you walk from Devon into Cornwall. The boundary between the two counties wiggles along the contours of the land for around 65 miles from the Atlantic coast to the English Channel to the south. The border is marked by the course of the river Tamar for 60 of these miles as it flows southwards, and just a mile away from its source, the much smaller Marsland Water rises and flows in the opposite direction (to the north coast) to mark the remainder of the boundary that changes all rules regarding how cream teas should be served – jam first in Cornwall, but not in Devon.

Lower valley of Marsland Water with Gull Rock in the distance. Image - Paul Berry

The path winds its way down to the beach. Take a look back up the valley from here, to see how deeply the stream has incised into its valley, eating into in the thick deposits of 'head' material that infilled the valley here due to solifluction in the peri-glacial conditions that existed at the end of the last (Devensian) glaciation, some 18,000 years ago. The last section of the stream is so deeply incised, it has created a small gorge. In later times and in warmer climes, a sequence of flat terraces were cut into this deep head material. The mixed porridge of head material is more easily visible in the cliffs at the south end of the valley, and also on the slopes between West Mill and the valley side.

Steep sided lower valley of Marsland Water. Image - Paul Berry

Head material exposed by erosion from Marsland Water. Image - Paul Berry

Mouth of Marsland Water. Image - Paul Berry

If you look to the top of the cliffs away to the north (to the left as you face inland), you can pick out a small stone writer's hut perched precariously close to the edge. If you walked here from Welcombe Mouth, you would have passed this on the coast path. It was used by poet and playright Ronald Duncan, who sought inspiration here. Duncan had his home at Mead Farm, just a mile or so inland, and died in 1982.

Ronald Duncan's writing hut. Image - Paul Berry

Work your way down to the beach itself to study cliffs of the sandstone and mudstone rocks of the Upper Carboniferous period, known as the Crackington Beds (318-328 million years). There are some superb examples of sharp folding exposed here – evidence of geological events that took place around 300 million years ago in the Variscan Orogeny.

Geological Column Diagram - Peter Keene

The Variscan Orogeny was a period of mountain building that took place in the late Carboniferous/early Permian periods and lasted for around 100 million years. At this time (when the Atlantic Ocean did not exist), plate movements resulted in the northern land mass of Laurasia (containing Europe and North America) colliding with the southern continent of Gondwanaland (containing South America, Africa, Antarctica, Australia, and India). This closed the Rheic Ocean that was located between the two giant land masses, and created a new supercontinent called Pangea.

Diagram - Peter Keene

In the Carboniferous period (290-350 million years ago, and before the plate collision), rivers from South Wales brought sediments into a basin containing a shallow, brackish sea – fine sediments leading to mudstone rocks, and coarser sediments leading to sandstones. As sediments were being laid down in this basin, mountain building was taking place to the south. The later squeezing of the two plates compressed the basin, buckling these layers and raising them high above sea level in the final stages of the Varsican. The exposed cliffs of Marsland Mouth are the remaining stumps of these folded rock beds.

Marsland beach. Image - Paul Berry

Cliffs and storm beach, Marsland. Image - Paul Berry

Looking out to sea, you can identify the headland of Gull Rock to the south (left hand side as you look), and possibly pick out the arch known as Devil's Hole.

Marsland beach with Gull Rock in the distance. Image - Paul Berry

Retrace your steps to the county boundary footbridge. From here, you can return to Welcombe along the coast path, continue back the way you came, or if you want to take a different return route, cross the bridge and follow the path on the south side of the valley. This takes you into the Devon Wildlife Trust's Marsland Mouth Wildlife Reserve, which covers 523 acres and is part of the Marsland to Clovelly Coast SSSI. The land was donated by keen conservationist Christopher Cadbury of the famous chocolate family, following his death in 1991. The path leads through an oak woodland before crossing Marsland Water, and eventually meets up with the original route at the gate you passed through before descending down the steep lane towards West Mill. From here, retrace your route along the road to the Old Smithy.