SINS Day 1 – Saturday 27th May
Organisers: Lesley and Eric Brown (HOC)
Planner: Kerstin Mitchell (HOC)
Controller: Bob Brandon (OD)
Start Times: 12.00 – 15.00
The Long Mynd is situated to the west of Church Stretton and forms part of the Shropshire Hills AONB (Area of Outstanding Natural Beauty).
It is a large and long, heath and moorland plateau which runs North to South and has steep valleys on its eastern flanks. The highest point on the Long Mynd is Pole Bank at 516m and from the plateau there are stunning views of the Shropshire Hills Area of Outstanding Beauty and the Welsh hills.
It is a landscape with significant archaeology and geology that has been modified by human activity over thousands of years and contains a wealth of wildlife. It is both a Biological and Geological SSSI and is one of the oldest and most important geological sites in the country.
The majority of the Long Mynd is now owned by the National Trust and we are very grateful that they have given permission for it to be used for SINS.
The Long Mynd is generally runnable although there are patches of gorse and scattered trees on the steep valley sides as well as scattered rock or scree. The summit plateau is covered with runnable grassland or variable thickness of heather. The vegetation combined with very steep slopes and potentially large amounts of ascent or descent mean that route choice both general and detailed is significant when navigating across the area.
The following paragraphs give more information about the Landscape and its formation for the Long Mynd, Caer Caradoc and Hope Bowdler Hills.
Landscape on the Long Mynd, Caer Caradoc and Hope Bowdler Hills
The area around Church Stretton has been a prime site for visitors since Victorian times. The town sits at 190m above sea level in a broad valley with The Long Mynd to the west and the Caer Caradoc Hills to the east. The Long Mynd rises to form an undulating plateau at an altitude around 450m and the Caradoc hills form a narrow ridge with a high point of 459 m. Beyond Caer Caradoc the Hope Bowdler Hills make an upland area reaching a lower altitude of 426m.
The Church Stretton Valley originally formed along a fault complex, which runs 60km from South Wales to North Shropshire. Glacial activity has also had a significant impact on the landscape over the last 20000 years but the dominant forces shaping this landscape are much older; dating back to the Pre-Cambrian era 650 million years ago. The Long Mynd side of the valley has been downthrown by around 1000m exposing some of the oldest rocks in Britain on the eastern side of the valley. The Church Stretton fault zone has been active for 600 million years and has produced many famous hills including the Wrekin and Caer Caradoc. The tectonic influence has resulted in a valley much larger than would be expected from the size of streams flowing out of the Church Stretton valley as part of the River Severn catchment.
The Long Mynd is owned by the National Trust and used by local famers with grazing rights for sheep and ponies. The Caradoc Hills are in mixed private ownership and are also used for upland sheep grazing. The upper parts of the Long Mynd have extensive heather cover and were previously used for grouse shooting.
The Stretton villages were all small until the 19th century when the arrival of the railway resulted in significant growth of Church Stretton. Since then there has been further residential building development along the valley bottom as people have settled in the area.
Early human activity left many Iron Age hill forts in Shropshire including one each on Haddon Hill and Caer Caradoc. The forts survive as earth banks and ditches usually surrounding a flat summit. They were built as protected settlements by the Cornovii people who inhabited the area from the 7th century B.C. until just after the Romans arrived. Caradoc or Caractacus, as the Romans called him, may have used the hill and hill fort that carries his name to resist the invaders, but the fort on the summit was already centuries old. Caer is Welsh for castle so the name of the hill also reveals the fluidity of the anglo-welsh border over the centuries. Another feature named after the Celtic freedom fighter is Caractacus’s Cave which lies just outside the summit earth banks; this failed exploration for a mineral vein was named by romantic Victorians who came to Church Stretton in great numbers, because in those less travelled, pre-photographic days, they thought it was like Switzerland and, with the arrival of the railway, it was easier to get to.
Impact of ice and water
The most recent phase of landscape development over the last 2 million years occurred as a series of ice advances and retreats along the Church Stretton fault zone, forming the large valley that exists today. When the main valley held a glacier, melt-water flowing along the edges of the ice cut many channels, such as Cwmdale, on the lower slopes of the western Long Mynd. As this was happening glacial meltwater cut deeply into the Long Mynd forming many steep sided valleys including Carding Mill Valley and others, known locally as batches. The last ice melted around 12000 years ago leaving glacial deposits on much of the top of the Long Mynd and in the bottom of the Church Stretton valley. Melt water washed eroded rock fragments down the batches producing areas of higher, drier ground on which humans built the three settlements known today as All, Church or Little -Stretton.
The Church Stretton faulting is not a long single crack in the earth’s crust. All the way along the fault zone there are many parallel faults running South-West to North-East. Over the last 600 million years the rocks in the fault zone have cracked at right angles to the main fault zone in response to the huge tectonic forces exerted by the main faulting
To the south-east the Caer Caradoc ridge is formed between two parallel faults. The summit ridge rises from the south west to 459m above sea level in a series of steps marked by rocky outcrops. The steps are caused by faults moving different rock types to the surface.
In the area South and East of Caradoc lie Helmeth Hill and Cwms Valley. Helmeth Hill, Cwms and Robins Tump are smaller hills with summits at around 320m. Helmeth Hill is a deciduous wood owned by the Woodland Trust. Cwms Valley separates Caer Caradoc from the Hope Bowdler Hills, it is the drainage zone with a stream flowing south-west towards Church Stretton. The different landscape in this area is a result of movement along the main fault zone which has exposed a thin slice of younger rocks between the much older rocks of Hope Bowdler and Caer Caradoc.
The Hope Bowdler hills are slightly lower than Caradoc but are also used for upland grazing; the smooth slopes show that the area is outside the main Church Stretton fault zone. There are steep valley sides with minor crags and boulders on the steepest ground as well as rock outcrops, notably the Gaer Stone and Battle Stones. Southwards the landscape changes again to mixed farmland where the oldest rocks are covered unconformably by the same types of younger rocks found in the Cwms valley.
Rocks in the area
The youngest rocks in the area are marine limestones, shales and sandstones from the Silurian and Ordovician period around 440-460 million years ago. There are small exposures of the Silurian rocks in the Church Stretton Valley whilst the Ordovician rocks are found the Cwms Valley and further South-East beyond the Hope Bowdler Hills.
The rocks of the Long Mynd are 590-575 million years old from the late Pre-Cambrian era. They are sedimentary sandstones, shales and grits which were laid down in a shallow marine environment. There are also some rock bands which show that active volcanoes were erupting in the area. Volcanic eruptions sent fragments of lava into the air which fell into the sea and mixed with the other sediments producing hard beds of rock called tuffs and they can be traced across the Long Mynd as prominent ridges or waterfalls.
The oldest rocks in the area are on Caer Caradoc and Hope Bowdler, these consist of volcanic lavas, ash deposits, tuffs and intruded dolerite which solidified before it reached the surface. These rocks are 600-650 million years old, from the late Pre-Cambrian era, they were formed as an ancient ocean was closing over a subduction zone. This is the same way that Andes and Cascade mountain ranges are being formed today along the eastern side of the Pacific.