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SHARKHAMPOINT IRON MINE

Last Updated: 22nd Aug 2016

By Chris Popham

1790-1980

The first reliably attributable reference to an iron deposit at Sharkham Point appears to have been made by Henry De la Beche in his memoir of 1839 where he offered little more than a throw away line for what was already a significant local venture:
"A large iron-lode runs nearly east and west from Sharkham Point, near Brixham, to Upton, and was extensively worked towards the end of 1837"(1).

The mining of iron ore at Sharkham Point was however in hand as early as 1790 when a discovery of "considerable quantities of kidney ore" was reported. A century later at the peak period of operation the mine employed 100 workers and shipped ore to South Wales and West Hartlepool for smelting(2).

Iron ore most commonly occurs as the simple oxide [Fe2O3] to which the ancient Greeks gave the name hematite as an allusion to the blood red colour of the solid which takes a slightly purple tint when powdered(3). Hematite may however exhibit a number of different natural forms. Amorphous masses with no obvious crystalline structure may be called iron stone or described as earthy, the former being hard and the latter relatively soft. Kidney ore is another hard form and as the name suggests has the curved appearance of kidneys with a similar red-purple colour and glistening surface. The correct term in the modern convention is botryoidal, the pieces often have multiple pillowed surfaces and in this form the mineral shows a clear crystalline structure as of needles aligned perpendicular to the surfaces. The only additional form to be noted here is micaceous hematite. Named after the mineral mica, the crystals have a hexagonal crystalline structure with a paper thin profile, a grey colour and a bright, lustrous sheen. Nevertheless when powdered this reverts to the blood red, tinged with purple, colour indicative of hematite.

In their paper on the iron mines of Devon(4) Atkinson, Waite and Burt give the iron ore output for Devon as a whole between 1855 and 1913 as 350,662 tons. Whilst they noted this as a sizeable quantity, it was in context less than the output of Hodbarrow Mine in Cumbria in just a single year from the same period. For Sharkhampoint Mine output is listed as 18,913 tons over the same 60 year period.

As always a degree of care is required when interpreting output statistics as some sources report that Sharkhampoint Mine produced in excess of 100,000 tons. This apparent discrepancy may have arisen as Atkinson et. al. gave a separate figure of 114,873 tons for 'Brixham Mine'. To many the only mine in the conventional sense that operated in the Brixham area was Sharkhampoint Mine and so the two become synonymous. However, many mines changed name which was often in no small part to attract investors to a venture that had previously failed and was now being offered for sale. Consequently Brixham Mine and Sharkhampoint Mine may indeed be one and the same. Nevertheless, for the purposes of the statistics a mine is any source of minerals (in this case iron) so 'Brixham Mine' could also include any of the many and various ochre pits that were in operation at the time in Brixham and its surroundings.
Furthermore it was not uncommon practice, if there were several ventures under single management, to move ore from a successful venture to one less successful again in order to boost apparent output figures for the purpose of attracting unwary investors. Therefore it may be that the actual output of Sharkhampoint Mine alone will ever be known. Nevertheless, the scale of the operation at Sharkham Point, evidenced by the area that even in the current day can be seen to have been worked, was extensive and 100,000 tons of output would not be out of place when measured against outputs from other similarly sized ventures over a similar duration.

It has been reported that Sharkhampoint Mine was finally wound up in 1914-15(5). This marked the period when the mining industry across the whole of the south-west region finally reached the point of large scale economic collapse. However, in common with other mines some dump picking may have continued into the 1930s.

The iron deposit at Sharkham Point is said to be unique within the South-West as the hematite has replaced the Devonian age limestone(6). As well as hematite, goethite [-Fe3+O(OH)], limonite [FeO(OH).nH2O] and barite [BaSO4](3) are also found; goethite and limonite both falling under the common umbrella term ‘ochre’. The iron that gave rise to the deposit was most likely leeched by warm groundwater circulating in the Permian age red sand and breccia that once covered the Devonian limestone across a wide area. Put another way, the "Hematite and barite deposits near Sharkham Point are newly regarded as of low temperature cross-course type of mineralisation derived from Permo-Triassic basinal brines." (7)

The geological description of nearby Breakwater Quarry(8) notes that very prominent solution fissures are evident in the limestone, exhibiting flowstone at their margins with a core filling of Permian 'red' sand. It is perfectly possible that the Breakwater sand and Sharkham Point iron deposits have similar origins and that the iron is not replacement of limestone as such but infill of solution fissures. In addition this mechanism would be consistent with descriptions of iron flowstone on the walls of cavities within the mine, this having been deposited prior to the hematite masses in the centre of the fissures.

The mechanism of deposition made the iron ore from Sharkhampoint Mine of particular value as it has relatively high iron content and in some places negligible phosphorous or sulfur content(13). To this end it was sought after by the smelters in South-Wales to be blended with Welsh iron stone to raise the quality of the pig iron. Thereafter the iron was particularly suited to the manufacture of railway track as it shrank less than other iron during cold weather(4).

In addition, paint manufacture may have been another use for the iron ore from Sharkhampoint Mine.

In the 1862 catalogue of the International Exhibition(9) a whole page is given over to a miraculous rust proofing paint that had been invented in 1849 by John Rendall in Brixham and manufactured by Richard Wolston under the banner of 'The Torbay Paint Company Ltd'.

The paint was a mix of ochrous iron (oxides and hydroxides) with linseed oil and turpentine. The initial source of the ochre was that which had been found within the land Wolston owned at Furzham Hill. Later, during a chequered history of paint production in Brixham, ochre was independently sourced from other sites including a large pit off Rea Barn Hill. Wolston's paint works was initially set up at Oxen Cove (now Freshwater Car Park) but a larger rival operation later established in New Road. The site at Oxen Cove and adjacent Overgang Road also functioned as a 'barking yard', where ochre that had been boiled with oak bark (hence the term) and wood tar was painted onto sails as a preservative. This had the aesthetic quality of giving the sails their magnificent red colours.(10)

Torbay Paint was used on both iron and wooden structures. It was reported to give a greater coverage than conventional lead based paint, was also resistant to weather, chemicals and heat, would prevent further corrosion of already rusty iron work and retained its finish longer than other paints. To this end the catalogue entry notes that in 1852 the iron pillars of Brixham Fish Market were painted with Black Torbay Paint and after 10 years beside the harbour the paint was in perfectly sound condition (The metal pillars have since been replaced by, or encased in concrete and the size of the market beside the harbour very much scaled back. However the iron pillars, painted black, can be seen on a postcard that is reproduced in the Brixham Town Design Statement 2010(10).). Given the truly miraculous qualities of this product it is surprising that the Torbay Paint Company ceased trading in 1961.

Throughout its production history the principal iron based raw material for Torbay Paint seems to have been ochre, though there are suggestions that Sharkhampoint Mine may also have provided iron ore as raw material: "Besides its use in the production of iron, the haematite ore was powdered and formed the basis for an anticorrosion paint"(11). (Haematite / hematite spelling. International conventions have come into effect regarding the naming of minerals and elements, hence haematite became hematite simply as a popular simplification and this has been adopted as the convention. Similarly sulphur is now recognised as sulfur and baryte as barite. In the main text the modern convention is used but in quoted text the word form used in original is retained.)

Atkinson et. al. note however that in the period from 1880 to 1913 micaceous hematite was worked in the Bovey Tracey area for the purposes of manufacture of rust resistant paint. This was not the same paint as produced by the Torbay Paint Company and the two should not be confused (Great Rock Mine at Hennock worked until 1969-70(4)).

A history of the various paint companies that manufactured in Brixham has been written by Bridget Howard(12), however her exhaustive study makes only one mention of Sharkhampoint Mine: " supplemented by purchases from the mines on the nearby Sharkham headland, where the ochre (as at Wheal Prosper) was found with the iron ore.". There are meanwhile multiple mentions of other ochre pits used as raw material sources. Consequently it seems at odds that high quality hematite with a prominent demand for iron production would be ground for use in paint when there were other sources of readily available soft ochre for the various paint works, quite literally on the doorstep in one case. However, ochre, when found at Sharkhampoint Mine, may well have been sold either to the paint works in Brixham or transported by coastal schooner to Dartmouth when that briefly became the focus of paint manufacture at the beginning of the 20th century.

The output figures for Sharkhampoint Mine and the destination of the ore is further confused by Dewey(13). Writing in 1919 he notes that:
"From the group of mines at Sharkham Point the output of haematite from 1858 to 1875 was 160,000 tons, and between 1875 and 1915 was smaller and by 1917 it was approximately 4,000 tons [in that one year]”.

He goes on:
“The reserves, at the present rate of output, appear to be sufficient for some years. Most of the ore is sold for paint-making, but some is used for the manufacture of iron."

Thus Dewey appears to be overstating output whilst simultaneously contradicting other accounts by suggesting that most of the output went to paint manufacture. However, by the time he was writing shortly after the mine had closed, it may have been the situation that in the final years paint manufacture had been the principal market.

Included in a table of chemical analyses, Dewey lists 5 hematite samples from Brixham, one being singled out as "paint-ore", noting that this is "soft and brilliant" as distinct from the 4 other samples; 2 of which are described as "soft ore in the form of fine powder" the others as "ore in lumps", these latter being low in phosphorous, with sulphur absent and being therefore "a rich and valuable ore".

It is possible however that Dewey is in error and the paint ore was not perhaps from Brixham, as 'soft and brilliant' is a fitting description for micaceous hematite which has led to it being commonly known as 'specular' or 'shining ore'. As noted, this was mined at Great Rock Mine and others (Kelly, Plumley, Hawkmoor and Shaptor, etc.) near Hennock and was also used for a type of anti-rust paint. Micaceous hematite is formed in a hydrothermal geological setting and would consequently be inconsistent with the deposits at Sharkham Point. Additionally there is no reference to, or current day evidence for this iron mineral type at Sharkham Point.

The confusion may have a simple resolution. Prior to the mid 1870s 'Brixham Mine' as well as a number of other Devon mines; though none of those near Hennock is specifically mentioned, was under the ownership / management of a William Browne. After that time W.H. Hosking emerged as a prominent figure on the Devon mining scene with a controlling share in most of the micaceous hematite mines as well as others in Devon(4). It is not inconceivable then that one of these owners brought samples for analysis from unrelated mines but that the samples became cross-referenced. However, Dewey is only referencing analyses conducted by a third party and the details may simply have been misquoted.

Looking in detail at the analyses one item stands out distinctly between the 5 samples allegedly from Brixham, wherein four contain 'siliceous matter' ranging from 4 to 35% and yet the 'paint ore' contains none. If it is accepted that the Brixham hematites were deposited in fissures from fluids circulating in overlying beds of red sand then some silica content is almost guaranteed. On the other hand, as seen at Great Rock Mine, micaceous hematite is deposited in a hydrothermal setting as thick lodes in granite with no quartz gangue and consequently obtaining a sample from a lode where no silica is present would not be unexpected.

In short therefore, given the interconnectedness of mine ownership and paint manufacture based on iron pigments and the contrasting geological setting of Sharkham Point compared to the area around Hennock the interpretation of the analysis quoted by Dewey must be in question. In turn this may have had a knock on effect to those who have taken these details and suggested that Brixham Mine produced iron ore rather than ochre for paint manufacture.

Dewey also provides a description of the Sharkhampoint Iron Mine site. Of the deposit he writes that:
"There is no true lode, the ore occurring as irregularly-shaped bodies in Middle Devonian limestone. Some of these bodies occupy pockets or what are apparently old solution-cavities. In these cases the junction between the ironstone and the limestone is sharply defined".

And that:

"some of the bodies have the appearance of true lodes, with nearly vertical walls."

This again would be consistent with the tall, vertical, solution cavities evident at Breakwater Quarry.
Of the mine layout Dewey writes:

"In the mine now being worked the adit, which runs southward, is 400 ft. long, and is connected with a shaft at a depth of 78 fathoms from the surface. There are many levels in the mine, but, as all are above adit-level, no trouble from water is experienced."

Dewey’s description is accompanied by this map.


A later description claims there were 6 shafts and 5 quarries with some ore being transported by boats that moored below the mine on "Sharkham Flats"(14). That account goes on to say that in addition ore was transported to a storehouse at Castor Road in Brixham, which would have been approximately ½ the way between the mine and the Torbay Paint Works in New Road.
A review of the merchant ships register of the Port of Brixham notes that a large number of coastal schooners were at one time operating from the port and that during summer months these carried iron from Sharkhampoint Mine "and others nearby" to South Wales returning with cargoes of coal(15). The ships tied up to the quays formed by the quarrying at Sharkham Point and even today mooring rings can been seen in situ. However, the names and locations of the ‘others nearby’ are not given.

The 1906 Revision of the Ordnance Survey 1:2500 map series shows a number of features of the mine at a time corresponding to the peak of the mining activity.

Two adits are shown: the first on the foreshore of St Mary's Bay, the other on the foreshore at the north-east tip of the point. In addition there are three shafts: the first in the quarry considerably to the west of the site adjacent to what may be a building; the other two are within the mine workings on the eastern face of Sharkham Point.

The map shows 6 quarries spread across the point, however one 'Old Limekiln' is marked suggesting that at least some of these quarries were not directly part of the mine. Until the mid-1800s limestone was 'burnt' in the kilns, a process that affected a chemical change on the limestone. Thereafter, when mixed with water this yielded 'quicklime' which served as the equivalent of modern day cement for building mortar and render. Burnt lime was also ploughed into agricultural land to break up the clay texture. No doubt if hematite was found within the quarries it would have been sold on to the mine.



The quarry at the eastern end of the point was undoubtedly the main focus of Sharkhampoint Mine. A track crosses the point, past a long, narrow building and into the mine where it turns southward for a short distance. Where it enters the quarried area of the mine it apparently carries over a branched tram-road by means of a bridge. The tram-road ends on the cliff above the foreshore. In the elbow of the track and tram-road a small building is shown. Implicit in the placement of the name 'Sharkhampoint Mine' is that the long building was the central focus of the mine operation.

In addition to the shafts on the 1906 map the 1865 revision shows a shaft in the centre of the main iron mine quarry workings.
In the years after it closed the mine site was used as the town tip for Brixham(14) and after 1980 was transformed into a nature reserve. Consequently much of the mining heritage has been obscured(16).



2015

Sharkham Point may be reached by road from Higher Brixham by following the brown tourist signs to St Mary's Bay Holiday Camp and then continuing on along the single track road to the car park maintained by Torbay Coast and Countryside Trust. Parking is free, but there is a 6'6" (2m) height restriction barrier and little opportunity to turn around at the barrier. Alternatively, the South-West Coast Path crosses Sharkham Point and it is a very pleasant walk from Berry Head where there is car parking at a charge.

Sharkham Point is to all intents and purposes a square headland that juts due east with the land surface inclined such that the headland has an elevation of 45m-50m above sea level along the southern flank sloping to 20m-25m on the northern side. On the northern side the cliffs are undercut along the foreshore, whilst along the eastern end of the headland there are a number of places where paths lead down to the foreshore. The south-eastern point of the headland has apparently been quarried in such a way as to form a small enclosed harbour at high tide. The southern flank of the headland is a steeply inclined sea cliff with no foreshore.

The macro-geology of the headland is accurately portrayed on the Dewey map. The mudstones to the north are mostly thinly laminated black shales with some interbedded fossiliferous limestone of Middle Devonian age (around 385 million years before the present)(18). The mudstones are extremely soft and are constantly experiencing landslips and erosion. However, Mussel Rock is limestone and not mudstone.

The limestone that constitutes the bulk of the headland is sometimes described as 'dove grey' though in truth mostly red stained by the hematite. In places the limestone appears to be bedded with thicknesses mostly less than 30cm though highly fractured and distorted. Massive reef limestone pieces interrupt the bed sequence and in addition there are thin beds of volcanic rock.
The 'volcanic rock' is mostly dark grey and featureless basaltic lava and tuff and is contemporary with both the limestone and mudstone. However the BGS viewer does not record a volcanic outcrop in the centre of the headland as shown in the Dewey map. The deposit would be within the level of resolution offered by the viewer, but as this area has apparently been quarried the outcrop may have been mostly removed.

One difficulty arising from the account of the mine site given by Dewey that calls into doubt its veracity is that a measurement using the Global Positioning System (GPS) sets the highest point of Sharkham Point at only 210 feet (64m) above ordnance datum (mean sea level 1915-21 at Newlyn, Cornwall(17)). Any part of the mine below sea level would flood unless pumped and in the absence of the option to use water wheels a steam engine would most likely be required. There is no evidence of an engine house at Sharkhampoint and consequently to facilitate natural drainage via the adits, implicit in the Dewey account, the whole of the mine must stand above ordnance datum. Consequently Dewey's figure for the depth of the shaft at 78 fathoms (470 feet) must be wrong.

Despite the inconsistencies, Dewey's map serves as a simple template onto which the present day features may be placed.

A ruined building (A) is located at British Grid Reference SX9357 5477 (50°22'59.15"N, 3°29'54.15"W), where it nestles into the gentle slope. Approximately square and 6m on each side, the walls are of solid construction, primarily of limestone, and up to 2m high in places [Fig.1]. The building is sub-divided into two almost equal rooms, aligned north-north-west, both with a doorway in the northward facing wall. The seaward room has in addition a window looking out over the bay with a chimney breast in the same wall. This is clearly the building shown on the 1906 OS Map within the main mine excavation and may have been an office or miners dry, with a store to the rear.

As this ruin provides a focal point within what remains of the site the other preserved features are referenced in relation to it.
Directly north of the building at no more than 10m is a finger dump of waste [Fig.2], in turn approximately 10m along the ridge, ending in a drop to the foreshore. This is the elevated end of the tram-road and is comprised of blocky limestone consistent with quarry excavation waste, constructed presumably so that further waste could be dumped onto the foreshore.
The main bays of the quarry within the mine where the tram-road originated appear to have been partly filled by the tipping operation and are now covered by thick undergrowth.

The track seen on the maps passes the ruin on the north and east sides. Where it passes to the north it is quite steeply inclined towards the shore and where the tram-road would have crossed it the finger dump is supported by a curved wall, whilst on the quarry side there appears to be a pier of masonry. The implication is that the tram-road crossed over the track on a bridge between these two points contrary to the OS 1906 map which has the track crossing the tram-road.

On the eastern side the track opens out to form level space with a low wall of loose fitting blocks on the side with the ruin. This retains a debris pile of small rock fragments [Fig3.] many of which are hematite rich so it is tempting to speculate that this may be spalling waste (fragments of rock chipped away from valuable ore), but as most nearly every rock, boulder and cliff face going south from this area is rich in hematite it may simply be excavation waste.

The track continues and turns west beside some stunted willow trees that grow from a boggy patch of ground. The track quickly becomes a narrow, ever deepening cutting that twists around a shoulder of ground and ends at an adit entrance. The portal is pyramidal in shape with a high step of fallen debris. Inside the floor drops steeply, but almost immediately the adit is blocked by a mound of soft clay debris; the accessible extent being no more than 4m. This is not shown on the OS maps.

There are two mineralised features in the adit. The first is a strip in the roof and seemingly against a footwall [Fig.4]. Anywhere else this might be regarded as a mineralised vein though here it has only a slightly different, more silvery, colour compared with the walls and floor of the adit suggesting a higher proportion of hematite without being sufficient to call it ochre and certainly not iron ore in any meaningful sense. Nevertheless to any hard rock miner it is certainly a feature that might be expected to lead to a more highly mineralised pocket.

The other feature is just inside the adit entrance where it appears to branch off to the left (southwards) but immediately ends in a blank wall dotted with yellow ochrous spots [Fig.5].

At a distance of 85m due north of the ruin is a level area of foreshore (B) approximately 5m above present day spring tide high water mark. It is uncertain if the open space was made during the excavation of the mine or is a remnant of a natural wave cut platform dating from the Pleistocene period (19), but it is possibly the area known as Sharkham Flat. Two iron rings, each 120mm diameter remain fixed into the limestone and may well have been used for mooring boats [Fig.6]. Close by is an area where some masonry remains despite time and tide and this may possibly have been a quay wall. However, when seen at low tide the foreshore is a jumble of rocks that surely would have prohibited the safe mooring of any vessel.

An adit has been driven into the hillside off Sharkham Flat with the portal at the level of the platform. It is over 1m in width and 1.5m high throughout and extends 'on the level' 15m into the hillside [Fig.7]. Along the full length the drive is through thin limestone beds now coated with soft hematite 'clay' that has presumably weathered from the rock. The adit ends abruptly and there is no evidence of any ore extraction. Consequently it may have been a trial for ore, or, an unfinished drainage adit as the entrance is close to sea level which would have facilitated most water flow.

Beside the adit entrance is a large, rough boulder which contains plenty of hematite in soft earthy masses, but also barite as crystals.

Between the adit portal and the sea a gully has been excavated into the limestone platform, progressively deepening to at least 2.5m at the seaward end. The gulley aligns directly with the adit entrance and a very prominent iron stained mass in the cliff on the far side of St Mary's Bay [Fig.8]. This is clearly not the east-west lode mentioned by De la Beche but does suggest that the mineralization may have been more extensive in the past and may even have cut through the mudstone. However, this would be inconsistent with the idea that the hematite was deposited in solution fissures in the limestone so whilst a striking association it is probably just coincidental. If however the gulley contained iron ore that was mined out then that would in turn suggest the adit was a trial for ore [Fig.9]. Both the adit and the linear excavation in the foreshore are shown on the 1906 OS map.




Fig. 1. The ruined building, the focus of the remaining mine site. This angle of view shows the north facing doors though the tree obscures the dividing wall.




Fig. 2. The finger dump near the building along which the tram-road ran, enabling mine waste to be tipped onto the foreshore of St Mary's Bay.



Fig. 3. Part of the retaining wall holding back small rubble.




Fig. 4. The shallow adit with apparent mineralized vein resting against a footwall.




Fig. 5. Yellow ochre in the shallow adit and also pinky-white clusters of barite crystals to the right. Field of view approximately 0.5m




Fig. 6. Mooring rings fixed into the limestone of 'Sharkham Flat'.




Fig. 7. The adit at Sharkham Flat trends with the same orientation as the 'lode' pictured below.




Fig. 8. The mined out 'lode' at Sharkham Flat and the iron stained cliff on the far side of St Mary's Bay.


170m due west of the ruin is a modest barn like building (C) with a corrugated iron roof. This corresponds to the building marked on both the 1865 and 1906 OS maps and the Dewey map beside the dotted track and beneath the words 'Sharkhampoint Mine'. On the 1865 OS map this is shown as a cluster of buildings, but was evidently later remodelled into a single long, narrow building. The original walls are of a similar construction to the small ruined building though the tops of the walls and roof have been rebuilt. The roofed part is approximately 4m by 8m long with an equal unroofed distance to the original eastern gable end wall. On the assumption that this was a significant part of the mine operation it was no doubt the mine captain's office, count house, store and may even have housed a blacksmiths shop and sawmill, all essential aspects of mining in the 19th century.

For a distance of approximately 120m-150m south of the ruin the ground has been extensively quarried (D) and all about are exposed patches of cliff face or massive loose boulders comprised almost entirely of earthy red hematite. In places limestone is exposed and it is distinctly separated from the hematite with some of the surfaces having patches of calcite flowstone. In other places it appears that the hematite and limestone grade into each other [Fig.10] possibly either as a result of gradual dissolution and softening of the limestone with hematite replacement or simply deep penetrating hematite stain into the limestone.

One massive boulder dominates this area of quarrying and over the surface patches of bladed barite crystals are evident along with botryoidal dark brown, soft, goethite and small cavities filled with friable limonite. The 1865 OS map places a shaft at this location enclosed within a rectangular shaft collar, whilst at a short distance to the north marks a circular feature about where the track on the 1906 revision ends. Consequently the circular feature on the map corresponds accurately to the shallow, boggy depression observed in the present day and that being the case the massive boulder occupies the space between the boggy ground and the shaft. It seems unlikely that the mine would have developed around the boulder as it undoubtedly contains iron ore, could it therefore be that the boulder was tumbled from the quarry face either deliberately at a late stage in the mining operation or has fallen subsequently of its own volition?

On the crest of the hillside above the south-western end of the quarry is an unmistakable shaft collar (E) beside one of the footpaths. The seaward side is steeply banked with a near vertical drop on the outside into the quarry whilst the remainder is level to the ground. The shaft has been filled leaving only a shallow conical depression.

There is no clear evidence to give the exact location of any of the three other known shafts. The one in the car park and the building beside it have been covered over with tip waste. Of the two within the quarry their locations are possibly marked by levelled spaces but there is no incontrovertible evidence. That leaves 2 shafts where no location information is known.

The south-eastern tip of the headland has a pronounced raised wave cut platform and two deeply incised quarry bays where evidence of hematite is again extensive.

The remainder of the headland is taken up with a heath of bracken, furze and grass and the extensive car park. The car park is partly surfaced with concrete and partly with tarmacadam, possibly residual from the use as a tip, whilst in other parts the limestone bedrock is exposed. The limestone has a distinct bedding structure interspersed with crushed and compacted limestone (however note that De la Beche includes a block diagram in his text to illustrate that in places the limestone also has cleavage and given the wear and tear to the surface it may be that the apparent beds are in fact cleavage planes).

Two further adits are in evidence at the present time. The first is 210m north-west of the ruin in a small bay at the foot of the cliffs (F) and can be reached from the beach in St Mary's Bay, but only at low water on a spring tide. The entrance is piled with storm thrown boulders after which the adit opens into a small chamber and then ducks under a low hanging section of roof where again the floor is piled with debris [Fig.11] and this make it a tighter access than the portal suggests.

Beyond this the adit is deeply flooded and stretches back into the hillside in a straight line trending due south for approximately 50m, an alignment that would take it very close to, if not directly underneath the barn like building on the hillside above (Entry to any underground workings should only be undertaken with the direct participation of properly equipped and experienced persons.). The floor slopes gently upward so that the inner 20m is not covered by water. Throughout, the passage is approximately 1.2m high and 1.5m wide and driven through sound rock. The passage ends where some timbering has collapsed completely blocking the adit [Fig.12] though the appearance is that the adit continues. Just before the collapse a side passage extending about 4m is driven north-west.

The only evidence that hematite has been extracted from the adit in terms of lateral widening or raising the roof (stopeing) is the chamber just inside the portal where in addition to excavating into the roof a very short eastward drive has been made. Throughout though, everything is coated in thick, dark red, hematite mud.

If this is the adit that Dewey reported as trending due south and 400 feet long, then there must indeed be an extension beyond the
collapse and if 400 feet in length it would have extended a short distance beyond the barn on the hillside above.

The other adit (G) is seen 400m north-west of the ruin, beside the steps to the beach. This is shown on the 1906 OS map though apparently the steps are more recent. The entrance is piled with debris and only 2m of roof is visible after which the adit is completely flooded. A small trickle of water constantly runs from the adit entrance and across the beach. That this may once have been substantial is perhaps indicated by the unmistakable piece of iron tram rail, approximately 60cm in length, once seen wedged between 2 large boulders on the foreshore below the adit entrance. Other artefacts may well be similarly placed but the nature of the beach is that for most of the time the whole area is covered in sand so that the rock basement is only exposed by a rare combination of waves, currents and tides.

The foreshore between the steps and the long adit with the timbering is a jumbled mix of limestone and hematite boulders often streaked or blotched variously with white barite or calcite. However, in the cliff face just beyond the end of the beach there is a substantial zone composed of alternating layers of calcite and layers of hematite. If the calcite was deposited as

flowstone, and it has all the appearance of this, then deposition must have been relatively slow, perhaps indicating a period of low rainfall. Maybe the hematite layers represent climatic change but that could be to either a period of higher or lower rainfall. That the hematite in some cases did form as a flowstone is evidenced by the piece shown in Fig.13.
Botryoidal hematite was reported as one of the ores from the mine and on the foreshore of St Mary’s Bay, when the sand has been stripped away, the dense mineral is occasionally seen where it has been caught between rocks which have prevented it being washed out to sea.

Logically, it is expected that the cliffs below the mine would have been the origin of these pieces of hematite, and this may well have been the case, with transport to the beach by waves and currents. However, it appears that this did not occur recently as the hematite sometimes has beach sand within the hollows of the inverse surface firmly adhered by calcite cement (which dissolves actively in dilute hydrochloric acid, a positive indication that it is calcite) [Fig.14].

Clearly cementing of the sand and hematite would be inconsistent with the pieces tumbling amongst the foreshore stones from the cliffs to the beach over a distance in excess of 300m. Similarly, the value of the ore would preclude it having been dumped where it is now found during the lifetime of the mine and again the sand would not adhere in the high energy environment of the beach.
Consequently the implication is that the hematite has lain for a period in an undisturbed location, buried in beach sand, yet subject to percolating water that has delivered the calcite-hematite cement.

Further inspection of the present day foreshore when it is denuded of sand etc. reveals in places discrete rafts of cemented sand of the same colour and consistency as that attached to the hematite [Fig.15]. When treated with dilute acid the cemented sand releases mudstone and quartz fragments in sizes from microscopic grains to pebble sized clasts. The treatment does however dissolve any limestone fragments, but they are presumably present as the sand encloses large, rounded, boulders of limestone. The cement matrix has no discernable structure and the presence of hematite has given it an orange-red colour. Earthy hematite pebbles up to the size of a football are abundant in this lithified beach matrix and though kidney ore has not been seen it is reasonable to assume it is present and that erosion releases pieces onto the beach.

The question then arises as to the date of the fossil beach deposit? At the present time it is clear to see that the shoreline at St Mary's Bay is being eroded at a very rapid rate into the mudstones. Orme details raised beaches and strandlines at St Mary's Bay but dates those to the Pleistocene 125000 years before present and the observed rate of erosion would tend to suggest this is far too distant for any relic to have survived.

In the 'recent' past, one possibility would be the inter-glacial period 11000 to 10000 years before present. 15000 years ago, towards the end of the Devensian, the glacial ice sheet reached far down the Irish Sea and across the UK mainland between South Wales and The Wash(20). This produced periglacial conditions widely evidenced along the South Devon coast such as the frost fingers in solifluxion sediments visible at Bovisand Beach on the shore of Plymouth Sound, and would undoubtedly have created frost shattered scree from the cliffs of Sharkham Point.

During the interglacial period when the ice sheet melted and sea level rose again the fragments may have been sifted and sorted and carried in to the beach. Whilst not as hard as quartz beach sand by the Mohs' scale (5-6 for hematite vs 7 for quartz) the density of hematite would tend to ensure that it was transported only infrequently during high energy storm events. Furthermore the energy of a wave is greatest as it breaks on the beach, thus denser material is progressively moved to the back beach as the energy of the backwash is insufficient to draw pieces back to the surf line. Consequently, once on the back beach hematite would settle rapidly into crevices and get covered by sand exactly as happens on the present day beach, protecting it from mechanical attrition.

During the Loch Lomond stadial 11000 years before present the ice sheets re-advanced for a period of around 1000 years and the new beach would have been left high and dry as sea level again fell. The sand may then have become lithified as percolating water delivered the calcite-hematite cement, a process potentially enhanced by compression if coarse cliff-fall material was deposited as scree over the beach layer.

When the sea again returned the resulting sandstone proved resistant to erosion by a combination of features: initially it may have been covered by overburden, once exposed the cement may have given it high strength, the large boulders included in it have supported it and dissipated larger mechanical blows and again for most of the time it is covered by modern day beach. Thus small fragments have survived to the present day though its future is of course finite*.













* St Mary's Bay foreshore is scheduled as a Site of Special Scientific Interest. The schedule normally permits limited collection of geological specimens, so long as there is no detrimental damage that would detract from the appreciation by others and conditional upon the samples being for educational or research purposes. English Nature has imposed an additional blanket ban on collecting without their authority. This seems counterproductive given the rate of erosion, as samples loose on the beach will quickly be broken up by the waves and lost forever much to the detriment on any further investigation.




Fig. 9. The excavated gully at Sharkham Flat leading directly to the adit portal at the foot of the grassy slope. On the skyline is the finger dump pictured in Fig.2.



Fig. 10. Limestone impregnated with or being replaced by red hematite in a face exposed by quarrying. Vertical field of view approximately 1m.





Fig . 11. Entrance to the beach level adit on the St Mary's Bay side of Sharkham Point. Hematite is clearly visible in the cliff face above the portal.





Fig. 12. Timbering within the beach adit.




Fig. 13. Hematite showing the rippled surface characteristic that might commonly be associated with flowstone deposition.



Fig. 14. Botryoidal 'kidney ore' hematite with sand grains adhered. The grains are either white quartz or grey mudstone fixed by yellow calcite 'cement'.






Fig. 15. Lithified beach sand, potentially the source of the hematite shown in Fig.14, firmly adhered onto the limestone basement.


COMMENTS
Sharkhampoint (or Sharkham) Iron Mine was worked for around 125 years and employed at its peak 100 workers. Whilst this does not place it on the scale of some other Devon mines it was nevertheless a significant venture when set in the context of a local population in Brixham of just 8000 towards the end of the 19th century(7). It seems extraordinary therefore that its heritage remains obscure to the extent that in his meticulous memoir 'The Metalliferous Mining Region of the South-West of England' (21), Dines completely omits any mention under any of the names: Sharkhampoint, Sharkham or, Brixham Mine.

That iron ore was sent to smelters in South Wales is certain and it seems very likely that ochre would have been sold to the paint companies in Brixham. However, when abundant soft ochre was available locally it seems less certain that quality iron ore would be sold to the paint companies where it would require grinding before use, unless the resulting pigment had a specialist application not served by the use of ochre.

There is however the interesting possibility that it was not hematite that was taken to be ground for paint but barite, which also occurs abundantly at Sharkham Point alongside the hematite, its means of deposition also being from circulating fluids, and one of the major uses for barite was traditionally as a pigment in white paint(22). This would simultaneously address the questions of why an ore considered valuable for iron making would be used for paint and why go to the expense of grinding iron ore when soft ochre was available and further, why transport ore from Sharkhampoint Mine to Brixham when ochre was available nearer the paint works? Whether the pink tint from the associated hematite could be separated is unknown, but given that many Devon farmhouses are painted pink externally, as any other colour quickly becomes stained pink from the hematite in the red soil, a pink tint to the paint may not have been a consideration.

There were probably a number of factors that contributed to the closure of the mine. Many of the defunct mines of Devon and Cornwall were prospected during the years of the 1914-18 war (and again under similar circumstances in 1939-45) but few raised any ore. Skilled manpower was in short supply and even after hostilities ceased formerly active mines found it difficult to obtain reliable and motivated workers.

In addition cheap imports of many metal ores such as tin, copper and iron, or the import of metals as raw materials impacted detrimentally on the economic viability of many mines unless they were exploiting a material in some way unique. In the case of Sharkhampoint Mine the iron ore output was low and the cost involved in the transport of the ore to the smelters in South Wales may have been prohibitively high.

As the Torbay Paint Company owned ochre pits off Rea Barn Road, much closer to the works than Sharkham Point, it did not need to outsource. The paint works may have taken hematite on occasion but by any account this was only a small quantity and consequently even small sales of ochre were not going to be sufficient to keep the mine afloat.

‘Afloat’ may also have been a very literal factor in the closure. Whilst much of the exploitation was evidently open cast quarrying as evidenced by the present appearance, some was underground where the mine was drained by adits onto the foreshore. Further deep mining below sea level would have required the installation and running of a pumping engine, a cost that could not perhaps be justified given that the value of locally mined iron ore was slumping due to cheap imports. Consequently it may be the case that there are still reserves at depth.

The argument against reserves at depth is that if the iron deposits were indeed primarily restricted to infill of solution fissures then these would be expected to taper out at depth like those in Breakwater Quarry. As noted, the limestone surface is exposed in the car park 40m above sea level so there may not be any significant fissures to hold reserves below the depth that has already been accessed.

What remains particularly obscure however is an accurate site description from either during active operations or when the mine closed. Nor are descriptions available from immediately prior to the use of the site as a tip as all the planning archives from that time have been discarded. Thus given the subsequent restoration to a nature reserve it seems likely that the location of all 6 shafts and which quarries were worked for iron ore will remain unknown.

These observations of the mine site were made over the winters of 2014-'15 and 2015-'16 when vegetation was at its least and were as comprehensive as was possible. It should be noted however that much of the heritage that was not destroyed by tipping in the 1950s has been reclaimed by natural processes. Consequently within 20 years it seems likely that little of note will remain standing or will be visible to those with an interest in the unique geology of the site. It is hoped then that this account will serve as an enduring record of this once significant local industry and that it will also draw the attention of those overseeing its SSSI and heritage status to the need for: restorative work to the area centred on the small ruined building and tram way, clearing of vegetation from quarry faces to reveal the unique depositional features, and investigation of the site of the building and shaft collar in the car park with the potential to fully excavate the features.


REFERENCES
1. "Report on the Geology of Cornwall, Devon and west Somerset", Henry T. De la Beche, F.R.S. (1839), Originally published by Longman, Orme, Brown, Green and Longmans on behalf of Her Majesty's Treasury and now available as a free downloadable eBook from Google on-line, p302
2. "Rocks and Fossils of Brixham" (2015), Chris Proctor, Philip L Armitage & Janet Pettit, Brixham Heritage Museum, New Road, Brixham, TQ5 8LZ.
3. "Mindat.org", www.mindat.org
4. "The Iron ore Mining Industry in Devon", M. Atkinson, P. Waite and R. Burt, (1980-82), Northern Mine Research Society, Sheffield, U.K., British Mining No19, pp27-33.
5. "Brixham Hematite Iron Mining Company Ltd. Truro Registry Company No 43. Incorporated 1865. Dissolved by 1914", Reference BT 286/85, Records of the Board of Trade and of successor and related bodies, The National Archives, Kew, London. Only the title page is available in digitized form.
6. "Berry Head to Sharkham Point", The Educational Register of Geological Sites, maintained by Devon County Council, County Hall, Exeter EX2 4QW, and available on-line through the DCC web site.
7. British Geological Survey Annual Report 1998-1999, British Geological Survey, Keyworth, Nottingham.
8. "Breakwater Quarry", The Educational Register of Geological Sites, maintained by Devon County Council, County Hall, Exeter EX2 4QW, and available on-line through the DCC web site.
9. Item 411, "Wolston, Richard Walter, Brixham, Devonshire. Wolston's Torbay iron paints and composition for coating materials underwater." Catalogue of the international Exhibition 1862, Cambridge University Press, page 35. (Available as a one page excerpt by searching on-line using the terms 'International Exhibition 1862 Wolston'.)
10. “Brixham Town Design Statement” (2010), Draft Statement, published by Brixham Town Council, p8.
11. "Geology in Devon", item 17, page 25, Devon County Council, County Hall, Exeter EX2 4QW, ISBN: 1-85522-968-4
12. "The Torbay Paint Company", Bridget Howard (2000), Dartmouth History Research Group, ISBN 1 899011 18 8, Paper 27, p9.
13. "Special Reports on the Mineral Resources of Great Britain", T.C. Cantrill, R.L. Sherlock and Henry Dewey, (1919), Memoirs of the Geological Survery Vol IX - Iron Ores, His Majesty's Stationary Office, London, Chp V "South Devon and Cornwall", pp47-54.
14. "Before Pontins (1938–1961)", part of the on-line resource "Sharkham Village" maintained by Sharkham Residents association.
15. "Merchant Schooners" John Pike, part of the on-line resource "Caught in the Web - Bytes of Torbay's Past" maintained by Torbay Council.
16. “Restore Tip As Public Space”, (1980), Torbay Council on-line planning portal, application reference P/1980/1203.
17. "A guide to coordinate systems in Great Britain", (2015), The Ordnance Survey, Southampton, UK, p25
18. "Geology Viewer of Britain", British Geological Society on-line resource.
19. "The Raised Beaches and Strandlines of South Devon", A.R. Orme (1960), Department of Geography, University of Birmingham, UK (This is a document sourced on-line via the Field Studies Council however the exact reference is obscure).
20. "The Geology of Britain", Peter Toghill, (2000), Airlife Publishing Ltd, Shrewsbury, England. ISBN 1 84037 404 7, pp176-7.
21. "The Metalliferous Mining Region of the South-West of England", (1956), H.G. Dines, Her Majesty's Stationary Office, London.
22. "Rutley's Elements of Mineralogy", revised by C.D. Gribble, (1988, 27th Edition), Unwin Hyman, London. ISBN 0-045-49011-2.





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Comments

Can't see any of your figures.

Dennis Tryon
23rd Aug 2016 6:25pm

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