This report is a bit history heavy and report/pic light.
The History Stuff
Cymbeline: (also known as Cunobeline "Strong Dog", or Cunobelinus) was "King of the Britons" roughly AD 9 - AD 40 as a client-king of the Roman Empire (outer Roman Empire was run kind of like a franchise model). Most notable due to the large number of coins discovered bearing his head/name. See: https://en.wikipedia.org/wiki/Cunobeline
Gold: Chemical element with the symbol Au (from Latin: aurum) and atomic number 79, making it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile metal in a pure form with absolutely no ******* chance of being discovered in Essex. See: https://en.wikipedia.org/wiki/Gold
~~~~~~~~~~~~~
Essex isn't a county people associate with underground mining. There are many examples of aggregate, sand, brick clay and in a few locations chalk, exploited opencast. CANUK even own a licence for hydrocarbon exploitation at Little Chishill close to the border with Cambridgeshire, with exploration wells drilled by BP in 1966. But no commercially viable sources of oil/gas have been discovered to date. See https://www2.bgs.ac.uk/mineralsuk/download/england/essexMap.pdf
Geology
I'm not a geologist so correct me as needed. South Essex is dominated by a load of stuff dumped by the bottom edge of glaciers after a series of glacial events which is why it's a great area for various sand and gravel works. One example and I've seen it myself is an approx. 1 ton boulder outside a visitor centre in South West Essex which was found in a nearby gravel pit. The boulder is a very specific rock type and without doubt it definitely originated on the Whin Sill in County Durham before it was found buried in an Essex gravel works. Incidentally massive blocks are very occasionally carried by glaciers. This transport mechanism explains a natural occurrence of large lumps of rock from Presli Hills, Wales - being found in Wiltshire, especially when you look at the map of directions and limits of glaciation! So maybe Stonehenge builders didn't need the help of aliens to transport the heel-stone rock for them after all..? but that's a whole different report
See: https://brian-mountainman.blogspot.com/2012/04/chunk-of-whin-sill-in-london.html
Underneath that alluvium cover (sands/gravel/lots of clay/similar cr*p) are layers of "sand". This is "Thanet Sand" and isn't a rock-hard sandstone but isn't sand like on a beach, think of it more as a very wimpy soft rock than being "sand". Underneath the Thanet Sand is chalk - lots of chalk, a massive body of chalk.
Mining
However... in South West Essex there is a long history of small scale underground mining going back to at least as far as Roman times. Mining in the Kent and Essex area was described in some detail by Pliny the Elder in AD 70 and how chalk was spread on Clay fields at 8 tonnes per acre and how long one application lasted on the fields. This loaming process was to "sweeten" the soils. He says of the mining process:
"...the chalk is sought from a deep place, wells being frequently sunk to 100ft, narrowed at the mouth, the vein spreading out within as in mines. This is the kind most used in Britain. It lasts for 80 years and there is no instance of anyone who has put it on twice in his lifetime..."
It is also reasonable to believe that there were underground sand mines in Essex in the past, but as far as I know, none exist today. Until surfaced roads became common, cart wheels would sink in the mud so transporting sand, chalk, gravel, brick clay or any heavy materials for even a short distance was undesirable, so many small mines existed supplying their immediate areas.
Cymbeline's Gold Mines
The exact history and dating and even purpose of what's known as Cymbeline's Gold mines is speculative and different explanations have fallen in and out of favour. Around the time of Henry IV (1367-1413) there was a widespread belief that the large number of deep shafts in the ground at Hangman's Wood in Thurrock were the remains of Cymbeline's Gold mines and the secret of his wealth and fame. If anything is to be learnt from mining history, it's that wild stories of hidden wealth always originate from someone pulling some kind of scam. The who and what for that scam/story is unknown, but we know that there were a *lot* of holes in the ground, at least 70 and that they were ancient and of unknown use/origin during by the late 1300s. The assumption is due to the numbers of them, they must be made over a period of time and worked much earlier than the 1300s for their use to be forgotten by then. Perhaps Roman times and probably not later than 1200s. Quite likely they are >1,000 years old.
They used to be a local curiosity with The Essex Field Club exploring then in 1887 when 15 shafts were explored also a trip by a Scout group in the 1970s (before health and safety! https://www.thurrockgazette.co.uk/news/10375980.were-going-underground/). Many were badly capped by throwing a tree stump into the top of shaft and covering with earth, so now the stumps rotted there are many left plugged with just earth! many have collapsed and the dene holes remaining aren't particularly stable. There are maybe 5 still existing on that site? but only 3 remaining known to have open shafts. In 1985 Hangman's Woods Dene Holes and surround were classified as SSSI due to their importance to brown long eared bats, Natterer's bats and Daubenton's bats and they are left open but securely fenced off.
In theory you can apply for permission to enter them, but due to health and safety whatnot I don't fancy your chances of going with permission unless you are doing some official bat survey (don't visit any site where bats are suspected during October to April hibernation period, don't disturb bats!) As far as I can tell, this site has had very few visits since 1985 apart from a KURG survey around then and some bat monitoring on a few occasions since.
Dene Holes versus Chalk Wells
Generally, people use the term Dene hole to refer to a narrow vertical shaft (maybe 3 foot diameter) that descends between 30-90 deep to underground chambers that radiate from the shaft base, arranged a bit like clover leaves (double trefoil). In *theory* great care was taken that adjacent holes didn't break into each other to help maintain pillars to support the cavities/stalls otherwise it would be even more unstable - this wasn't the experience of my report. The shafts have scoops in the "sand" like a staircase and back-and-footing using the scoops was the miners' method to enter/exit. These are thought to have all been constructed much between Roman times (or earlier) up to the 1300s. There aren't any real artefacts or way to date them, some appear to have antler pick marks in roof (not from metal tools) but exact dating is speculation.
Chalk Wells are a much wider shaft, without any steps/scoops leading down to a bell shaped widening at the base. These are made much later and thought to all be after 1700 and the last known example was made between 1904-1908 in Kent. Entrance and exit was to be raised/lowered in a basket with rope. These were generally for extraction of chalk to burn for lime.
Based on this distinction the holes in Hangman's wood are Dene Holes, not Chalk Wells.
Diagram taken from subbrit (linked below)
What were the Dene holes for?
Cult of Mithras altars, smugglers' hoard, grain stores, royal gold mine, flint source (many don't have the right kind of flint, for flint use), hiding places, underground housing - all have been given as explanations and none seem very likely. The only plausible explanation is mining chalk for loaming nearby fields, as historically documented by Pliny the Elder. But never let common sense get in the way of a good story. Rather than some chalk mine I'm describing my exploration of "Cymbeline's Gold Mines", so much classier!
Diagrams, explanations and further reading on Dene holes see:
kurg.org.uk
Continued....
The History Stuff
Cymbeline: (also known as Cunobeline "Strong Dog", or Cunobelinus) was "King of the Britons" roughly AD 9 - AD 40 as a client-king of the Roman Empire (outer Roman Empire was run kind of like a franchise model). Most notable due to the large number of coins discovered bearing his head/name. See: https://en.wikipedia.org/wiki/Cunobeline
Gold: Chemical element with the symbol Au (from Latin: aurum) and atomic number 79, making it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile metal in a pure form with absolutely no ******* chance of being discovered in Essex. See: https://en.wikipedia.org/wiki/Gold
~~~~~~~~~~~~~
Essex isn't a county people associate with underground mining. There are many examples of aggregate, sand, brick clay and in a few locations chalk, exploited opencast. CANUK even own a licence for hydrocarbon exploitation at Little Chishill close to the border with Cambridgeshire, with exploration wells drilled by BP in 1966. But no commercially viable sources of oil/gas have been discovered to date. See https://www2.bgs.ac.uk/mineralsuk/download/england/essexMap.pdf
Geology
I'm not a geologist so correct me as needed. South Essex is dominated by a load of stuff dumped by the bottom edge of glaciers after a series of glacial events which is why it's a great area for various sand and gravel works. One example and I've seen it myself is an approx. 1 ton boulder outside a visitor centre in South West Essex which was found in a nearby gravel pit. The boulder is a very specific rock type and without doubt it definitely originated on the Whin Sill in County Durham before it was found buried in an Essex gravel works. Incidentally massive blocks are very occasionally carried by glaciers. This transport mechanism explains a natural occurrence of large lumps of rock from Presli Hills, Wales - being found in Wiltshire, especially when you look at the map of directions and limits of glaciation! So maybe Stonehenge builders didn't need the help of aliens to transport the heel-stone rock for them after all..? but that's a whole different report
See: https://brian-mountainman.blogspot.com/2012/04/chunk-of-whin-sill-in-london.htmlUnderneath that alluvium cover (sands/gravel/lots of clay/similar cr*p) are layers of "sand". This is "Thanet Sand" and isn't a rock-hard sandstone but isn't sand like on a beach, think of it more as a very wimpy soft rock than being "sand". Underneath the Thanet Sand is chalk - lots of chalk, a massive body of chalk.
Mining
However... in South West Essex there is a long history of small scale underground mining going back to at least as far as Roman times. Mining in the Kent and Essex area was described in some detail by Pliny the Elder in AD 70 and how chalk was spread on Clay fields at 8 tonnes per acre and how long one application lasted on the fields. This loaming process was to "sweeten" the soils. He says of the mining process:
"...the chalk is sought from a deep place, wells being frequently sunk to 100ft, narrowed at the mouth, the vein spreading out within as in mines. This is the kind most used in Britain. It lasts for 80 years and there is no instance of anyone who has put it on twice in his lifetime..."
It is also reasonable to believe that there were underground sand mines in Essex in the past, but as far as I know, none exist today. Until surfaced roads became common, cart wheels would sink in the mud so transporting sand, chalk, gravel, brick clay or any heavy materials for even a short distance was undesirable, so many small mines existed supplying their immediate areas.
Cymbeline's Gold Mines
The exact history and dating and even purpose of what's known as Cymbeline's Gold mines is speculative and different explanations have fallen in and out of favour. Around the time of Henry IV (1367-1413) there was a widespread belief that the large number of deep shafts in the ground at Hangman's Wood in Thurrock were the remains of Cymbeline's Gold mines and the secret of his wealth and fame. If anything is to be learnt from mining history, it's that wild stories of hidden wealth always originate from someone pulling some kind of scam. The who and what for that scam/story is unknown, but we know that there were a *lot* of holes in the ground, at least 70 and that they were ancient and of unknown use/origin during by the late 1300s. The assumption is due to the numbers of them, they must be made over a period of time and worked much earlier than the 1300s for their use to be forgotten by then. Perhaps Roman times and probably not later than 1200s. Quite likely they are >1,000 years old.
They used to be a local curiosity with The Essex Field Club exploring then in 1887 when 15 shafts were explored also a trip by a Scout group in the 1970s (before health and safety! https://www.thurrockgazette.co.uk/news/10375980.were-going-underground/). Many were badly capped by throwing a tree stump into the top of shaft and covering with earth, so now the stumps rotted there are many left plugged with just earth! many have collapsed and the dene holes remaining aren't particularly stable. There are maybe 5 still existing on that site? but only 3 remaining known to have open shafts. In 1985 Hangman's Woods Dene Holes and surround were classified as SSSI due to their importance to brown long eared bats, Natterer's bats and Daubenton's bats and they are left open but securely fenced off.
In theory you can apply for permission to enter them, but due to health and safety whatnot I don't fancy your chances of going with permission unless you are doing some official bat survey (don't visit any site where bats are suspected during October to April hibernation period, don't disturb bats!) As far as I can tell, this site has had very few visits since 1985 apart from a KURG survey around then and some bat monitoring on a few occasions since.
Dene Holes versus Chalk Wells
Generally, people use the term Dene hole to refer to a narrow vertical shaft (maybe 3 foot diameter) that descends between 30-90 deep to underground chambers that radiate from the shaft base, arranged a bit like clover leaves (double trefoil). In *theory* great care was taken that adjacent holes didn't break into each other to help maintain pillars to support the cavities/stalls otherwise it would be even more unstable - this wasn't the experience of my report. The shafts have scoops in the "sand" like a staircase and back-and-footing using the scoops was the miners' method to enter/exit. These are thought to have all been constructed much between Roman times (or earlier) up to the 1300s. There aren't any real artefacts or way to date them, some appear to have antler pick marks in roof (not from metal tools) but exact dating is speculation.
Chalk Wells are a much wider shaft, without any steps/scoops leading down to a bell shaped widening at the base. These are made much later and thought to all be after 1700 and the last known example was made between 1904-1908 in Kent. Entrance and exit was to be raised/lowered in a basket with rope. These were generally for extraction of chalk to burn for lime.
Based on this distinction the holes in Hangman's wood are Dene Holes, not Chalk Wells.
Diagram taken from subbrit (linked below)
What were the Dene holes for?
Cult of Mithras altars, smugglers' hoard, grain stores, royal gold mine, flint source (many don't have the right kind of flint, for flint use), hiding places, underground housing - all have been given as explanations and none seem very likely. The only plausible explanation is mining chalk for loaming nearby fields, as historically documented by Pliny the Elder. But never let common sense get in the way of a good story. Rather than some chalk mine I'm describing my exploration of "Cymbeline's Gold Mines", so much classier!
Diagrams, explanations and further reading on Dene holes see:
Deneholes | KURG
kurg.org.uk
Darenth Wood Dene Hole – Subterranea Britannica
Subterranea Britannica is a society devoted to the study and investigation of man-made (including Nuclear Bunkers) and man-used underground places.
www.subbrit.org.uk
Continued....
. Or maybe that's just the collapse process, not sure. Not so great either way
their is some cracking geology going on
