its squares, its dead ends, its arteries, and its circulation”
Les Miserables, Victor Hugo, 1862
For a discussion of the tectonic evolution of the Paris Basin, its Lutetian stratigraphy and the gypsum deposits of the Right Bank, please visit my previous post entitled "Geological Legacies of the Paris Basin: Part I - Plaster of Paris, the Windmills of Montmartre, the Park of Buttes-Chaumont and a New Artistic Creativity" here.
PARIS SOUTERRAIN - PARIS UNDERGROUND
Stroll the narrow cobbled streets and broad boulevards on the Left Bank of the old French capital. Enjoy Paris’s beautiful storefronts, its exquisite monuments, museums, parks and stunning architecture. Languish in a sidewalk café or dine in a fashionably chic bistro. For the casual observer, it’s impossible to imagine what lies underfoot – 20 to 25 meters below street level.
Paris is a city of layers – both above ground and below. Its underground has many new additions, while others are vestiges of the past, often lost and forgotten. Some are accessible to the public, and others have been sealed for an eternity.
There are Roman Empire foundations and more recent wartime shelters, medieval basements and mysterious church crypts, musty wine cellars and shadowy mushroom farms, subterranean shopping malls and modern multi-level car parks. Factor in 1,305 miles of storm drains and sewers, 133 miles of Métro and RER railway tunnels, and countless miles of utility lines and pipes for water, gas, electricity and telephone. Standing on the streets of Paris, you'd never suspect what exists below you unless you looked at a map of the underground that mirrors the landscape above.
|Modified from the Atlas du Paris Souterrain – a highly-recommended source of information!|
The city of Paris occupies a tiny portion of the extensive Paris Basin – a 140,000 square kilometer shallow epicontinental trough of flat valleys and low plateaus in the north of France. On a larger scale, the depocenter of the Anglo-Paris Basin that spans the English Channel into Great Britain resides on the continental shelf of the Eurasian plate. Its foundation is a Late Proterozoic Cadomian-late Paleozoic Variscan crystalline basement. Please visit my post Part I for the Paris Basin’s juicy tectonic details here.
|Paris (red dot) within the extensive Anglo-Paris Basin on a |
Jurassic through Neogene Surficial Geology Map
The basin’s strata were deposited in a multitude of Tertiary age transgressions and regressions of tropical seas that flooded the epicontinent of Western Europe. Formed in a mixed environment of marine, coastal, lagoonal and freshwater conditions, deposition was followed by compaction, cementation and eventual lithification.
|Modified from Ron Blakey and Colorado Plateau Geosystems, Inc.|
The sedimentary rocks that formed - during the Eocene epoch in particular - built the city of Paris: Bartonian age gypsums (gypse) for plaster of Paris on the Right Bank (north side of the river Seine) and Lutetian age limestones (calcaire grossier), chalks (craie) for lime-based cements and paints, clays (argile) for tiles and bricks, and sand (sable) for masonry on the Left Bank (south of the river). The deposits on each side of the river Seine are between two low plateaus, Montmartre and Montparnasse. Both banks were exploited from under the city, as Paris grew and expanded on the surface.
ANTICLINE OF MEUDON
Fortuitously for Paris’s architectural future, the axis of the Tertiary age anticline of Meudon (red dotted line below) passes south of the city. The flexure allowed for the excavation of Paris’s geological bounty of gypsum from the Right Bank and deeper, coarse limestone from the Left.
|Modified from M. Vire of MNHM and Jean-Pierre Gely, 2013|
The geologic transect (black line above) extends across the basin from north to south and is represented cross-sectionally below. Note the availability of Lutetian limestone (calcaire grossier) south of the Seine on the Left Bank and gypsum (gypse) north of the Seine on the Right Bank in Montmartre. The vertical scale across the basin is greatly exaggerated making Montmartre appear like the Matterhorn.
|Modified from M. Vire of MNHM and Jean-Pierre Gely, 2013|
TWO MAJOR EXPLOITATION ZONES OF PARIS
Thus, gypsum has been extracted in the hills of Paris on the Right Bank from Menilmontant, Montmartre and Buttes-Chaumont areas of the 18th, 19th and 20th arrondisements, respectively. Limestone was mined under the small Parisian hills of Montparnasse, Montsouris, Montrouge, the Butte aux Cailles and the Colline de Chaillot, largely on the Left Bank.
|Topographical Considerations of Paris|
Modified from Arch.ttu.edu
ANCIENNES CARRIÈRES DE PARIS - ANCIENT MINES OF PARIS
The areas of Right Bank gypsum (green clusters) and largely Left Bank limestone (red) exploitation can be seen highlighted on this old Paris map of 1908. The direction of flow of the River Seine is shown in black arrows.
By 53-52 BC, the Romans had conquered Gaul (roughly France and Belgium) and the Celtic Iron Age tribes living in the region. Within the Paris Basin, that included the Parisii, living on the banks of the river Seine. The Romans called their settlement on the hills south of the river Lutetia Parisiorum or Lutece in French. The name was derived from a Parisii word meaning marsh or swamp. In turn, geologists borrowed the name for the Lutetian age - a division of the Eocene epoch of the Cenozoic Era- the time in which the limestone called “Paris Stone” formed – 47.8 to 41.3 million years ago.
The Romans in the 1st century and the early Parisians through the end of the 12th century acquired coarse limestone for structures in the most instinctive of ways – from above ground where it was most convenient. It was removed from open quarries (carrières à ciel ouvert) where it had been exposed by erosion such as the region of the Seine’s ancestral tributary, the Bievre (see above). The technique was primitive, but the rock was readily available and had existing natural fractures that facilitated its extraction.
By the end of the 12th century, medieval Paris had become a medium-size, walled city with a population of 25,000 surrounded by countryside of farms and vineyards. The extraction of surface limestone was gradually replaced by underground workings to satisfy the sharply increased needs for building construction such as Notre-Dame Cathedral, the Louvre Palace and the ramparts of the city.
|Modified from M. Vire of MNHM and Jean-Pierre Gely, 2013|
The first mining method employed the “room and pillar” technique, called piliers tournes. After a horizontal tunnel was excavated, perpendicular and then parallel tunnels were added (right diagram). The result was a maze of interconnecting passageways with the weight of the ceiling supported by a grid of massive columns of untouched, solid limestone. It helped to prevent collapse of the undermined roof, but a significant portion of usable excavated material was lost.
|Modified from M. Vire of MNHM and Jean-Pierre Gely, 2013|
In the 16th century, the mining method of hagues et bourrages was employed that was economically productive and structurally sound. Instead of tunneling horizontally into the exploited table of limestone, miners would extract stone progressively outward from a central point. When the ceiling became sufficiently unsupported, a line of stacked piliers a bras was erected from the floor to the ceiling. When extraction continued outward, a second line of stone columns was added, which were then transformed into walls or hagues as the space in between was backfilled with waste rubble or bourrage.
The first underground limestone quarries were located in Paris's suburbs (faubourgs) on the Left Bank. As the city continued to grow, new underground quarries with interconnecting galleries were developed on the city’s expanding periphery. Old abandoned quarries fell into oblivion and were gradually built over.
|Formation and Evolution of Subsidence |
A fontis is a cavity that develops when the roof of a subterranean gallery caves in.
A cloche is the rounded top of the rubble pile.
Modified from Daniel Munier and from M. Vire
When the largest collapse occurred in 1774, a wave of panic spread through Paris. A giant sinkhole catastrophically swallowed a busy Parisian neighborhood including roads, buildings, houses, horses, carriages, oxcarts and throngs of people along Rue d’Enfer (now called Boulevard Saint Michel near Avenue Denfert-Rochereau). Appropriately, enfer is the French word for “hell,” and the gaping hole in the earth became known as the “mouth of hell.” The quarries that built the city of Paris were literally threatening to destroy it - neighborhood by neighborhood.
How ironic! The limestone that went into the construction of Notre-Dame, the Palais-Royal and the mansions of the Marais on the surface of Paris actually had come from the quarries beneath Rue d’Enfer – now taking revenge upon the city.
gypsum for plaster, limestone for walls, green clay for bricks and tiles.”
In response to the fear of collapse, King Louis XVI designated a commission to investigate the state of the Parisian underground on April 4, 1777. It was called the Inspection Unit for Quarries Below Paris and Surrounding Plains. The head of the newly minted office - appointed by the King by chance of fate only a few hours before the collapse - was an architect named Charles-Axel Guillaumot, who held the position of General Inspectorate of the Quarries (IGC) until his death in 1807 - in French, Inspection Générale des Carrières.
Author Graham Robb
In order to safeguard public roads and of course the King’s properties, Guillaumot erected pillars from the quarry floors to their ceilings, “retrospectively-created foundations for the edifices built on the surface” (Gilles Thomas). The result was that every undercut surface street was doubled by a gallery that followed the same layout. In a sense, Paris became a mirrored city with one above ground and the other below. This allowed the evolution of subsidence voids to be monitored and shored up as needed. The same can be said of the modern city of Paris with its underground double. Here's an example from the 13th arrondissemont.
It was necessary to render them accessible; to this effect,
a gallery wide enough to allow passage of construction materials was left under
and within the public way; at the gallery’s farthest point, another wall was built.
Perpendicular galleries were dug here and there to enable communication between
both sides of the public way and to allow movement from one gallery to the next.”
(Memoirs on the Work Ordered in Quarries in Paris and Adjacent Plains, 1804)
Another peril was threatening the city – an insidious one that had become equally intolerable and every bit as dangerous. Paris’s cemeteries had become horrifically overcrowded. The earliest burial grounds were on the southern out-skirts of the Roman-era city on the Left Bank - outside the city! By the 4th century, burials had moved to the Right Bank on filled-in marshland - within the city. In particular was the property of the Saints Innocents church in 1130 - named after the biblical narrative of the "Massacre of the Innocents" by Herod the Great, the Roman-appointed King of the Jews.
|Map of Paris in 1550|
The Cemetery of Saint-Innocents is circled for reference. Click for a larger view.
Modified from OldMapsofParis.com in the Public Domain
|Turgot-Berez Map Plan of Paris in 1739|
Modified from geographicus.com/blog/rare-and-antique-maps/antique-map-of-the-week-the-turgot-bretez-plan-of-paris
A close up of the charnel house shows the skulls stacked in the upper tiers, while rotting corpses literally littered the burying grounds. Now lost but recorded in manuscripts, a mural of Danse Macabre or the Dance of Death was painted on the south wall within an alcove of the charnel house. Represented in many languages and countries, the theme dates from 1424-24. No matter one’s station in life, the universality of death depicted in the “dance” is an artistic genre of late-medieval allegory. It was meant to remind people of life’s fragility and the vainness of the glories of their earthly lives. One might think that a view of the burial grounds was likely all that was needed!
for that precise reason, simple head and leg wounds become lethal in that hospital.
Nothing proves my point so well as the tally of patients who perish miserably each year
in the Paris Hôtel-Dieu…a fifth of the patients succumb; a frightful tally
treated only with the greatest indifference.”
Nothing was done to remedy the intolerable situation until King Louis XV initiated an investigation in 1763. His successor, King Louis XVI, in his first year on the throne in 1775, issued an edict to move the deceased out of the city. The church resisted the notion, which profited from burial fees. Business was good! To reduce the number of burials, the price was increased, something only the wealthy could afford.
Mine consolidations were still under way and included the addition of a network of interconnecting subterranean passageways for access. With the cemeteries closed, Police Prefect Lieutenant-General Alexandre Lenoir supported an idea of moving the dead to the newly renovated corridors to be used as an underground sepulcher. The idea became law in 1785. Saints-Innocents was to be evacuated and converted into the public square that has remained to this day, Place Joachim-du-Bellay – more on that story later in this post.
|The location of the Plains of Montrouge outside the walls of the city of Paris|
On April 7, 1786, the grounds of the former quarries of the Tombe-Issoire under the Plain of Montrouge (the burial site of a legendary giant named Issoire slain by William the monk) were sanctified in the presence of the church abbots, the architects of the project and Charles-Axel Guillaumot. On November 16th, Monseigneur Leclerc de Juigne and Archbishop of Paris ordered:
entailing the turning of the soil to a depth of five feet and the sieving of earth,
with any remaining corpses or bones to be transported and buried
in the new underground cemetery of the Montrouge Plain.”
Cited in Les Catacombes, etude historique, 1861
The first transfers of bones from Saints-Innocents to the Catacombs lasted 15 months and continued with the populations of Saint-Étienne-des-Grès, Saint-Eustache, Saint-Landry, Sainte-Croix-de-la-Bretonneries, Saint-Julien-des-Ménétriers and so forth. Continuing to 1814, every cemetery, church ground, crypt and tomb of Paris was nocturnally emptied of its human remains. In total, over six million Parisians were withdrawn and transported to their new “haven of peace” beneath the Plains of Montrouge. The exact number is impossible to determine. The estimate is based on the number of burials up to the year 1860 when the contents of the last graves were transferred to the ossuary.
The Catacombs of Paris lie some 20 meters beneath the south Paris suburb of Montrouge. The town bears little resemblance to the former bucolic royal hunting ground on the Plain of Montrouge. In fact, one must look hard to identify buildings of “old” pre-Haussmann Paris, but they’re there. In fact, you arrive beneath one if you take the Paris Métro at Denfert-Rochereau station, and you must enter one in order to descend into the Catacombs!
|View of Barriere d'Enfer along the Wall of the Farmers-General. Note the nearby location of the Lion of Belfort and to the west, the Cemetery of Montparnesse.|
Modified from OldMapsofParis.com.
Immediately south of the square is the Barrière d’Enfer – the gate built along the Wall of the Farmers-General around the city. Fermiers-Généraux or tax farmers collected octroi at the tollhouses, an unpopular (and highly abused) tax on goods both entering and leaving the city. The two tollhouses on the long-gone wall still remain - four of 62 surviving ones that punctuated the wall built between 1784 and 1791. Actually several walls surrounded Paris between the early Middle Ages to the mid-19th century, the others being for defense rather than tax collection.
And to shorten our horizon
The Farm judges it necessary
To put Paris in prison”
During the 1830’s to 1840’s, excursions were not limited to just the Ossuary and led by mine overseers “who guided them as struck their fancy; inevitable abuses occurred, the quarry galleries as well as the ossuary were damaged by unscrupulous people and visitor lost their way.” (Emile Gerards in Paris Souterrain, 1991).
We arrived at the east pavilion of the Catacombs well before the opening time of 10 AM and found a line already forming at the entrance. Both Parisians and tourists alike want to be amongst the first 200 visitors allowed in, and we were no exception.
|La Visite aux Catacombes, Aquarelle, 1804-1814, Musee Carnavalet|
|Visite aux Catacombes|
Reproduction d'une gravure anglaise, 1822, Carte postale, vers 1900, Collection Roger-Viollet
|Corridor leading to the Ossuary portion of the Catacombs|
LE BAIN DE PIEDS DES CARRIERS - THE QUARRYMEN'S FOOTBATH
Limestone is more or less finely porous and permeable to water. At depth - from a few centimeters to several hundred meters - and depending on the series of geological strata and the relief, the rocks are saturated with water. This forms a series of superimposed phreatic zones or aquifers, separated by impermeable argillaceous (clayey) rocks. The water table represents the first phreatic zone to be reached when a well is dug such as the Quarryman's Footbath. Its surface fluctuates with the whim of the rain or even the nearest river. By the way, the principle of artesian wells was demonstrated in 1828 by Héricart de Thury and later applied in the drilling of the Grenelle well in the 15th arrondissement of Paris.
|Bains de Pieds des Carrieres, Catacombs Brochure, DAC/Ch. Fouin|
THE EMPIRE OF DEATH
You’ve officially entered the Municipal Ossuary having passed beneath the engraved, limestone lintel that declares “Stop! This is the empire of death”. Of course, tens of thousands of visitors every year are hardly dissuaded by the ominous warning. In actuality, this is the “new” entrance, the original being at the end of the ossuary. Visits to the ossuary begin with the most recent bone transfers.
The limestone quarries have been closed to the public since 1955, but the Catacombs have remained open. At the time that Guillaumot was strengthening the tunnels beneath Paris, King Louis was closing the overcrowded cemeteries. The exhumations went on for years - long after the King lost his head in the French Revelation in 1793 - until all the bodies had been reinterred in a new realm – this, the Empire of the Dead.
The black tar line on the ceiling was traced as a path to follow by candlelight to prevent 19th century visitors from losing their way in the maze of galleries. An example of how easy it is to get lost is told by the tale of the porter Philibert Aspairta, who entered the quarry alone in 1793 and lost his way. He was found by a survey crew 11 years later and given a proper burial where he had been discovered.
In the words of L.F. Hivert in 1860:
Immediately within the entrance to the ossuary is a stele (funerary monument) dated 1810 that commemorates the establishment of the Catacombs. It was moved from the original entrance when the ossuary was expanded.
|Tiny stalactites forming on the ceiling of the Catacombs|
Rather than cover the walls with hand-stacked masonry-retainers, some subsidence structures were simply consolidated with sprayed cement. The fontis seen below was reinforced with an arch, whereas others were reinforced with an internal shell of masonry. The stratigraphic layers can be viewed in cross section as if seen from within a bell. The colored lines were added to help delineate the strata – an embellishment that I could do without.
In all, it’s a quite remarkable catastrophic collapse-structure that can be viewed from within and an incredible display of quarry history. One must remember that these very subsidence bells threaten the lives of Parisians on the surface, although most everyone goes about their daily lives with total nonchalance.
|Cloche de fontis aux Catacombes|
|Plaster cast of Campanile giganteum, an exceptionally large marine gastropod from the Eocene epoch of the Paris Basin, was on display within the Catacombs|
|Nummulites laevigatus, a foraminifera that left a fossilized shell that looked like a "liard" (a small Medieval coin) formed a meter-thick layer called pierre a liards or liard stones.|
|Cuvier's and Brongniart's joint venture in delineating the stratigraphy of Paris in 1832|
|Our catacombic, underground journey began at the Barriere Denfert-Rochereau (upper arrow) |
and followed a winding path to 36 Rue Rémy-Dumoncel (bottom arrow).
As if 6 million skeletons wasn't enough, a subtle reminder of the tenuous grip on life that we all possess rests strategically on the wall immediately at the top of the arduous stair-climb to the street.
It's been over 225 years since the King's edict to close the Cemetery of Saint-Innocents was issued. Since then, much of Paris's landscape has changed, most notably during the radical urbanization program of Napoléon III and his Prefect of the Seine Georges Eugene Haussmann in the 19th century. The limestone quarries and the overcrowded, center-city cemeteries have closed, and their bones have been moved to the Municipal Ossuaries called the Catacombs.
|The square and market of Place Joachim de Bellay with the Fountain of Innocents in 1850|
Theodor Josef Hubert Hoffbauer (1839-1922), Public Domain.
|Modified from Wikipedia|
|The Fountain of the Innocents within Place Joachim de Bellay|
Photograph by Janet Penn. www.janetpennphotography.
|A "freely-flowing" Bievre River in the 5th arrondissement c. 1862 taken by the government commissioned photographer Charles Marville |
Wikipedia and the Museum of Art, The Horace W. Goldsmith Foundation Fund
|From National Geographic|
|Set of Phase Screens of Paris|
The various colors represent levels of deformation.
Atlas du Paris Souterrain under the direction of Alain Clement and Gilles Thomas, 2001. A fantastic, thorough and entertaining presentation in French with wonderful photographs.
Paris Souterrain by Emmanuel Gaffard, 2007.
The Catacombs of Paris by Gilles Thomas, 2011. Another thorough presentation.