Monk's Mound
Encyclopedia
Monks Mound is the largest Pre-Columbian
earthwork
in America north of Mesoamerica
. Located at the Cahokia Mounds UNESCO World Heritage Site near Collinsville, Illinois
, its size was calculated in 1988 as about 100 feet (30 m) high, 955 feet (291 m) long including the access ramp at the southern end, and 775 feet (236 m) wide. This makes Monks Mound roughly the same size at its base as the Great Pyramid of Giza
(13.1 acres / 5.3 hectares). Its base circumference is larger than the Pyramid of the Sun
at Teotihuacan
.
Unlike Egyptian pyramids which were built of stone, the platform mound
was constructed almost entirely of layers of basket-transported soil and clay. Because of this construction and its flattened top, over the years, it has retained rainwater within the structure. This has caused "slumping", the avalanche-like sliding of large sections of the sides at the highest part of the mound. Its designed dimensions would have been significantly smaller than its present extent, but recent excavations have revealed that slumping was a problem even while the mound was being made.
Construction of Monks Mound by the Mississippian culture
began about 900–950 CE, on a site which had already been occupied by buildings. The original concept seems to have been a much smaller mound
, now buried deep within the northern end of the present structure. At the northern end of the summit plateau, as finally completed around 1100 CE, is an area raised slightly higher still, on which was placed a building over 100 feet (30 m) long, the largest in the entire Cahokia Mounds urban zone. Deep excavations in 2007 confirmed findings from earlier test borings, that several types of earth and clay
from different sources had been used successively. Study of various sites suggests that the stability of the mound was improved by the incorporation of bulwarks, some made of clay, others of sods from the Mississippi flood-plain, which permitted steeper slopes than the use of earth alone.
The most recent section of the mound, added some time before 1200 CE, is the lower terrace at the south end, which was added after the northern end had reached its full height. It may partly have been intended to help minimize the slumping which by then was already under way. Today, the western half of the summit plateau is significantly lower than the eastern; this is the result of massive slumping, beginning about 1200 CE. This also caused the west end of the big building to collapse. It may have led to the abandonment of the mound's high status, following which various wooden buildings were erected on the south terrace, and garbage was dumped at the foot of the mound. By about 1300, the urban society at Cahokia Mounds was in serious decline. When the eastern side of the mound started to suffer serious slumping, it was not repaired.
missionaries built a chapel at the west end of the south terrace of the mound. The River L'Abbe Mission served a small Illiniwek
community, until they were forced to abandon the area by rival tribes about 1752. In 1776, during the American Revolutionary War
, a trading post
called the Cantine was established next to the mound (by then known as the Great Nobb). It lasted only until 1784.
In the early nineteenth century, the land was claimed by people of French descent, and Nicholas Jarrot had a deed for most of it. He donated some to a small group of French Trappist
monks, who settled on one of the smaller mounds from 1809. They took advantage of the big mound's terraces to grow produce, which was elevated above the danger of flooding: wheat on the upper levels, garden produce on the south terrace. During their short stay in the area, which lasted until 1813, Henry Brackenridge visited the site and published the first detailed description of the largest mound. He named it Monks Mound.
In 1831 T. Amos Hill bought the plot including the Mound. He built a house on the upper terrace, and sank a well. This work revealed various archaeological remains, including human bones.
Many archaeological investigations of the mound have taken place since then. One of the biggest began in the 1960s, when Nelson Reed, a local businessman and historian of native cultures, obtained permission to conduct excavations. He was trying to locate the high-status building (temple or palace) presumed to have stood at the peak of Monk's Mound. By drilling cores at various points on the mound, his team revealed the various stages of its construction from the 10th to 12th centuries CE. Remains of a fairly recent house (presumably Hill's) were found, but no temple.
In 1970 Reed returned to work at the mound, and adopted a new strategy: scraping away the topsoil from several 5-metre-square patches with a backhoe
, to a depth of around 60cm. This quickly revealed various features, including what appeared to be the outline of the temple. Further backhoe work in 1971 confirmed the shape of the presumed temple (at over 30 metres long, the largest building found at Cahokia). This technique was opposed by professional archaeologists because it destroyed several hundred years of stratification
over most of the mound's summit, which was the evidence by which they could place and evaluate artifacts and construction. Reed's backhoe excavations revealed other significant features, such as a hole which seemed to have been the socket for a post about three feet (one metre) in diameter. The dramatic finds encouraged the Governor of Illinois to budget for an expansion of the Cahokia Mounds State Park.
The repairs of the 1980s and 1990s were only partly successful. In 2004-5 more serious slumping episodes occurred. These demonstrated that adding new earth to repair the major slump on the east side had been a mistake. Experts decided to take a new approach. In 2007, backhoes were used to dig out the entire mass of earth from this slump and another at the northwest corner, to a level beyond the internal slippage zone. Engineers created a series of anti-slip "steps" across the exposed face before the original earth (minus the imported repair material) was replaced at its original level. To avoid introducing water deep into the mound's interior, the work was carried out in high summer, and as quickly as possible. In parallel with the repair work, teams of archaeologists studied the evidence that was being revealed. The eastern sliding zone penetrated more deeply within the mound than originally estimated, and the excavation had to be very large- 50 feet (15 m) wide, to a height of 65 feet (20 m) above the mound base. This heightened concerns about a conflict between conservation and archaeology.
Pre-Columbian
The pre-Columbian era incorporates all period subdivisions in the history and prehistory of the Americas before the appearance of significant European influences on the American continents, spanning the time of the original settlement in the Upper Paleolithic period to European colonization during...
earthwork
Earthworks (archaeology)
In archaeology, earthwork is a general term to describe artificial changes in land level. Earthworks are often known colloquially as 'lumps and bumps'. Earthworks can themselves be archaeological features or they can show features beneath the surface...
in America north of Mesoamerica
Mesoamerica
Mesoamerica is a region and culture area in the Americas, extending approximately from central Mexico to Belize, Guatemala, El Salvador, Honduras, Nicaragua, and Costa Rica, within which a number of pre-Columbian societies flourished before the Spanish colonization of the Americas in the 15th and...
. Located at the Cahokia Mounds UNESCO World Heritage Site near Collinsville, Illinois
Collinsville, Illinois
Collinsville is a city located mainly in Madison County, and partially in St. Clair County, both in Illinois. As of the 2010 census, the city had a population of 26,016. Collinsville is approximately 12 miles from St. Louis, Missouri and is considered part of that city's Metro-East area...
, its size was calculated in 1988 as about 100 feet (30 m) high, 955 feet (291 m) long including the access ramp at the southern end, and 775 feet (236 m) wide. This makes Monks Mound roughly the same size at its base as the Great Pyramid of Giza
Great Pyramid of Giza
The Great Pyramid of Giza is the oldest and largest of the three pyramids in the Giza Necropolis bordering what is now El Giza, Egypt. It is the oldest of the Seven Wonders of the Ancient World, and the only one to remain largely intact...
(13.1 acres / 5.3 hectares). Its base circumference is larger than the Pyramid of the Sun
Pyramid of the Sun
The Pyramid of the Sun is the largest building in Teotihuacan and one of the largest in Mesoamerica. Found along the Avenue of the Dead, in between the Pyramid of the Moon and the Ciudadela, and in the shadow of the massive mountain Cerro Gordo, the pyramid is part of a large complex in the heart...
at Teotihuacan
Teotihuacan
Teotihuacan – also written Teotihuacán, with a Spanish orthographic accent on the last syllable – is an enormous archaeological site in the Basin of Mexico, just 30 miles northeast of Mexico City, containing some of the largest pyramidal structures built in the pre-Columbian Americas...
.
Unlike Egyptian pyramids which were built of stone, the platform mound
Platform mound
A platform mound is any earthwork or mound intended to support a structure or activity.-Eastern North America:The indigenous peoples of North America built substructure mounds for well over a thousand years starting in the Archaic period and continuing through the Woodland period...
was constructed almost entirely of layers of basket-transported soil and clay. Because of this construction and its flattened top, over the years, it has retained rainwater within the structure. This has caused "slumping", the avalanche-like sliding of large sections of the sides at the highest part of the mound. Its designed dimensions would have been significantly smaller than its present extent, but recent excavations have revealed that slumping was a problem even while the mound was being made.
Construction and abandonment
Mississippian culture
The Mississippian culture was a mound-building Native American culture that flourished in what is now the Midwestern, Eastern, and Southeastern United States from approximately 800 CE to 1500 CE, varying regionally....
began about 900–950 CE, on a site which had already been occupied by buildings. The original concept seems to have been a much smaller mound
Platform mound
A platform mound is any earthwork or mound intended to support a structure or activity.-Eastern North America:The indigenous peoples of North America built substructure mounds for well over a thousand years starting in the Archaic period and continuing through the Woodland period...
, now buried deep within the northern end of the present structure. At the northern end of the summit plateau, as finally completed around 1100 CE, is an area raised slightly higher still, on which was placed a building over 100 feet (30 m) long, the largest in the entire Cahokia Mounds urban zone. Deep excavations in 2007 confirmed findings from earlier test borings, that several types of earth and clay
Clay
Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...
from different sources had been used successively. Study of various sites suggests that the stability of the mound was improved by the incorporation of bulwarks, some made of clay, others of sods from the Mississippi flood-plain, which permitted steeper slopes than the use of earth alone.
The most recent section of the mound, added some time before 1200 CE, is the lower terrace at the south end, which was added after the northern end had reached its full height. It may partly have been intended to help minimize the slumping which by then was already under way. Today, the western half of the summit plateau is significantly lower than the eastern; this is the result of massive slumping, beginning about 1200 CE. This also caused the west end of the big building to collapse. It may have led to the abandonment of the mound's high status, following which various wooden buildings were erected on the south terrace, and garbage was dumped at the foot of the mound. By about 1300, the urban society at Cahokia Mounds was in serious decline. When the eastern side of the mound started to suffer serious slumping, it was not repaired.
European settlers
There is no evidence of significant Native American settlement in the Cahokia Mounds urban area for hundreds of years after about 1400 CE. In 1735 FrenchFrench people
The French are a nation that share a common French culture and speak the French language as a mother tongue. Historically, the French population are descended from peoples of Celtic, Latin and Germanic origin, and are today a mixture of several ethnic groups...
missionaries built a chapel at the west end of the south terrace of the mound. The River L'Abbe Mission served a small Illiniwek
Illiniwek
The Illinois Confederation, sometimes referred to as the Illiniwek or Illini, were a group of twelve to thirteen Native American tribes in the upper Mississippi River valley of North America...
community, until they were forced to abandon the area by rival tribes about 1752. In 1776, during the American Revolutionary War
American Revolutionary War
The American Revolutionary War , the American War of Independence, or simply the Revolutionary War, began as a war between the Kingdom of Great Britain and thirteen British colonies in North America, and ended in a global war between several European great powers.The war was the result of the...
, a trading post
Trading post
A trading post was a place or establishment in historic Northern America where the trading of goods took place. The preferred travel route to a trading post or between trading posts, was known as a trade route....
called the Cantine was established next to the mound (by then known as the Great Nobb). It lasted only until 1784.
In the early nineteenth century, the land was claimed by people of French descent, and Nicholas Jarrot had a deed for most of it. He donated some to a small group of French Trappist
TRAPPIST
TRAPPIST is Belgian robotic telescope in Chile which came online in 2010, and is an acronym for TRAnsiting Planets and PlanetesImals Small Telescope, so named in homage to Trappist beer produced in the Belgian region. Situated high in the Chilean mountains at La Silla Observatory, it is actually...
monks, who settled on one of the smaller mounds from 1809. They took advantage of the big mound's terraces to grow produce, which was elevated above the danger of flooding: wheat on the upper levels, garden produce on the south terrace. During their short stay in the area, which lasted until 1813, Henry Brackenridge visited the site and published the first detailed description of the largest mound. He named it Monks Mound.
In 1831 T. Amos Hill bought the plot including the Mound. He built a house on the upper terrace, and sank a well. This work revealed various archaeological remains, including human bones.
Archaeology
Thomas I. Ramey, who bought the site in 1864, began an era of more responsible ownership, and encouraged archaeological investigation. Many artifacts were found at or near the surface. Ramey had a tunnel made nearly 30 metres into the north face of the mound, but it revealed nothing of historic interest. By this time, people were beginning to consider the mound more within its context. A survey made for local dentist Dr. John R. Patrick in the 1880s marked the beginning of modern understanding of the Cahokia site as a whole, and its relationship to other sites in the area.Many archaeological investigations of the mound have taken place since then. One of the biggest began in the 1960s, when Nelson Reed, a local businessman and historian of native cultures, obtained permission to conduct excavations. He was trying to locate the high-status building (temple or palace) presumed to have stood at the peak of Monk's Mound. By drilling cores at various points on the mound, his team revealed the various stages of its construction from the 10th to 12th centuries CE. Remains of a fairly recent house (presumably Hill's) were found, but no temple.
In 1970 Reed returned to work at the mound, and adopted a new strategy: scraping away the topsoil from several 5-metre-square patches with a backhoe
Backhoe
A backhoe, also called a rear actor or back actor, is a piece of excavating equipment or digger consisting of a digging bucket on the end of a two-part articulated arm. They are typically mounted on the back of a tractor or front loader...
, to a depth of around 60cm. This quickly revealed various features, including what appeared to be the outline of the temple. Further backhoe work in 1971 confirmed the shape of the presumed temple (at over 30 metres long, the largest building found at Cahokia). This technique was opposed by professional archaeologists because it destroyed several hundred years of stratification
Stratification (archeology)
Stratification is a paramount and base concept in archaeology, especially in the course of excavation. It is largely based on the Law of Superposition...
over most of the mound's summit, which was the evidence by which they could place and evaluate artifacts and construction. Reed's backhoe excavations revealed other significant features, such as a hole which seemed to have been the socket for a post about three feet (one metre) in diameter. The dramatic finds encouraged the Governor of Illinois to budget for an expansion of the Cahokia Mounds State Park.
Preservation
From the time the original urban society collapsed, the great mound became overgrown with trees, the roots of which helped stabilize its steep slopes. In the 20th century, researchers removed the trees in the course of work at the mound and park preparation. Reduction of groundwater levels in the Mississippi floodplain during the 1950s caused the mound to dry out, damaging the clay layers within. When heavy rainfall occurred, it caused new slumping, starting about 1956. The increasingly violent weather of recent decades has exacerbated the problem. In 1984-5 there were several slumps, and the state government brought in surplus soil to make repairs to the major scar on the eastern side. A decade later, there was further slumping on the western side, so irregular that repair was impractical. Drains were installed to reduce the effects of heavy rain. It was during this process that workers discovered a mass of stone deep within the mound.The repairs of the 1980s and 1990s were only partly successful. In 2004-5 more serious slumping episodes occurred. These demonstrated that adding new earth to repair the major slump on the east side had been a mistake. Experts decided to take a new approach. In 2007, backhoes were used to dig out the entire mass of earth from this slump and another at the northwest corner, to a level beyond the internal slippage zone. Engineers created a series of anti-slip "steps" across the exposed face before the original earth (minus the imported repair material) was replaced at its original level. To avoid introducing water deep into the mound's interior, the work was carried out in high summer, and as quickly as possible. In parallel with the repair work, teams of archaeologists studied the evidence that was being revealed. The eastern sliding zone penetrated more deeply within the mound than originally estimated, and the excavation had to be very large- 50 feet (15 m) wide, to a height of 65 feet (20 m) above the mound base. This heightened concerns about a conflict between conservation and archaeology.
General reading
- Price, Douglas T. and Gary M. Feinman. Images of the Past, 5th ed. New York: McGraw-Hill (2008) ISBN 9780073405209. pp. 282-285.
See also
- CahokiaCahokiaCahokia Mounds State Historic Site is the area of an ancient indigenous city located in the American Bottom floodplain, between East Saint Louis and Collinsville in south-western Illinois, across the Mississippi River from St. Louis, Missouri. The site included 120 human-built earthwork mounds...
- Sugarloaf MoundSugarloaf MoundSugarloaf Mound is the sole remaining Mississippian culture platform mound in St. Louis, Missouri. The mound covers three city blocks, measures approximately in height, north/south and east/west. It is located on the former border between St. Louis and the autonomous city of Carondelet. In 1809...
- Southeastern Ceremonial ComplexSoutheastern Ceremonial ComplexThe Southeastern Ceremonial Complex is the name given to the regional stylistic similarity of artifacts, iconography, ceremonies, and mythology of the Mississippian culture that coincided with their adoption of maize agriculture and chiefdom-level complex social organization from...
- Mississippian cultureMississippian cultureThe Mississippian culture was a mound-building Native American culture that flourished in what is now the Midwestern, Eastern, and Southeastern United States from approximately 800 CE to 1500 CE, varying regionally....
- List of Mississippian sites