Midden: An Archaeological Garbage Dump

A midden (or kitchen midden) is the archaeological term for trash or garbage heap. Middens are a type of archaeological feature, consisting of localized patches of dark-colored earth and concentrated artifacts which resulted from the deliberate discard of refuse, food remains, and domestic materials such as broken and exhausted tools and crockery. Middens are found everywhere humans live or have lived, and archaeologists love them.

The name kitchen midden comes from the Danish word køkkenmødding (kitchen mound), which originally referred specifically to coastal Mesolithic shell mounds in Denmark. Shell middens, primarily made up of the shells of mollusks, were one of the first types of non-architectural features investigated in pioneering 19th-century archaeology. The name "midden" stuck for these hugely informative deposits, and it is now used globally to refer to all kinds of trash heaps.

How a Midden Forms

Middens had multiple purposes in the past and still do. At their most basic, middens are places where rubbish is placed, out of the way of normal traffic, out of the way of normal sight and smell. But they are also storage facilities for recyclable objects; they can be used for human burials; they can be used for building material; they can be used to feed animals, and they can be the focus of ritual behaviors. Some organic middens act as compost heaps, that improve the soil of an area. A study of Chesapeake Bay shell middens on the Atlantic coast of the United States by Susan Cook-Patton and colleagues found the presence of middens significantly enhanced local soil nutrients, especially nitrogen, calcium, potassium, and manganese, and to have increased soil alkalinity. These positive improvements have lasted for at least 3,000 years.

Middens can be created at the household level, shared within a neighborhood or community, or even associated with a specific event, such as a feast. Middens have different shapes and sizes. The size reflects how long a particular midden was used, and what percentage of material stored in it is organic and decays, as opposed to non-organic material which does not. In historic farmsteads midden deposits are found in thin layers called "sheet middens", the result of the farmer throwing out scraps for the chickens or other farm animals to pick over.

But they can also be enormous. Modern middens are known as "landfills," and in many places today, there are groups of scavengers who mine the landfills for recyclable goods (see Martinez 2010).

What's to Love about a Midden

Archaeologists love middens because they contain the broken remains from all kinds of cultural behaviors. Middens hold food remains—including pollen and phytoliths as well as the food themselves—and pottery or pans that contained them. They include exhausted stone and metal tools; organic matter including charcoal suitable for radiocarbon dating; and sometimes burials and evidence of ritual behaviors. Ethnoarchaeologist Ian McNiven (2013) found that Torres Islanders had distinctly separate midden areas set aside from feasts, and used them as a reference point to tell stories about past parties they recalled. In some cases, midden environments allow for excellent preservation of organic materials such as wood, basketry, and plant food.

A midden can allow the archaeologist to reconstruct past human behaviors, things such as relative status and wealth and subsistence behaviors. What a person throws away is a reflection of both what they eat and what they won't eat. Louisa Daggers and colleagues (2018) are only the latest in a long line of researchers that use middens to identify and study the effects of climate change.

Types of Studies

Middens sometimes are a source of indirect evidence for other forms of behavior. For example, archaeologists Todd Braje and Jon Erlandson (2007) compared abalone middens in the Channel Islands, comparing one for black abalone, collected by historic period Chinese fishermen, and one for red abalone collected 6,400 years ago by Archaic period Chumash fishermen. The comparison highlighted different purposes for the same behavior: The Chumash were specifically harvesting and processing a wide range of edible foods, focused on the abalone; while the Chinese were solely interested in the abalone.

Another Channel Island study led by archaeologist Amira Ainis (2014) looked for evidence of the use of sea kelp. Seaweeds such as kelp were extremely useful to prehistoric people, used to make cordage, nets, mats, and basketry, as well as edible wrappings for steaming food—in fact, they are the basis of the Kelp Highway Hypothesis, thought to have been a major food source for the first colonists of the Americas. Unfortunately, kelp doesn't preserve well. These researchers found tiny gastropods in the midden that are known to live on kelp and used those to bolster their argument that the kelp was being harvested.

Paleo-Eskimo in Greenland, Late Stone South Africa, Catalhoyuk

A Paleo-Eskimo midden at the Qajaa site in western Greenland was preserved by permafrost. Studies of that midden by archaeologist Bo Elberling and colleagues (2011) revealed that in terms of thermal properties such as heat generation, oxygen consumption, and carbon monoxide production, the Qajaa kitchen midden produced four to seven times more heat than natural sediment in a peat bog.

Many studies have been conducted on the Late Stone Age shell middens on the coast of South Africa, so-called megamiddens. Smauli Helama and Bryan Hood (2011) looked at mollusks and corals as if they were tree rings, using variations in the growth rings to yield the rates of midden accumulation. Archaeologist Antonieta Jerardino (2017, among others) has looked at micro paleoenvironments in the shell middens, to identify sea-level changes.

At the Neolithic village of Çatalhöyük in Turkey, Lisa-Marie Shillito and colleagues (2011, 2013) used microstratigraphy (the detailed examination of the layers in a midden) to identify fine layers interpreted as hearth rake and floor-sweeping; seasonal indicators such as seeds and fruits, and in situ burning events associated with pottery production.

Significance of Middens

Middens are enormously important to archaeologists, both as one of the earliest features that fired up their interest, and as a seemingly never-ending source of information about human diet, ranking, social organization, environment, and climate change. What we do with our trash, whether we hide it and try to forget about it, or use it to store recyclables or the bodies of our loved ones, it is still with us and still reflects our society.

Sources

• Ainis, Amira F., et al. "Using Non-Dietary Gastropods in Coastal Shell Middens to Infer Kelp and Seagrass Harvesting and Paleoenvironmental Conditions." Journal of Archaeological Science 49 (2014): 343–60. Print.
• Arias, Pablo, et al. "Looking for the Traces of the Last Hunter–Gatherers: Geophysical Survey in the Mesolithic Shell Middens of the Sado Valley (Southern Portugal)." Quaternary International 435 (2017): 61–70. Print.
• Braje, Todd J., and Jon M. Erlandson. "Measuring Subsistence Specialization: Comparing Historic and Prehistoric Abalone Middens on San Miguel Island, California." Journal of Anthropological Archaeology 26.3 (2007): 474–85. Print.
• Cook-Patton, Susan C., et al. "Ancient Experiments: Forest Biodiversity and Soil Nutrients Enhanced by Native American Middens." Landscape Ecology 29.6 (2014): 979–87. Print.
• Daggers, Louisa, et al. "Assessing the Early Holocene Environment of Northwestern Guyana: An Isotopic Analysis of Human and Faunal Remains." Latin American Antiquity 29.2 (2018): 279–92. Print.
• Elberling, Bo, et al. "Paleo-Eskimo Kitchen Midden Preservation in Permafrost under Future Climate Conditions at Qajaa, West Greenland." Journal of Archaeological Science 38.6 (2011): 1331–39. Print.
• Gao, X., et al. "Organic Geochemical Approaches to Identifying Formation Processes for Middens and Charcoal-Rich Features." Organic Geochemistry 94 (2016): 1–11. Print.
• Helama, Samuli, and Bryan C. Hood. "Stone Age Midden Deposition Assessed by Bivalve Sclerochronology and Radiocarbon Wiggle-Matching of Arctica Islandica Shell Increments." Journal of Archaeological Science 38.2 (2011): 452–60. Print.
• Jerardino, Antonieta. "Water-Worn Shell and Pebbles in Shell Middens as Proxies of Palaeoenvironmental Reconstruction, Shellfish Procurement and Their Transport: A Case Study from the West Coast of South Africa." Quaternary International 427 (2017): 103–14. Print.
• Koppel, Brent, et al. "Isolating Downward Displacement: The Solutions and Challenges of Amino Acid Racemisation in Shell Midden Archaeology." Quaternary International 427 (2017): 21–30. Print.
• ---. "Untangling Time-Averaging in Shell Middens: Defining Temporal Units Using Amino Acid Racemisation." Journal of Archaeological Science: Reports 7 (2016): 741–50. Print.
• Latorre, Claudio, et al. "Using Archaeological Shell Middens as a Proxy for Past Local Coastal Upwelling in Northern Chile." Quaternary International 427 (2017): 128–36. Print.
• Martinez, Candace A. "Informal Waste-Pickers in Latin America: Sustainable and Equitable Solutions in the Dumps." Global Sustainability as a Business Imperative. Eds. Stoner, James A. F. and Charles Wankel. New York: Palgrave Macmillan US, 2010. 199–217. Print.
• McNiven, Ian J. "Ritualized Middening Practices." Journal of Archaeological Method and Theory 20.4 (2013): 552–87. Print.
• Shillito, Lisa-Marie, and Wendy Matthews. "Geoarchaeological Investigations of Midden-Formation Processes in the Early to Late Ceramic Neolithic Levels at Çatalhöyük, Turkey Ca. 8550–8370 Cal Bp." Geoarchaeology 28.1 (2013): 25–49. Print.
• Shillito, Lisa-Marie, et al. "The Microstratigraphy of Middens: Capturing Daily Routine in Rubbish at Neolithic Çatalhöyük, Turkey." Antiquity 85.329 (2011): 1027–38. Print.