Hubbry Logo
Kalambo structureKalambo structureMain
Open search
Kalambo structure
Community hub
Kalambo structure
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Kalambo structure
Kalambo structure
Kalambo structure
View on Wikipedia
from Wikipedia

The Kalambo structure is a Lower Palaeolithic wooden structure, of which two pieces have been uncovered along with other wooden tools. Discovered at the site of Kalambo Falls, Zambia, it is currently the oldest known wooden structure,[1] determined through luminescence dating to be at least 476,000 years old,[1] predating Homo sapiens.[1][2][3]

Key Information

History of discovery

[edit]

Excavations at Kalambo Falls in the 1950s and 1960s recovered wooden artifacts of possible hominin origin, although wear and other taphonomic processes prevented scientists from ascertaining the origin of the artifacts with certainty.[2] The area contains the Kalambo Falls Prehistoric Site.

The structure and accompanying tools were recovered in 2019 at Site BLB around the Kalambo River.[1]: 108  The structure itself was found in area BLB5, located below the river, in association with Acheulean artifacts. The discovery was considered unusual because wood does not usually survive for so long. Geoff Duller, who was part of the team that made the discovery in 2019, said high water levels and fine sediment encasing the structure helped to preserve the wood.[1][4]

Description

[edit]

The structure consists of two interlocking wooden logs of large-fruited bushwillow (Combretum zeyheri), connected by a notch securing one perpendicular to the other. The smaller log, measuring 141.3 cm (55.6 in) in length, has tapered ends as well as a U-shaped notch and overlies the larger log, which passes through the notch.[1] According to Duller, the structure probably would have been part of a wooden platform used as a walkway, to keep food or firewood dry, or perhaps as a base on which to build a dwelling. The discovery could indicate that the hominins who lived at Kalambo Falls may have had a settled lifestyle, which could challenge the prevailing view that Stone Age hominins had a nomadic lifestyle.[4]

The notch in the upper log shows evidence of having been made through scraping and adzing, with fire use also hinted at by infrared spectroscopy. The underlying trunk shows evidence of striations with V-shaped cutmarks, both at its midpoint and along the narrowed end going through the notch, also indicative of possible scraping.[1]

Using luminescence dating, the logs were dated to 476±23 kya. Carbon dating confirmed their non-intrusive nature, reporting an age higher than the maximum range of 50 kya.

Another wooden log, showing tapered ends and a similar notch, had previously been described in Site B of Kalambo Falls, also from the Acheulean, although not conclusively identified as part of a hominid-made structure at the time.[5]

The wooden tools found along with the structure include a wedge and a digging stick. They have been found in several areas across the BLB site, and are younger than the structure itself, having been dated to between 390,000 and 324,000 years ago.[1]

Implications

[edit]

Archaeologists such as Larry Barham of the University of Liverpool, the leader of the expedition that uncovered the structure, believe that wooden tools were potentially even more common than stone tools in the Stone Age, although due to rapid decay of wood in soil, archaeologists could not find such tools.[2] Mentioning the likely co-evolution of wooden and stone tools, they link the innovation shown by the Kalambo structure to the later invention of hafting, with several parts linked together in a single tool.[1]

The timing of the construction of the Kalambo structure coincides with a period of forest coverage of the Kalambo River basin. Barham's team believes the high resource availability of the environment, a permanently elevated water table, and the improvement brought by constructing elevated structures above the floodplain created a habitat conducive to sustained occupation.[1]

The discovery predates the earliest known appearance of Homo sapiens by more than 100,000 years. As no hominin remains have been discovered at Kalambo Falls, no conclusive attribution has been made, although a 300,000-year-old Homo heidelbergensis skull has been found at another Zambian site.[2]

References

[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Kalambo structure

View on Grokipedia
from Grokipedia
The Kalambo structure is an ancient wooden assembly discovered in 2019 at on the border of and , consisting of two large logs deliberately notched and joined at an angle of approximately 75° to form a foundational platform, dated to approximately 476,000 years ago through techniques. This artifact, recovered from waterlogged sediments along the Kalambo River, represents the earliest known evidence of purposeful for structural purposes by early hominins, predating the earliest evidence of Homo sapiens by approximately 176,000 years. The structure's preservation is exceptional due to the site's anaerobic, water-saturated environment, which prevented decay and allowed for the recovery of intact timber fragments up to 1.4 meters long. Excavations at , a key archaeological locality first investigated in the 1950s and 1960s, have long yielded stone tools and hominin fossils associated with the industry, but the 2019 dig by an international team led by researchers from the uncovered this unprecedented wooden evidence during systematic trenching into the riverbank. The logs, identified as from local hardwood trees such as Combretum zeyheri and Kigelia africana, show clear signs of modification: one features a U-shaped notch made with stone tools, into which the second log was fitted, indicating advanced planning and manipulation of materials far beyond simple tool use. Accompanying finds from nearby layers include four additional wooden implements—a , , cut log, and notched branch—dated between 390,000 and 324,000 years old, further demonstrating sustained traditions in the region. The discovery challenges previous assumptions about early hominin cognitive and technological capabilities, suggesting that pre-Homo sapiens populations, possibly or a related species, engaged in complex behaviors like habitat modification or as early as the Middle Pleistocene. Unlike later prehistoric structures, the Kalambo assembly lacks evidence of permanent but implies intentional joining for practical ends, such as elevating platforms above wet ground or supporting temporary shelters. Published in in 2023, the findings have sparked interdisciplinary interest in , prompting reevaluation of perishable materials in the and highlighting the need for more excavations at waterlogged sites worldwide.

Site Background

Location and Environmental Context

The Kalambo Falls site lies on the border between and in south-central , at the southeastern end of , where the Kalambo River descends a 221-meter . The archaeological deposits are exposed along the riverbanks approximately 33 kilometers west of the town of Mbala in Zambia's Northern Province, at an elevation of around 1,150 meters above . The site has been recognized as a tentative since 2009 due to its prehistoric significance. Geologically, the site features fluvial sediments comprising layered sands, gravels, fine silts, and clays deposited by a moderate- to high-energy sandbed river prone to lateral channel migration. These waterlogged, anaerobic deposits—maintained by a permanently elevated —facilitate exceptional organic preservation by limiting oxygen exposure and bacterial decay. In the Middle Pleistocene, the local paleoenvironment encompassed a periodically inundated bordered by dense forest cover within a broader wooded landscape, offering early hominins reliable access to timber resources such as Combretum zeyheri and Kigelia africana, perennial freshwater from the river and lake, and faunal and floral food sources. As of 2025, the site's stability is jeopardized by ongoing driven by river dynamics, alongside rising water levels linked to variability in the Lake Tanganyika basin, which could inundate and alter the sedimentary profile. Additionally, proposed small-scale hydroelectric developments along the Kalambo River present further risks to the preservation environment through potential alterations in flow regimes.

Historical Archaeological Research at Kalambo Falls

Archaeological investigations at Kalambo Falls commenced in 1953 when J. discovered the site during a surface survey, leading to systematic excavations from 1955 to 1967 that uncovered a stratified sequence of human occupation spanning hundreds of thousands of years. 's work focused on multiple sites along the riverbank, revealing stone tools indicative of early hominin activities, including Oldowan-style choppers from Mode 1 industries and handaxes from Mode 2, alongside evidence of hearths and scattered wooden fragments dated through geological context to approximately 300,000–100,000 years ago. These findings established Kalambo as a pivotal locality for understanding the in south-central Africa, with the wooden pieces—such as a possible modified —hinting at early but lacking definitive structural context. Subsequent phases of research in the and involved collaborative efforts, including those led by Lawrence Barham starting in 1988, which expanded on Clark's trenches through surface collections and targeted digs to further delineate Mode 1 and assemblages. These investigations confirmed the presence of core tools like choppers and refined bifaces such as handaxes, reinforcing Kalambo's role in tracing technological transitions without uncovering evidence of built structures. Polish-Zambian teams contributed during this period by analyzing regional lithic industries, helping to contextualize Kalambo's artifacts within broader Zambian patterns, though primary focus remained on stone-based evidence. Pre-2019 research highlighted significant gaps in the study of organic materials, as preservation challenges in the site's waterlogged sediments limited detailed analysis of wood until advancements in luminescence dating and microscopic techniques emerged in the 2010s. While stone tools and hearths provided robust insights into Acheulean behaviors, the modified wooden hints—exemplified by Clark's 1960s recovery of a sharpened stick—were often attributed to natural decay rather than systematic human intervention, underscoring the need for renewed focus on perishable artifacts.

Discovery and Excavation

2019 Fieldwork Campaign

The 2019 fieldwork campaign at formed a central phase of the Deep Roots of Humanity project (2011–2021), a multidisciplinary initiative funded by the UK's Arts and Humanities Research Council to explore early human technological and behavioral adaptations in Africa. Directed by lead researchers Larry Barham from the and Geoff Duller from , the campaign incorporated close collaboration with Zambian institutions, including the National Heritage Conservation Commission and the Livingstone Museum, as well as local experts such as Perrice Nkombwe from the Moto Moto Museum. This effort built on the site's established associations with tool-making by targeting previously unexamined deeper sediments to recover well-preserved organic remains in waterlogged contexts. The scope of the campaign focused on site BLB, a locality along the Kalambo River between earlier excavation areas Site B and Site C North, selected via to access fluvial deposits altered by river migration since prior surveys. Excavations involved digging 1x1 meter pits to systematically probe the sequence, prioritizing waterlogged layers for their potential to preserve perishable materials like wood alongside stone artifacts. Methodological rigor emphasized minimal disturbance in anaerobic conditions, with teams employing hand trowels for layer-by-layer removal and water-sediment separation via sieving to isolate fragile organics from fine silts and sands. Specialized techniques enhanced data collection and documentation. Optically stimulated luminescence (OSL) sampling targeted quartz grains in sediment profiles to establish chronological frameworks without relying on organic decay, complementing the site's challenging preservation environment. High-resolution 3D captured spatial relationships of features and artifacts through structured light scanning and drone-based imaging, enabling precise digital reconstructions. In a pit at site BLB5 within waterlogged sediments, these methods facilitated the in situ revelation of the wooden structure, preserving its contextual integrity amid associated flakes and cores.

Recovery Process and Initial Findings

During the 2019 fieldwork campaign at , the recovery of the wooden structure at site BLB5 emphasized meticulous handling to protect the fragile organic remains from the waterlogged sediments. The two large logs, interlocked at right angles via a U-shaped notch, were gently excavated partially , lifted within surrounding blocks to preserve their positioning, and immediately wrapped in plastic cling film for retention. They were then stored in water-filled tanks and transported in foam-padded marine plywood boxes to prevent damage during transit. Initial on-site observations noted the logs' visible chopping and scraping marks on the notches, indicating deliberate human modification, alongside nearby smaller wooden tools—such as a wedge and digging stick—in the same sedimentary layer. The structure was embedded among stone flakes, including flake tools, cleavers, and handaxes, within fluvial sands and organic-rich clays that suggested intentional placement in a riverine environment. Handling these artifacts presented substantial challenges due to the high humidity and permanently elevated water table, which risked rapid fungal decay and degradation upon exposure to air. Surface marks on the wood began to deteriorate during initial storage, particularly from sandy contexts, necessitating submerged photogrammetry and reflectance transformation imaging for documentation to counter water pooling and high reflectance issues. This recovery represented the first in-situ wooden structure unearthed at the site, highlighting the unprecedented preservation conditions.

Physical Description

Structural Components

The Kalambo structure comprises two primary wooden components recovered from waterlogged deposits at site BLB5 during the excavations: an upper log designated as Object 1033 and an underlying larger trunk. The upper log, identified as zeyheri wood, measures 141.3 cm in length and 25.6 cm in width, with tapering ends and a U-shaped notch measuring 13.2 cm long by 11.4 cm wide, oriented transverse to its long axis. This notch exhibits clear modification marks, including chopping facets up to 24 mm long and scraping striations up to 12.5 mm in length, indicating deliberate shaping without the use of metal tools. The underlying trunk, larger in diameter than the upper log, features a tapered end that passes through the U-shaped notch, forming an interlocking joint at an angle of approximately 75 degrees. Modifications on this trunk include scraping marks over a 10 cm by 5 cm area with parallel striations, as well as additional shaping on the tapered section, consistent with abrasion and cutting techniques using lithic tools. The components were placed horizontally in the deposit, with the notch alignment suggesting potential load-bearing capability, possibly as part of a platform or foundation base. Both elements were preserved in waterlogged conditions, remaining largely intact despite partial mineralization by silica, and retaining some bark and a near the sapwood on the upper log. The intentional craftsmanship evident in the join and surface modifications underscores early hominin proficiency in for structural purposes.

Associated Wooden Artifacts

In addition to the main structural elements, the excavations at uncovered four modified wooden artifacts, interpreted as tools, which provide evidence of early hominin capabilities. These include a , a , a cut log, and a notched , all shaped using stone tools and preserved in waterlogged sediments. The artifacts demonstrate a range of modification techniques, such as chopping to create facets and striations, scraping to smooth surfaces, and for functional shaping, with some showing signs of or leverage application through stepped cut patterns and compression marks. The , measuring 36.2 cm in length and tapering to a point cut at approximately 60 degrees, features faint parallel linear striations and intercutting convex facets indicative of deliberate work. Recovered from Layer 4-5 below the modern river level at site BLB3, it dates to 476,000 ± 23,000 years ago and likely served for splitting wood or as a portable base for tasks. The , 62.4 cm long with a pointed tip narrowed to 1.3 cm and a base breadth of 11.9 cm, exhibits faint linear striations and small convex facets from scraping; found in Layer 5 above the river level at BLB2, it is dated to 390,000 ± 25,000 years ago and shows tip rounding consistent with use in digging for , such as roots or tubers. A cut log, approximately 59.24 cm long, 29.34 cm wide, and 7.7 cm thick, displays chop marks up to 2.3 cm deep at both ends along with transverse striations, suggesting the use of a hafted for large-scale cutting; this artifact from Layer 5 at BLB4 dates to 324,000 ± 15,000 years ago and points to activities. The notched measures 37.9 cm in length with a 12.3 cm base diameter and features a single chop mark above the tip; recovered from BLB4, it dates to 324,000 ± 15,000 years ago and has an uninterpreted function. All artifacts originate from Layers 4–5, placing them contemporaneous with or slightly younger than the primary structure, and their diverse forms highlight multifunctional roles in , resource extraction, and potential modification.

Scientific Analysis

Dating Methods and Results

The dating of the Kalambo wooden structure relied primarily on techniques applied to and grains extracted from the surrounding fluvial sediments, which trap electrons through exposure to natural after burial and last exposure to or . For younger sediments under 60,000 years old, single-grain optically stimulated (OSL) was used on grains to measure the and calculate burial age. However, for the older layers containing the structure, OSL signals were saturated, necessitating post-infrared stimulated (pIRIRSL) on multi-grain aliquots of potassium-rich s, which provided reliable signals with low anomalous fading rates of about 1.46% per decade. Sixteen sediment samples were collected from the excavation areas (BLB2, BLB3, BLB4, and BLB5) during the 2019 fieldwork, targeting layers immediately bracketing the wooden artifacts to ensure chronological control. The pIRIRSL analysis of samples from BLB3 and BLB5, where the interlocking wooden elements were recovered, yielded a mean age of 476,000 ± 23,000 years ago for the structure-bearing layer, derived from multiple subsamples forming a tight cluster that respected stratigraphic order within 1σ uncertainty. This result incorporates dose rate measurements from in situ gamma spectrometry and accounts for potential fading without requiring correction, as uncorrected ages aligned with the depositional sequence. Supporting the luminescence dates, the wooden structure occurs in direct association with Acheulean stone tools, including flake tools, cleavers, and handaxes, within the same lowermost stratigraphic horizons of a 9-meter fluvial sequence dominated by waterlogged sands and gravels. These artifacts are typologically consistent with the techno-complex, which is broadly dated from approximately 1.76 million to 200,000 years ago across African sites through integrated stratigraphic and geochronological correlations. on associated organic remains returned infinite ages exceeding 50,000 years, confirming the material's antiquity beyond the method's range.

Material and Preservation Studies

The wooden artifacts associated with the Kalambo structure, recovered from waterlogged deposits at , , consist primarily of hardwoods identified through anatomical analysis using scanning electron microscopy (SEM) on transverse, radial, and tangential sections. The main notched log (object 1033, BLB5) and a rectangular log (object 1034, BLB4) are made from Combretum zeyheri (river bushwillow), a species common in riparian environments and noted for its density and resistance to environmental stress in moist settings. Other associated pieces include Kigelia africana (sausage tree) for a tapered object (object 219, BLB2) and a pointed branch (object 660, BLB3), and Ficus spp. for a V-shaped branch (object 661, BLB3), all identified via comparable modern reference samples. Modification traces on these artifacts reveal deliberate working with lithic tools, examined through , reflectance transformation imaging (RTI), and microscopic analysis of surfaces while submerged to prevent degradation. The notched log exhibits a U-shaped cut measuring 13.2 cm long and 11.4 cm wide, with parallel striations up to 12.5 mm long and facets averaging 24 mm, indicative of repeated chopping and scraping actions at angles such as 75° relative to the log's axis. The tapered object shows sinuous striations 42.8 mm long and a pointed end shaped by cuts at approximately 60°, while chop marks on the rectangular log reach depths of 2.3 cm with widths of 13–25 mm. No definitive evidence of heat alteration or damage was observed, though indicated partial silica mineralization consistent with long-term burial without combustion effects. Preservation of the wood stems from the site's taphonomic conditions, particularly the anaerobic, waterlogged sediments formed by fluvial processes along the Kalambo River. The artifacts were embedded in a sequence of fine sands, silts, and organic-rich clays within the lowermost 2 meters of a 9-meter-deep deposit, where a permanently elevated limited oxygen exposure and microbial decay. High organic content in the clay-silt layers further stabilized the wood compared to coarser sandy contexts, enabling survival over hundreds of thousands of years in an environment typically hostile to organic materials. Following recovery during the 2019 excavations, the artifacts underwent non-invasive analyses to document surface features without drying, including RTI for enhanced visualization of tool marks and for compositional insights. To mitigate post-excavation risks such as fungal growth, the wood was maintained submerged in cold tap water with trace amounts of , with no fungal activity detected during study. These conservation measures ensured the integrity of the exceptionally preserved specimens for ongoing research.

Interpretations and Implications

Technological and Behavioral Insights

The discovery of the Kalambo structure provides compelling evidence of advanced technological capabilities among early hominins, particularly in techniques that demonstrate intentional and . The notched log (object 1033) from the 2019 excavations features a deliberate U-shaped cut, measuring 13.2 cm long by 11.4 cm wide, created through scraping and adzing to interlock with another wooden element, suggesting the construction of a platform or walkway. This joinery predates previously known examples of structured woodworking by approximately 400,000 years, as earlier evidence was limited to simple modifications without such interlocking designs. Associated with the toolkit, these modifications were likely achieved using large stone tools like handaxes and cleavers to fell and shape wood from species such as Combretum zeyheri and Kigelia africana, highlighting the co-evolution of stone and perishable wood technologies. Behaviorally, the structure implies a level of sophistication in hominin and settlement patterns, pointing to semi-permanent occupation at the site. The preservation of large wooden artifacts in a environment with stable indicates that hominins selected and processed durable woods to elevate living spaces above the , facilitating sustained use of the area's abundant resources like and . This suggests coordinated group efforts, as the scale of felling and assembly would require multiple individuals working together, potentially reflecting early forms of and communication among Mid-Pleistocene hominins. Dated to at least 476,000 years ago, these findings fill critical gaps in the of perishable technologies, which are typically underrepresented due to decay, and reveal capabilities previously inferred only from wear patterns on stone tools. The technological innovations at Kalambo are attributed to toolmakers during this period. No hominin fossils were found in direct association, so the responsible species remains uncertain, though possibly including or related forms. By integrating wood with stone implements, these hominins not only extended their toolkit's utility but also laid foundational principles for later developments like , where components are combined for enhanced performance. Overall, the structure underscores a shift from opportunistic to more deliberate environmental manipulation, reshaping understandings of early hominin cognition and adaptability.

Comparisons with Other Early Sites

The Kalambo structure, dated to approximately 476,000 years ago, represents the earliest known example of structural woodworking in the archaeological record, distinguishing it from earlier isolated wooden artifacts such as the polished plank fragment from in , which dates to over 780,000 years ago but lacks evidence of intentional joining or construction. While provides evidence of advanced woodworking techniques in a Levantine context, the Kalambo logs—deliberately notched and interlocking—demonstrate a purposeful assembly, potentially forming part of a platform or walkway, absent in the Gesher find. In contrast, iconic East African sites like in , with assemblages dating from 1.7 million to 300,000 years ago, yield abundant stone tools but virtually no preserved organic materials due to the site's arid, open-air conditions that promote rapid decay. Regionally, the Kalambo structure predates later innovations in , such as the bone tools from Border Cave in , which date to around 227,000 years ago and include pointed implements for hunting or processing but no wooden construction. It complements contemporaneous sites in the Zambezi Valley, including Twin Rivers Kopje in , where artifacts from similar periods (approximately 500,000–300,000 years ago) include handaxes and evidence of use, though without preserved wooden structures or direct parallels to the Kalambo's . The Kalambo discovery stands as the first in-situ evidence of wooden architecture from the , surpassing sites like Boxgrove in the UK—dated to about 500,000 years ago and renowned for finely crafted flint handaxes but lacking any organic preservation that could reveal composite technologies. This African evidence challenges longstanding Eurocentric narratives that emphasized stone-tool sophistication in Europe while underestimating early hominin capabilities in perishable materials on the continent, highlighting instead the advanced technical cognition of populations in equatorial environments. As of November 2025, no major discoveries of comparable prehistoric wooden structures have emerged since the 2023 Kalambo report, though the site's waterlogged context underscores the potential for similar finds in Africa's tropical riverine and lacustrine settings, where anaerobic conditions favor organic preservation.

References

  1. https://www.nature.com/articles/s41586-023-06557-9
  2. https://www.smithsonianmag.com/smart-news/archaeologists-uncover-notched-logs-that-may-be-the-oldest-known-wooden-structure-180982942/
  3. https://www.bbc.com/news/science-environment-66846772
  4. https://news.liverpool.ac.uk/2023/09/20/archaeologists-discover-worlds-oldest-wooden-structure/
  5. https://www.science.org/content/article/half-million-year-old-lincoln-logs-may-be-first-wood-structure-made-by-ancient-humans
  6. https://www.cnn.com/2023/09/20/africa/oldest-wooden-structure-zambia-scn
  7. https://the-past.com/feature/built-to-last-extraordinary-ancient-architecture-at-kalambo-falls/
  8. https://www.zambiatourism.com/destinations/waterfalls/kalambo-falls/
  9. https://whc.unesco.org/en/tentativelists/868/
  10. https://www.sciencedirect.com/science/article/pii/S0047248415001104
  11. https://www.aljazeera.com/gallery/2025/6/2/people-in-burundi-struggle-amid-lake-tanganyikas-endless-flooding
  12. https://antiquity.ac.uk/projgall/barham322
  13. https://www.researchgate.net/publication/280932244_Excavations_at_Site_C_North_Kalambo_Falls_Zambia_New_Insights_into_the_Mode_23_Transition_in_South-Central_Africa
  14. https://pure.aber.ac.uk/ws/files/29024098/_21915784_Journal_of_African_Archaeology_Excavations_at_Site_C_North_Kalambo_Falls_Zambia_New_Insights_into_the_Mode_2_3_Transition_in_South_Central_Africa.pdf
  15. https://www.researchgate.net/publication/285918873_100_years_of_archaeological_research_in_zambia_Changing_historical_perspectives
  16. https://www.nytimes.com/2023/09/20/science/ancient-human-woodworking.html
  17. https://deeprootsafrica.wordpress.com/
  18. https://deeprootsafrica.wordpress.com/2019/07/26/a-two-dance-day/
  19. https://datacat.liverpool.ac.uk/2200/
  20. https://www.nature.com/articles/s41599-021-00735-8
  21. https://www.nature.com/articles/s41598-022-14031-1
  22. https://www.sciencedirect.com/science/article/abs/pii/S0277379122002281
  23. http://in-africa.org/wp-content/uploads/2012/12/Barham-2002-JHE-backed-tools-in-MPle-Africa-Twin-Rivers.pdf
  24. https://archaeologymag.com/2023/09/half-a-million-year-old-wooden-structure-in-zambia/
Add your contribution
Related Hubs
User Avatar
No comments yet.