The archaeology of Trou Al'Wesse

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Here we present data on the different human occupations, beginning with the most recent - the Early Neolithic - and ending with the oldest - the Mousterian.



Human group


Date range (uncal. BP)


First farmers in Belgium

Early Neolithic

~5,900 BP

4b-alpha to delta

Last hunter-gatherers in Belgium

Early to Late Mesolithic

9,000-~6,500 BP


Early modern humans


32-36,000 BP




~ 60,000 BP


Neolithic occupations

Stratum 4a contains traces of an Early Neolithic occupations, based on the presence of ceramic sherds attributed to the LBK and probable domesticated fauna.


Among the more interesting discoveries, several stone retouchers on elongated river cobbles and a perforated bone pendant have been found. The pendant has been shaped to imitate the vestigial canine of a deer, a common practice across Europe as yet unique in Belgium. Real and imitation deer canine pendants have been found in burial contexts in the Paris Basin.





The first farmers arrived in Belgium with an already advanced Neolithic culture. In contrast to the last hunter-gatherers still living in Belgium, nomadic or semi-nomadic, the Neolithic groups lived in villages and had an agricultural economy based on cereal production. They also raised domesticated animals (cattle, sheep, goat, pig), made pottery and stored grains. This way of life contrasts sharply with that of the Mesolithic hunter-gatherers because it was linked to the land, and thus with a more fixed notion of territory.


In Belgium, the first Neolithic occupations were concentrated on the plateaux north of the Meuse River, where the fertile loess was highly suitable for agriculture. Mesolithic groups were still present, and processes of Neolithization (acculturation or assimilation) have been the subject of intense research across Europe.


Since the discovery of Trou Al'Wesse, the presence of ceramic sherds in stratum 4 led to hypotheses concerning contacts between Mesolithic and Neolithic populations, such as possible trade exchanges or pottery-making by Mesolithic groups.


The analysis of the spatial distribution of the ceramic sherds from recent excavations, as well as stratigraphic analysis, clearly demonstrate the exists of different occupations within straigraphic complex 4. This complex is now divided into  two separate strata: stratum 4a containing the Neolithic occupations, and 4b containing Mesolithic occupations. All of the sherds have been found in 4a and form a uniform assemblage attributed to the LBK, the Early Neolithic in Belgium. Lithic artifacts found near the base of 4a have been attributed to the Mesolithic, displaced from the underlying 4b by slope processes on the terrace. No Neolithic elements have as yet been found in stratum 4b, which contains a dense concentration of lithic artfiacts, associated with bone fragments of wild animals and charred organic remains, primarily hazelnut shell.


The Early Neolithic is thus attested at Trou Al’Wesse ( 6th millennium BC), south of the Meuse and the villages on the Hesbaye Plateau. Trou Al'Wesse may have served as a short-term hunting camp or shelter for herders.


At the back of the cave, in the chimney joining the plateau, early excavators discovered a collective burial dating to the Neolithic. The human remains were recently studied by Ph. Masy, and more information can be found in his publication: MASY Ph., 1993, La sépulture collective néolithique du Trou Al'Wesse à Modave (province de Liège). Bulletin des Chercheurs de la Wallonie 33, p. 81-99.


Other isolated human remains have been recovered from test pits on the alluvial plain in front of the cave, undertaken by J. Destexhe at the end of the 1950s-early 1970s.



Mesolithic occupations

At the end of the Pleistocene, following the progressive warming of the global climate, we enter the current interglacial - the Holocene. The material culture of prehistoric people adapted to environmental changes and the Mesolithic is characterized by the development of microlithic industries.


In Belgium, the Mesolithic is represented by sites in caves and rock shelters in Wallonia (e.g., Trou Al'Wesse, Abri du Pape, Station Leduc at Remouchamps, grotte Lechat at Hamoir), open-air sites in Flanders (notably, Melsele 'Hof ten Damme', Doel Deurganckdok, and Verrebroek Dok, among others), two open-air sites in Wallonia (Place Saint Lambert in Liège and Grognon in Namur), a series of collective and individual burials in Wallonia (Grotte Margaux, Abri Autours, Claminforge, Petit-Ri, Faille du Burin, Lombeau, and most recently, Bois Laiterie), and numerous surface finds in the Ourthe Basin in eastern Belgium and near Ath and Mons in the province of Hainaut.


The site of Trou Al'Wesse is, however, the only Belgian site with a stratified sequence containing occupations from the end of the Early Mesolithic to the Late Mesolithic.


Recent excavations carried out under the direction of F. Collin in the 1990s and those currently in progress have focused on the way of life of these hunter-gatherers. Lithic assemblages contains cores and tools, particularly geometric microliths, and abundant knapping debris rsulting from knapping activity taking place at the site, on local and non-local flint. The technology and typology of the Late Mesolithic assemblage from the L-M trench excavation (1990s) was studied by Charlotte Derclaye (1999). Further analyses will clarify other aspects of human behavior, for example, the presence of activity zones, cultural change within the Mesolithic, site function and the role of Trou Al'Wesse within the larger territory.


The facies of Mesolithic occupations in stratum 4b are extremely rich, both in lithic and faunal material. The organic material -charred remains, microfauna, mollusks, and larger fauna - are being analyzed for environmental studies. A sample column (J9) was selected for flotation to recover micro-vegetal remains.



Mesolithic Tools from stratum 4b


Cores from stratum 4b



The Pleistocene fauna from stratum 15a

Stratum 15a, overlying the Aurignacian occupation, is archaeologically sterile, but rich in fauna: carnivores, herbivores, rodents. This fauna is being analyzed for the environmental study and to complete the stratigraphic sequence.




Aurignacian occupation

Aurignacian artifacts were discovered by the first excavators in the 19th century. During the first phase of modern excavations, F. Collin excavated a 2 m²  test pit in squares L-M 5 to reach bedrock. In these squares, in stratum 15b, he also discovered lithic and faunal material attributed to the Aurignacian.


The Aurignacian is known from several caves in the Meuse Basin. M. Otte studied these collections and classified them in three successive groupes (Otte, 1979). The first includes the sites of Spy, Goyet, the Trou du Chêne and part of Trou Magrite. Trou Al'Wesse is attributed to the early phase, notably by the presence of a split-based point. The second group includes the sites of Trou du Diable at Hastière, Princesse Pauline Cave at Marche-les-Dames, grotte de la Cave at Ben-Ahin, and Fonds-de-Forêt. The most recent group includes Trou du Renard and Trou Reuviau at Furfooz, a part of Trou Magrite and part of Princess Pauline Cave.


The majority of these collections come from early excavations lacking contextual data. The Aurignacian stratum at Trou Al'Wesse, along with the recently excavated Grotte Walou, is thus crucial for understanding of the cave occupations of the first modern humans in Belgium.


In 2000-2002, the same scientific team excavated the open-air Aurignacian workshop at Maisières-Canal (Miller, Haesaerts & Otte [dirs.], 2004).



Aurignacian tools from 19th century excavations

(after Otte 1979)


Mousterian occupations

Neandertals were the first human occupants at Trou Al'Wesse. Evolved from Homo erectus in Europe around 250,000 years ago, they survived more than 200,000 years. The most recent Neandertals, dated to 36,000 BP, were discovered at Saint-Césaire in France in 1979 by F. Lévêque and B. Vandermeersch.


In Belgium, Neandertals were first discovered at Engis (child's calvarium) by Ph.-Ch. Schmerling in 1830. In 1866, a mandible was discovered at La Naulette, followed by the skeletons at Spy (1886) and a femur at Fonds-de-Forêt (1895). An isolated molar was found at Trou de l’Abîme at Couvin (1984), a child's mandible at Scladina Cave (1993) as well as numerous teeth which refit to the mandible and a part of the maxilla, and an isolated molar at Walou  Cave (1999).


The Neandertals occupied northern Europe during the interglacial periods, when the climate was temperate and fauna abundant.


The ocean floors, which undergo continuous sediment deposition, and polar ice sheets, record terrestrial climatic variations, in particular by the proportion of oxygen isotopes (16O et 18O); oxygen-isotope stages (OIS) have been defined on this basis.


At Trou Al'Wesse, the excavations of J. Fraipont, M. Lohest and I. Braconnier yielded a Mousterian assemblage. Its analysis by M. Ulrix-Closset (1975) attributed the assemblage to Mousterian of Quina type (defined after the site of La Quina, in Charente, France). This facies of the Mousterian is characterized by the presence of sidescrapers, particularly transversal, shaped by Quina retouch, which is oblique and scalar. The Levallois method is rare.



Mousterian tools from 19th century excavations


(after Ulrix Closset 1975)


Absolute dates

Several dates were obtained during the first phase of this project. New dates for the Neolithic and Mesolithic occupations from complex 4 are in progress and the entire sequence will be dated over the course of the project.


Lab ref.




Date BP (uncal.)

Cal. Date

(2 sigma)

Cultural attribution


Inside cave

Profile  gL/gM 10

sample 2

y: 9.60

z: -3.74 cm BD


charcoal (Quercus)

550 ± 40 BP

cal AD 1310-1370


cal AD 1380-1430



L9, -485 cm



5045 ± 45




L16, -688-702 cm



5950 ± 70


Early Neolithic




Human cranial fragment

6540 +/- 45


5620-5370 cal BC


Recent/Final Mesolithic


L14, -688-702 cm



6650 ± 70


Recent Mesolithic


out of context


sagaie point

30750 ± 850




I8B, déc. 3

sample 14

-4.56 to -4.64 cm BD

4a upper


barley grain

1440 ± 40 BP

cal AD 540-660



I7C, déc. 10, bag 442

-4.57 to -4.67 cm BD


facies alpha

charred hazelnut shell

9000 ± 40

8280-8210 cal BC

end of Early Mesolithic

Lyon 212

out of context



32325 ± 660







36500 ± 1100







41100 ± 2300




Updated 14 March 2006