Regard typo-technologique sur les productions lithiques foliacées du Solutréen de la vallée de l’Erve (Mayenne, France)
Authors: Biard Miguel , Hinguant Stéphan 
Published: April 2018

Since the end of the 19th century, clandestine or academic excavations have brought to light a huge number of laurel and willow-leaf pieces or fragments, most of them coming from the Rochefort, La Chèvre, La Dérouine, Margot and Le Plessis caves, which are the main cavities along the Erve valley (Mayenne, France). Only a part of these pieces has been studied with attempts at chronological and typological reconstitutions being submitted. Since 2006, new excavations in Grotte Rochefort and a new study of the earlier collections allow us today to redefine the Solutrean era in the Erve valley, in particular thanks to the multidisciplinarity of the interventions and the contribution of coherent 14C dates. The excavations of the Solutrean layer in Grotte Rochefort enabled us to unearth a lithic assemblage of approximately 2,000 artefacts. These materials were found in the narrowest and lowest part of the cavity. This observation, associated with the barely coherent spatial distribution, raises the issue of the nature of the occupation of this area of the cave, which we tend to call a rejection zone. The corpus is mainly made up of broken pieces and, except for a few beautiful complete blades, the collection is above all characterized by a high rate of fragmentation. Seventy-one leaf-shaped pieces belonging to this lithic assemblage from Grotte Rochefort are studied here. The presence of numerous spalls corresponding to the production of bifacial pieces is an important characteristic of this corpus, showing that knapping activities did take place inside the cavity itself. The siliceous materials used by Solutrean people here are mainly silicified sandstones (‘ grès lustrés’), the closest deposits of which are located 30 km (approx. 18.6 miles) north of the cave. Above and beyond being part of a common good-quality toolkit, the laurel-leaves and willow-leaves — both ‘ type fossils’ — are an illustration of the gestures and technical choices of the Solutrean knappers, but also raise the question of the purpose of these objects. All of them were small leaf-shaped pieces. Does this mean that they were the result of a cultural choice or of an economical constraint, such as a shortage of raw material forcing the knappers to proceed with the systematic resharpening of their tools ? The series is then compared — in terms of typo-technology — with other laurel-leaves from an earlier collection of the porch area of Grotte de la Dérouine. The Rochefort and Dérouine caves are only 300 m (approx. 328 yards) apart, yet they have yielded very different assemblages. Thus, both are opposed in terms of the choice of raw materials (the Solutreans predominantly chose silicified sandstone and millstone in the former — Rochefort — and flint in the latter — Dérouine) but also regarding the morphology of the laurel-leaves, the kind of supports they used, the abandonment phases, etc. The question of the synchrony and/ or of the status of both sites stems from these observations, although each of them is clearly related to the laurel-leaf Middle Solutrean, a period characterized by the absence of flat-sided points or notched points, circa 19500 BP. The items collected from the recent excavations, along with their reliable chrono-stratigraphic context and the gathering of the whole lithic assemblage (including flakes and micro-debris through sifting) enable us today to better analyse the operating processes used by the Solutrean knappers to produce their tools. We thus tried to identify which products were favoured by knappers for the making of laurel-leaves. Though some bigger shaping flakes may have been chosen, the main supports are wide blades. Their characteristic is their average and somewhat standardized dimensions, with a 30+ mm width and a thickness varying from 4 to 10 mm. This leads us to suspect that these supports were predetermined because their width is obtained after setting in place several arrises in order to flatten the core’s curve before extracting the blade. The butts of the striking platforms of these supports are wide ribs which were strongly abraded. So far we do not have any complete support, but the discovery of portions of irregular or uneven wide blades indicates that only the parts corresponding to the standards of the desired points or leaves were transformed. The early collection from the porch of Grotte de la Dérouine is obviously characterized by the gaps due to the way in which the excavations were conducted and by the inevitable sorting carried out in the 19th century ; the research in Grotte Rochefort remains partial and is probably only related to a rejection zone. This being stated, the validity of the corpuses and results presented could be contested. However, with a total number of laurel-leaves that is almost identical and sufficiently important for each site (46/ 56), the first elements of diagnosis and the comparisons do show real differences. Other than the choice of their materials, the technological criteria put forward to try to explain these observations point to that of the supports selected by the knappers to create their leaf-shaped pieces : mainly flakes and blades in Grotte Rochefort and, rather, central masses of raw material in Grotte de la Dérouine. Also, although preforms and complete pieces are more numerous on this latter site, we do not find there — as is the case in Grotte Rochefort — any final products, nor any sharpening pieces or laurel-leaf reworkings. On a typological note, the large and medium-sized modules of the leaves from Grotte de la Dérouine seem very different from the small pieces from Grotte Rochefort. Finally, and possibly isolated from any functional purpose, the former site’s pieces are characterized by a noticeable proportion of asymmetrical leaves, which is a criteria that is not to be found in Grotte Rochefort. This article is a first attempt at tackling the subject of leaf-shaped pieces from the site, based on the results of techno-typological analyses, and studied according to functional questions, finally raising the issue of the status of the said occupations.