Wassu Stone Circles Quarry Site

Description

The quarry site is located on a laterite ridge to the east of the Wassu stone circles site. The ridge is covered with grass and other vegetation  which obscures the rock outcrop from a distance but the quarries are easy to identify having been open-cast quarried for the stone. The most obvious form is a pillar-shaped quarry where the stone was removed and probably finished. Other shallow cuts and stepped platforms also indicate quarry activity but may also imply natural erosion features. Some partially dressed stones remain in situ but are fractured;which probably led to their abandonment. The site lies on the edge of the outcrop which accommodated the removal of the stone from its matrix. Another quarry lies to the ESE. The quarries appear to have been exploited in no systematic way just for ease of access to the raw material and transportation of the finished products.

From the visible remains in situ,the stones appear to have been removed in blocks, as it occurs naturally and it is then dressed, presumably at the quarry site. The ridge is littered with broken fragments of stone. The number of quarries does not reflect the magnitude of the Wassu circles and its outliers although present plant growth cover prohibits an accurate assessment of the extent of the quarries.

Justification of Outstanding Universal Value

The Stone Circles of the Senegambia was inscribed on the World Heritage List in 2006 represent a vast extensive megalithic  monumental building tradition manifest in 1000 circles spread across one of Africa's major river valleys. The four stone circle clusters of Wassu and Kerbatch in the Gambia and Sine Ngayen and Wanar in Senegal constitute the most dense concentration in the zone and are of outstanding universal value as products of a sophisticated,highly organized and productive society whose tradition of stone circle construction,associated with burials,seem to have persisted in the area for over a millennia.

The first significant stage in the construction process of the stone circles is the identification of suitable lateritic outcrops for the carving of the stones. Although laterite is widely found in the region, the identification of compact and homogeneous outcrops with minimal natural weaknesses require great knowledge of the local geology. Without this expertise it would have been almost impossible to exploit the quarries which gave birth to the monoliths.

The second remarkable aspect relates to the carving and extraction of the monoliths. The cutting and extraction would have presented formidable difficulties. The monoliths broken in the process and left on the spot, especially at the Wassu Quarry, often show traces of microscopic cracks or differential ferruginisations  which could have caused them to split in the process. Consequently one needed considerable technical ability and a good knowledge of the raw material to achieve the required size of monoliths and extract them accordingly.

The transport and erection of the monoliths on the other hand, judging from the distances between the quarries and the emplacements, presupposes a well grounded social organization to mobilize the huge labour forces necessary for the transportation and emplacement of the lateritic blocks which could weigh up to7 tons in some instances.

The quarries close to the Wassu stone circles have been verified to be the source of most of the stones used at the Wassu circles site. With evidence of varying quarrying methods as well as the adjacent grinding groves used for sharpening the iron implements required in the quarrying process, the quarry site makes the Wassu site and the megalithic complex in general more complete by adding to our knowledge of the process of producing the monoliths and the burden of transporting them to site for erection.The quarry site also speaks to the iron working tradition of the society that was responsible for constructing the megalithic phenomena and their astounding knowledge of the local geology.

Statements of authenticity and/or integrity

The Quarry site at Wassu manifests a high degree of authenticity and integrity. Firstly the site is located on the laterite hill from where the stones at the Wassu site were quarried. Apart from the presence of stones broken during the quarrying or transportation process and abandoned on the site, there is also evidence of the various possible quarrying methods. Also in-situ are the grinding groves,which provide evidence of use for sharpening the iron implements which were indispensable to the quarrying process.

Comparison with other similar properties

Though stone circles are found in many parts of the world,nowhere are they made from laterite. Moreover, the origins of the stones in most of the other  extant circles,including those at Stonehenge, are also speculative. Lying in close proximity to the Wassu Stone Circles site, the Wassu quarry provides incontrovertible evidence of the origin of the Wassu stones, as different from other circle sites the origin of whose stones are at times more than 20 kilometres away.