Rock Art Conservation: Floor Stabilisation at Nswatugi Rock Art Site, Matobo Hills Cultural Landscape Senzeni Khumalo, Charity Nyathi, Kelvin Machiwenyika & Todini Runganga

the rock art of the hunter-gatherers in southern africa

Rock Art Conservation

Floor Stabilisation at Nswatugi Rock Art Site, Matobo Hills Cultural Landscape

Senzeni Khumalo, Charity Nyathi, Kelvin Machiwenyika & Todini Runganga

Senzeni Khumalo is a curator of Archaeology based at the Natural History Museum in Bulawayo, Zimbabwe. She holds a Master of Arts in Archaeology. Her research interest is in archaeology and heritage management. Charity Nyathi is a curator of Archaeology based at the Natural History Museum in Bulawayo and the manager for Matobo Hills World Cultural Landscape. She holds a master’s degree in Heritage Management from Midlands State University and her research interests are in rock art, public archaeology and archaeology. Kelvin Machiwenyika is a curator of Archaeology at the Zimbabwe Museum of Human Sciences in Harare. He is responsible for the management of national monuments in the northern regions of Zimbabwe. He holds a master’s degree in Archaeology from the University of Cape Town. His interests are in rock art, Iron Age and Stone Age. Todini Runganga is a curator of Archaeology at the Natural History Museum in Bulawayo. His interests are in rock art, lithic studies and Iron Age. He is also a site manager for Khami World Heritage Site. He holds a master’s degree in Heritage Studies from the University of Zimbabwe.

Nswatugi is a cave which lies at 20°32´08.54´´ S 28°28´42.42´´ E in the Matobo Hills World Heritage Cultural Landscape. It is an impressive narrow cave with a maximum length of 16 meters, and a maximum width of 5,3 meters. The hunter-gatherer paintings are most concentrated on the north-west panel where the painted surface stretches for 9,6 meters in length and 4,8 meters in height. A survey conducted in 2019 revealed that there is at least 162 individual paintings with a broad variety of techniques – monochrome, bi-chrome and shaded polychrome – and colours – white, red, orange, brown and dark-red. Types of images which are depicted include anthropomorphic, zoomorphic and geometric motifs. Nswatugi was declared a national monument in 1937 due to its outstanding hunter-gatherer rock paintings and it is where the oldest human skeleton in Zimbabwe was recovered as well as evidence of Middle Stone Age occupation dating to around 42 000 BP. Walker’s (1995) excavation yielded the oldest known human skeleton in Zimbabwe, dated to 9 500 BP. The cave is also one of the most visited rock art sites in the Matobo Cultural Landscape. This could be due to the fact that it is well published in guide books, well sign-posted and its access is fairly easy. The site also has an interpretative centre which chronicles its scientific value.

State of conservation of Nswatugi Paintings

A condition survey which was carried out in 2019 revealed a number of factors which are affecting the paintings. One of the biggest threats to the painting is dust. Dust is confined to lower sections of painted surface, approximately one meter from the ground. The dust accumulated over a long period through different phases of occupation and use. It is generally agreed that the cave

was occupied quite intensively several times between 10 000 and 6 000 year s ago, and then abandoned (Walker, 1995). The cave was then used as a granary by farming communities in the nineteenth century. In the 1920s, a grain-bin which was at the tip end of the cave was recorded (Jones, 1926), however it has since disintegrated. There is also a suggestion that the cave was used as a cattle kraal during civil wars. Ranger (1999) also suggests that the cave could have been used as a rainmaking shrine by contemporary communities before they were moved away to make way for the creation of the Rhodes Matopos National Park in 1926. Currently, the cave receives a high volume of tourists due to its exceptional paintings. These activities contributed to the development of a film of dust which has obliterated the lower sections of the painted surfaces (Fig. 1). The cave is also being affected by extensive flaking of granite rock due to weathering, and significant portions of painted area are being lost. The painted surface is also damaged by lichens which are accumulating around the mouth of the cave, and by accumulation of bird droppings.

Floor stabilization project

A floor stabilisation project was under taken in October 2019. The project was led by the National Museums and Monuments of Zimbabwe (NMMZ) technical team, which included archaeologists, traditional stone masons and a student from Midlands State U n i ve r s i t y. T h e t e c h n i c a l t e a m a l s o d rew yo u t h participants from the local community. The project was conceived as part of preventive conservation of rock art. This is against a background that cleaning of dust is a delicate process which may damage pigment and painted surfaces. The main objective of the project was to curb the accumulation of dust on painted surfaces, which is raised due to high and uncontrolled visitor traffic to the cave. The project also stabilised the slopes of the cave to har ness soil erosion. The process was infor med by requirements of heritage conser vation international practices, which are encouraging the implementation of reversible conservation methods (ICOMOS 2017). The project team also emphasised on documenting all the steps for future reference.

Figure 1: Film of dust on the paintings (image courtesy: Natural History Museum of Zimbabwe).

Figure 2: linchens on cave walls (image courtesy: Natural History Museum of Zimbabwe).

Figure 3: Chipping of the rock and flaking of paintings (image courtesy: Natural History Museum of Zimbabwe).

the rock art of the hunter-gatherers in southern africa

The procedure for stabilisation of cave floor included 4 steps:

Step 1: The cave floor and paintings were thoroughly documented using both photographs and text. The photographs will be used for future monitoring. All the digital photographs are stored at the Natural History Museum in Bulawayo.

Step 2: The floor was levelled by removing debris using a rake. This was done to create an even ground for laying of sand soil.

Step 3: The cave floor was covered with a ten centimetre thick layer of dry and salt-sand soil to facilitate future excavations. The sand soil also marked a separate of ashy archaeological rich layer and backfill.

Step 4: Granite stones slabs were sought around the area and laid on top of the sand soil. The granite stone were shaped and closely packed to create a stone-floor which visitors can comfortably step on. There slabs were laid without adding binding substances such as mortar or cement (Fig. 4 & 5).

Conclusion

Rock art sites are among the most difficult cultural resources to preserve. The difficulty stems from the frag ile nature of the ar t due to general physical environment and tourism. Therefore, the success of the project will largely depend on continuous monitoring and buy-in from the general public, visitors and touroperators. Currently, NMMZ is working on revamping the interpretive centre at Nswatugi, and it is critical to provide information on the dos and don'ts. It is also critical to carry out periodic impact assessments of the project on the site. This will inform replication of the same project on other rock art sites in the cultural landscape. However, what is lacking at the moment is baseline data for monitoring.

Figure 4: Covering pulverised floor with riversand (image courtesy: Natural History Museum of Zimbabwe).

Figure 5: Stabilized floor with granite slabs (image courtesy: Natural History Museum of Zimbabwe).

Bibliography

ICOMOS, 2017, Approaches to the Conservation of Twentieth-Century Cultural Heritage, Madrid-New Delhi Document. JONES, N., 1926, The Stone Age of Rhodesia, London, Oxford University Press. JONES, N., 1933, “Excavations at Nswatugi and Madiliyangwa, and notes on new sites located and examined in the Matobo Hills, Southern Rhodesia, 1932”, Occasional Papers of National Museums of Southern Rhodesia, 2, p. 1-44. RANGER, T., 1999,Voices from the rocks: Nature, Culture and History in the Matopos Hills of Zimbabwe, Indiana, Baobab Books. WALKER, N.J., 1995, Late Pleistocene and Holocene Hunter-gatherers of Matopos, Uppsala, Studies in African Archaeology, 10.