There have been various problems with the definition of terms in archaeology, with terms being employed in different ways by different writers (Harris 1989, 1996b; Smith 2001).  The key terms used in the thesis have therefore been listed here to clarify how they are being used.

Adaptive Strategies

Application of a combination of strategies, traditional or new, to meet survival needs or living preferences for sustainability.

Archaeological record

There is a process of translation between what lies in the ground and what might emerge in interpretative schemes (Barrett 1994, p.5; Lucas 2012; McFayden 2010, p.46).  Ever since Linda Patrik’s question “Is there an archaeological record?” in which she draws attention to five different ways in which the term is commonly used (Patrik 1985, p.29-30), it has become necessary to be explicit about how the term is being employed.  In essence the term record implies that archaeological remains have information to impart.  Patrik distinguishes between physical versus textual models (1985 p.33), both of which accept that there are patterns to be found, with each prioritizing aspects of the archaeological data over others.   Lucas, in reconsidering the issue of the archaeological record in a book dedicated to the subject (Lucas 2012) adopts an approach that centres the discussion in archaeological theory but ultimately puts the onus on his readers to reconsider the role of archaeology and what it can realistically achieve.

I am using the term in the most basic sense that an archaeological record consists of material remains that will later be subjected to interpretation.  This is an inductive rather than deductive process.  The term “record” implies no more than that the data is potentially informative.  If the record is fragmented, represented by a small sample or is otherwise incomplete, it will be less likely to produce information for interpretation and may be misrepresented.

Capital

In prehistoric communities the security or sustainability of a community cannot be measured in terms of a currency value.  Other ways of rating and comparing items as something of value must be achieved.  Numbers may still be used to assign value to commodities (capital assets), but they will be based upon subjective evaluations.  These numbers make comparisons explicit and transparent, but do not imply an inherent capital value or statistical significance.

Community

A human grouping that is both mutable and renegotiable, composed of people who recognize and acknowledge each other and define themselves in terms of each other either temporarily or permanently and are bound together by more than locality or language, and share locations but may split into smaller groups and reform as required.  Communities may be porous, accepting new members and losing members to other communities.  Communities share ideologies and may conceptualize and materialize identify based on ideology, and may include herds and the dead in their own definitions of their communal identity.

Coping strategies

The techniques used to tackle declining food availability in abnormal seasons, as an extension or diversification of an otherwise successful system of livelihood management.

Culture (see also Material Culture)

Ideas held within a society and expressed by that society.  Ideas may include beliefs, traditions and ideologies based on the past, but may also include responses to change, and confrontation of an uncertain future.  Modes of expression include literature, art, music and material output. These may be employed, deliberately or otherwise, to mediate between aspects of complex social relationships and networks.

Data

I use the term data to indicate the raw materials of the archaeological record that later become subject to interpretation.  The moment that any attempt is made to translate the data into information, a transition has occurred.

Drylands

The FAO (Food and Agriculture Organization of the United Nations) defines a dryland as a region with a growing period of between 1 to 179 days, which includes arid, semi-arid and dry sub-humid environments (FAO 2000, p.19).  Further, “dryland areas are ‘fragile’ in that they are extremely vulnerable to land degradation resulting from over-grazing and other forms of inappropriate land use” (FAO 2000, p.17).  This definition has been adopted in this thesis.

Ecosystem

The combination, at any given time, of biodiversity and water availability, the two essentials for food acquisition and production.

Ethnicity

I have borrowed Diaz-Andreu’s definition of ethnicity as “that aspect of a person’s self-conceptualization and his or her conceptualization by other individuals that results from identification with one or more broader groups on the basis of perceived cultural differentiation and belief in common descent” Diaz-Andreu (2015, p.103). She expands this to state the ethnicity is multidimensional because people are not confined to identifying themselves with one category, group or broader scheme of identity and may have broad affiliations.  The emphasis here is on how a person perceives themselves and how they define themselves in relation to other groups of peoples, including communities, and accepts that these may change over time.  Ethnicity is about highly dynamic differentiation and identity, not merely living arrangements.  It may be fluid both on an individual and a group basis.  In an earlier paper Diaz-Andreu also emphasized that archaeologists “cannot study ethnic identity in isolation from other types of identifications – gender, religion, status etc – as all of them will be at play” (1998, p.199) and this is an important consideration, making comments on ethnicity particularly difficult for archaeologists.

Groups

Small units of people who identify themselves with each other and co-operate, or components within communities when communities retain the flexibility to divide and reform when expedient.  Functional and socially defined units.

Group identity

Any set of characteristics that suggest not only a common identity but the desire to express that identity.

Heuristics

Experience-based techniques to assist with decision analysis and problem solving.

Identity

The concept of identity that is adhered to throughout is expressed by White and Beaudry 2009: “The concept of identity is complicated, paradoxical, and culturally situated in time, place, and society. Identity is at once both imposed by others and self-imposed, and is continuously asserted and reasserted in ways that are fluid and fixed. Identity can lie at the individual level and at the broadest of imaginable scales as it defines a person both as part of a group and as an individual.”  As such, identity can be sought at the individual and the community levels and at all points in between.  I suggest that identity can be located in the repeated signals incorporated into material output.  Indicators such as personal ornamentation, ceramic decoration and lithic style all fit into this picture.

Ideology

Ideals, ideas, belifs and values that act together to inform social and economic structures and processes.

Inputs

All costs (energy, capital, weather etc) associated with a given economy. They may include purchased items (e.g. those exchanged/traded) and non-purchased items (e.g. light, temperature, rainfall). Inputs may have positive and negative impacts.  For example the introduction of livestock which requires pasture may have an immediate benefit to the community but may have a long term detrimental effect on the environment.

Landscape

The term landscape is used throughout the thesis to indicate the contemporary topography and environment, as well as the overlays of meaning allocated to them by successive generations of inhabitants who move through them, settle within them, employ their multiple benefits and return to them.  A locality is defined as an area that is occupied within that landscape, and can be made up of sites, camps and events, as well as localized topographical features and environmental settings.  A site is a concentration of human activity, usually termed a settlement in archaeological literature, and may be any size.  Camps are small concentrations of human activity away from the main settlement.  They tend to be specialized and short term, used as hunting bases, material acquisitions and manufacturing sites, amongst others. Events are the smallest of all, and may consist of a single hearth, a single manufacturing site, or the temporary presence of one or two individuals.  In all cases they may represent interactions between economic, ethnic and cultural spheres (Lightfoot and Martinez 1995).

Livelihood

The term “livelihood” is used to incorporate both economic activities and social values.  Both components are included within a community’s overall objectives for a sustainable and satisfactory existence.  It is assumed, however, that where risk and uncertainty exist the requirement for economic sustainability will override all other objectives except, perhaps, those embedded in religious belief and deeply felt social tradition.  However, religious traditions very often incorporate ideas about the safety of the community.  An understanding of livelihood requirements is central to an understanding of decision making criteria.

A number of writers (e.g. Harvey 2000; Sen 1999) have pointed to the value of livelihood requirements in the context of understanding decision making criteria.  Religion often incorporates those ideal utility requirements but are usually difficult to detect archaeologically.

Material Culture

The material expression of culture (see above).  Objects, materials and human-adapted landscapes that incorporate ideas held within a society and as a response (or responses) to transformative or transactional social conditions.  Ideas may include beliefs, traditions and ideologies based on the past, but may also incorporate the need to confront the future.

Model

A device that conceptualizes a set of ideas about how something operates.  It is a simplified representation of a much more complex set of operational systems or processes used with a view to understanding how they work.

Neolithic

Wherever possible, I have avoided use of the term Neolithic, a term originally identified with early food production in the Near East and Europe, which has crept into Saharan terminology.   One of the main problems with the term is that has become clear that there is single set of characteristics that defines a homogenous “Neolithic.” (Bailey et al 2005; Bailey and Whittle 2005; Bernbeck 2008; Casey 2005; Gifford-Gonzalez 2005; Jarman 1971; Shaw 1989a; Shirai 2013; Smith A.B. 2013; Stahl 1999; Sinclair et al 1993; Thomas 2003, p.72).  In “(Un)Settling the Neolithic” (Bailey et al 2005) the contributors each demonstrate how standard assumptions about the form and character of the Neolithic are flawed, that type-sites can set expectations that are not necessarily valid, and that the amount of variation is considerable.  There is plenty of evidence that many so-called Neolithic sites were actually associated with a variety of mobile lifestyles at different scales (Bailey and Whittle 2005; Boric 2005; Halstead 2005; Jochim 1991; Kent 1989; Milner 2005; Rafferty 1985).   Garrard et al (1996, p.218) have shown that the Near Eastern model of a fully mixed agricultural package is only valid for a few areas in the Near East, whilst in other areas more specialized choices were made (e.g. Smith, A.B. 2014, p.5-22).  A number of writers have challenged the idea that there is a firm split between a mobile way of life and a sedentary agricultural one (Bernbeck 2008, p.45-49; Bogucki 1995; Dennell 1995; B. Smith 2001).

In the Sahara, the pattern of “Neolithization” reverses the Near Eastern pattern of domesticated plants and pottery followed by domesticated animals (Marshall and Hildebrand 2002).  In the semi-arid areas of the eastern Sahara there is no evidence that in the early and mid-Holocene plants were ever domesticated.  The presence of pottery and a lithic toolkit that differed substantially from the preceding ones required a different designation and the terms “Neolithic” and “Neolithization” were widely adopted by scholars like Arkell (1953), Marks and Mohammed-Ali (1991) and Wendorf, Schild and Associates (2001) and are common in introductory syntheses of Egyptian prehistory (Bard 2008; Midant-Reynes 1992; Tassie 2014; Wengrow 2006; Wenke 2009). Wendorf and Schild (1980) considered alternative terms for Nabta Playa but opted to retain the term Neolithic because “satisfactory substitutes could not be found” (1980, p.279).

Although the term Neolithic has not been used consistently in eastern Saharan research, it has been impossible to avoid the titles for archaeological units that have been applied by publications.

Numinous

Something that possesses a strong spiritual, supernatural or religious quality, which may or may not be associated with a deity or deities.  The term is useful because it avoids assigning a specific modern concept of belief or divinity to often ambivalent archaeological material.

Palimpsests

Primary Context Palimpsests
The horizontal spatial organization of a site refers to the way in which artefacts and other materials have been deposited on a surface at any one time, reflecting different periods, activities and ideas. Where such horizontal levels are superimposed, a chronological relationship exists, and occupation histories may be reconstructed to a greater or lesser degree, depending on the quality of the raw data.  In some cases, however, objects that were deposited over time find themselves sharing the same surface.  One example of this is deflation, where lighter materials and soils are carried away by the wind leaving objects of multiple periods on the same surface.  Where sites are undisturbed by further processes these are often called in-situ scatters or primary context palimpsests, also termed “spatial palimpsests” by Bailey (2007) and may preserve the original spatial distribution of the artefacts as they were deposited, although it may be difficult or impossible to know which objects were contemporary with others.  This is the main sort of palimpsest encountered in the eastern Sahara.

Cumulative Palimpsests
Where horizontal distribution has been disturbed by human interference or natural processes, causing even contemporary objects to lose their spatial relationship with each other, these are often referred to as artefact scatters (Historic England 2012, p.9), surface scatters or cumulative palimpsests (Bailey 2007), because the original organization of objects has been literally scattered near to but out of their original context (Historic England 2000, p.2). A classic example of this is found in northwest European ploughed fields, which are rich source of prehistoric lithic and ceramic objects, which have been removed from both their original temporal and spatial context, and which may or may not overlie earlier deposits.  Not only is temporal resolution lost but any attempts at spatial analysis would be redundant.

Secondary Context Palimpsests
Artefact scatters are at their most extreme in cases when artefacts have been removed from their original context by forces, usually natural, that have placed them at some distance from their original context.  These are secondary context sites which “may comprise large aggregations of artefacts which provide important evidence on the early human occupation of a particular catchment or region” (Historic England 2012, p.9).  Early and Middle Palaeolithic sites in areas of glacial activity in northwest Europe, or in the fluvial activity of wadis of the eastern Sahara are both good examples:  in both cases natural forces have carried materials away from where they were originally discarded, depositing them in new locations.  In these cases there is no temporal or spatial information available and only the tools themselves survive.

Other types of palimpsests are Bailey’s true palimpsest, in which all traces of previous activity has been removed except for the most recent, and his temporal palimpsest, which form part of the same deposit but include items dating to different ages. A museum is a temporal palimpsest, containing items from different periods, but an archaeological example might be a grave that includes ancestral as well as contemporary objects.  Bailey also adds palimpsests of meaning to his list:  “the succession of meanings acquired by a particular object, or group of objects, as a result of the different uses, contexts of use and associations to which they have been exposed from the original moment of manufacture to their current resting place” and may be applied to individual objects or buildings, and which may be perceived in different ways be different individuals (2007, p.208).

Finally, it should be noted that there is a case to be made for seeing all archaeological layers as palimpsests, whether or not they occur in a stratigraphic sequence (Dunnell and Dancey 1983; Foley 1981b; Vaquero 2008).  For example, the excavations at the Middle Palaeolithic cave occupation of Abric Romaní near Barcelona in Spain are interpreted by their excavators as a series of superimposed palimpsests that include multiple occupation events and there is a concern that approaches that see each level as a discrete contemporaneous floor will distort an understanding of both the temporal and the spatial organization of each layer (Vallverdú et al 2005; Vaquero 2008; Vaquero and Pastó 2001).

Settlements, camps and other occupation sites

The terms “settlement,” “occupation,” “camp” and various other related terms can be used rather sweepingly.   “Occupation” is used to indicate that an area was visited and used by human groups who left evidence of their visit or visits behind.  A “settlement” is defined as any evidence of an occupation that endured for weeks or months – a sufficiently substantial presence to enable discussions about potential spatial organization and structural features.  “Camp” indicates a brief occupation, sometimes used for a single event, sometimes for a specific purpose, usually confined to a small scatter of artefacts with minimal features.  The terms are by no means exhaustive and other descriptive terms will be applied and explained when sites do not fit into any of these categories.  These definitions are practical descriptive tools and do not attempt to capture how sites were experienced.

Rangeland

Land on which native grasses and shrubs grow, and are suitable for grazing or browsing by domestic herds.

Risk

Risk is defined her using Knight’s classic 1921 distinction between risk and uncertainty in which risk is a situation where the outcome of a given situation is unknown but an informed decision can be made based on knowledge and information. Risk and uncertainty require that decisions be made, and these involve the application of probability.  Probability is the data used to decide whether a decision is more or less likely to succeed than any other action also being contemplated, and is a way of measuring risk (Bennett 1998).

Risk management

The economic, social and technological mechanisms put into place in order to minimize the impact of fluctuation and occasionally unpredictable levels of risk.

Ritual, Ideology and Religion

Ritual is defined throughout as the material expression of repeated actions carried out in support of ideology and religion.  Rites of passage are defined as the ceremonies and activities surrounding important transitions that occur through the lives of individuals.  These may or may not take place in or around religious monuments, which are structures designed to enable the performance of ritual activities.  Ritual is an activity that formalizes and reinforces beliefs, ideologies, rules and obligations (Rappaport 1999), and acts as an information flow between the natural and transcendental (Robbins 2001, p.599), serving as a formalizing bridge between ideas and livelihoods.

Social Complexity

Social complexity is defined as internal organization and institutions that lead to social stratification, and may be based on kinship/ancestral, political, and/or religious authority.  It is suggested that defining characteristics of social complexity might be status visible in the uneven distribution of symbolic resources (in the form of elites or leadership); elements of heterarchy; elaborate religious practices requiring organization, labour and ongoing mediation and management; increasingly complex relationships with other members within and beyond the community; storage of surplus; indications of intensified trade/exchange networks; signs of territorial legitimation; craft specialization; increased aggregation; increased sedentism.

Stress

A situation that occurs when the energy needs of a human community fail to be met under existing social and economic regimes.  Stress is an expression of both unpredictable uncertainty and risk.

Subsistence

An economic system that focuses on meeting the needs of a population and enabling it to sustain itself throughout successive years.

Subsistence Strategy

“Subsistence strategies are the set of systems that human groups use to organize themselves, society and economy in a territory with the aim of guaranteeing the survival of their community” (Rosell et al 2012).

Sustainability

The ability to ensure the ongoing productivity of economic outputs and transitions, and the ability to recover from stress and shock, in order to maintain productivity and meet requirements for minimum utility – whist at the same time ensuring that this is not at the detriment of environmental stability.

Trade and exchange

Trade and exchange are treated as the same.  Both involve a transaction between a producer or supplier and a consumer but whereas each trade negotiation is a finite entity, ending when the sale is closed and the purchase completed, exchange may involve longer term and ongoing relationships based on complex relationships in which the exchange of goods helps to define and redefine relationships (Agbe-Davies and Bauer 2010, p.15).  They are not distinguished from each other in this thesis because none of the case studies lends itself to that degree of precision, so following Summerhayes (2015, p.481), trade and exchanged are defined as “the movement of materials or goods between individuals, social groups or organizations.”

Tradition

I follow Spencer in his definition of tradition:  “the notion of tradition, not merely as some immutable practice, but an expression of collective wisdom and accumulated experience that adapts to changing situations” (1998, p.249).

Uncertainty

The condition under which unexpected occurrences are beyond the ability of usual solutions applied by the community to cope, and where the safe and preferred options are unavailable and emergency measures are required.

Vulnerability context

The shocks, trends and seasonal influences that affect people’s ability to support their livelihoods.   Vulnerability refers to circumstances beyond predictable uncertainty, and frequently incorporates high risk situations, like repeated drought.

Wealth / Poverty

The terms wealth and poverty have little value in discussions of prehistoric groups, in spite of the heavy use of both terms in the literature on development economics.  The term “poor” is often used my modern western writers to describe subsistence pastoralists and cultivators who may live marginal lifestyles which prevent them creating and making use of significant surplus, but who may have perfectly sustainable livelihoods which meet or exceed their everyday needs.  The following statement by Livingstone and McPherson (1990) is fairly typical:  “The pastoral people of Africa are among the poorest in the world.  They accumulate limited material possessions and their wealth and security lies in their animals.  Their mobile lifestyle means that very few acquire technical skills or education and consequently only possess knowledge to operate and maintain the most simple of water supply systems.”   In this research I have used “vulnerable” and “unsustainable” to replace “poverty” and have otherwise avoided terms that compare subsistence societies unfavourably with more complex systems.