CATEGORY: branch DEFINITION: The use of geological techniques and methods to archaeological work. It is different from geoarchaeology in that the latter is a subfield of archaeology focusing on the physical context of deposits.
CATEGORY: geology; related field DEFINITION: The study of the physical, chemical, and biological processes and products of the earth; simply, the study of the history of the earth and an understanding of the time scale over which man developed. Geology's aims overlap considerably with those of archaeology, particularly in the prehistoric periods. For example, work on the stratigraphy of the Quaternary to provide a geological chronology for the study of the reconstruction of environmental changes throughout the Quaternary forms an essential background to all archaeology. The palaeontology of fossil hominids and the other animals that lived at the same time is another area in which geology and archaeology overlap. The geological methods of dating such as radiocarbon, palaeomagnetism, and potassium-argon form the basis of most prehistoric chronologies. Geophysical techniques are used for the location of sites and petrology traces the origins of stone implements and inclusions in pottery.
SYNONYMS OR RELATED TERMS: archaeometry, archeometry CATEGORY: technique DEFINITION: Relating or referring to the use of scientific techniques from fields such as chemistry, geology, physics, and other sciences for the analysis of archaeological data.
SYNONYMS OR RELATED TERMS: cross dating CATEGORY: technique DEFINITION: A correlationdating technique that can yield a relative or absolute age or chronology. The basis of cross-dating is the occurrence of finds in association. The assumption is that a particular type of artifact, for example a type of sword, when found in an undated context will bear a similar date to one found in a dated context, thus enabling the whole of the undated context to be given a chronological value. The method is based on the assumption that typologies evolved at the same rate and in the same way over a wide area or alternatively on assumptions of diffusion. Many of the chronologies constructed before the advent of chronometric dating techniques were based on cross-dating. New techniques such as radiocarbon dating showed some of the links established by cross-dating to be invalid, so the method has become somewhat discredited. However, its use is still helpful where recognizable products of dateable manufacture are found in undated contexts with no possibility of using a chronometric dating technique. So in the absence of geochronology, two cultural groups can only be proved contemporary by the discovery of links between them. If in culture A an object produced by culture B is found, A must be contemporary with, or later than, B. The term cross-dating ought strictly to be used only when an object of culture A is also found in proved association with culture B, when overlap of at least part of the time span of each is proved. Items having an established date, such as dated coins or buildings, or ceramics of known manufacture are most often used. By itself, a cross-dated chronology does not give absolute dates, but it may be calibrated by reference to other dating methods. A type of cross-dating has always been used in geology and stratigraphical sequences are often correlated by the assemblages of fossils they contain; this is known as biostratigraphy. The archaeological versions of cross-dating may have been developed directly out of the geological method and may have been based on a false analogy between biological fossils and archaeological artifacts.
SYNONYMS OR RELATED TERMS: depositional process CATEGORY: geology; term DEFINITION: Any of the various processes by which artifacts move from active use to an archaeologicalcontext, such as loss, disposal, abandonment, burial, etc. It is the laying, placing, or throwing down of any material. In geology, it is the constructive process of accumulation into beds, veins, or irregular masses of any kind of loose, solid rockmaterial by any kind of natural agent (wind, water, ice). The transformation of materials from a systemic to an archaeologicalcontext are directly responsible for the accumulation of archaeological sites and they constitute the dominant factor in forming the archaeological record. Deposition is the last stage of behavioral processes, in which artifacts are discarded.
doctrine of uniformitarianism
CATEGORY: geology DEFINITION: A theory that asserts that the processes now modifying the earth's surface are the same processes from all geological past. This principle provided the cornerstone of modern geology.
CATEGORY: related field DEFINITION: The study of entire assemblages of living organisms and their physical milieus, which together constitute an integrated system. In archaeology, ecology seeks to reconstruct the past environment of man and his impact upon it. The term encompasses the relationship of plants and animals with their environment -- climate, geology, soils, vegetation, other animals, man-made structures. Environmental archaeology is concerned with the ecology of man, but also with the ecology of other animals and plants living in the same environment.
CATEGORY: branch DEFINITION: A subfield of archaeology which is the study of the environment in archaeological contexts. It includes not only the study of past flora (pollen analysis, palaeobotany, palaeoethnobotany, archaeobotany), and fauna (archaeozoology), but also that of insects (insect analysis), fish (fish bone analysis), and snail shells (molluscan analysis). All are studied in an attempt to recover the total environment of a past society and to understand man's impact on, and changes to, that environment. It is a field in which interdisciplinary research, involving archaeologists and natural scientists. Many disciplines are involved in this study: climatology, Quaternarygeology, soilscience, palaeobotany, zoology, and human biology.
CATEGORY: related field DEFINITION: A branch of geology (or geography) concerned with the form and development of the landscapes. It includes specializations such as sedimentology. Cultural remains are part of landscapes of the past.
CATEGORY: related field DEFINITION: The study of the physical properties of the earth -- structure, composition, and development -- such as magnetism, radioactivity, vulcanism, etc. Its applications to archaeology have been to provide dating methods (geochronology) and techniques for exploration (magnetometer and resistivity survey). Some dating techniques, e.g. palaeomagnetism, are based on geophysical properties of the earth. It is a subdiscipline of both geology and physics.
CATEGORY: term DEFINITION: Archaeological cultures or strata that have the same relationship to one another but are not necessarily contemporaneous. Objects are homotaxial if they appear in the same relative position in different sequences. The assumption that they are therefore contemporary is usually valid in geology, with its enormous time spans, but certainly not in archaeology, where time lag must be allowed for.
SYNONYMS OR RELATED TERMS: horizon style CATEGORY: term; artifact DEFINITION: Any artifact, art style, or other cultural trait that has extensive geographical distribution but a limited time span. The term, in anthropology, refers to the spread of certain levels of cultural development and, in geology, the layers of natural features in a region; in soilscience a horizon is a layer formed in a soil profile by soil-forming processes. The main meaning, however, refers to a phase, characterized by a particular artifact or artistic style that is introduced to a wide area and which may cross cultural boundaries. Provided that these 'horizon markers' were diffused rapidly and remained in use for only a short time, the local regional cultures in which they occur will be roughly contemporary. The term is less commonly used now that chronometric dating techniques allow accurate local chronologies to be built. Examples of art styles which fulfill these conditions is called a 'horizon style' -- such as Tiahuanaco or Chavín.
Lyell, Sir Charles (1797-1875)
CATEGORY: person DEFINITION: Scottish geologist largely responsible for the general acceptance of the view that all features of the Earth's surface are produced by physical, chemical, and biological processes over long periods of geological time (uniformitarianism). Lyell's achievements laid the foundations for evolutionary biology as well as for an understanding of the Earth's development. His work had a bearing on the development of archaeology at two points. His Principles of Geology" (1830-1833) established the view that the earth had been in existence for very much longer than the 6000 years allowed by the biblical chronology and laid open the way for the later acceptance of the antiquity of man. In 1859 publication of Darwin's "Origin of Species" gave new impetus to Lyell's work. Lyell's "The Geological Evidence of the Antiquity of Man" (1863) tentatively accepted evolution by natural selection."
CATEGORY: site DEFINITION: Palaeolithicsite in Oita Prefecture, Japan, where a date of 4000,000 bp was claimed based on geology and tool comparisons with Zhoukoudian. A few hundred tools, mostly of quartzite, were recovered from a secondary deposit on a marine terrace, including hand axes, scrapers, and flakes. A date of only 70,000 bp is accepted by many archaeologists.
CATEGORY: technique DEFINITION: The study and interpretation of the stratification of rocks, sediments, soils, or cultural debris, based on the principle that the lowest layer is the oldest and the uppermost in the youngest -- a major tool in establishing a relative dating sequence. The sequence of deposition can be assessed by a study of the relationships of different layers. Dateable artifacts found within layers, and layers or structures which are themselves dateable, can be used to date parts of stratigraphic sequences. An archaeologist has to master the skill to recognize it -- to distinguish one deposit from another by its color, texture, smell, or contents; to understand it -- to explain how each layercame to be added, whether by natural accumulation, deliberate fill, or collapse of higher-standing buildings; and to record it in measured drawings of the section. There can be problems where a feature filled with one type of material cuts into layers of the same material. Unless the later feature is recognized, objects of two different phases may appear to be stratified together. The underlying principles are: law of superposition, law of cross-cutting relationships, included fragments, and correlation by fossil inclusions. The stratigraphy principle was adopted from geology and is the basis of reconstructing the history of an archaeological site.
SYNONYMS OR RELATED TERMS: boulder clay CATEGORY: geology DEFINITION: An aggregate of material -- unsorted soil consisting of sand, gravel, clay, and unsorted stones, and deposited directly by a glacier or ice sheet. All grades of particle size may be found. Till is sometimes called boulder clay because it is composed of clay, boulders of intermediate sizes, or a mixture of these. Ice does not sort the material it carries and the range of particle sizes, as well as the range of rock types, depends on the geology over which the ice-sheet or glacier has flowed. There are two types of till, basal and ablation. Basal till is that which was carried in the base of the glacier and commonly set under it. Ablation till is that which was carried on or near the surface of the glacier and came down as the glacier melted.
SYNONYMS OR RELATED TERMS: fossil directeur CATEGORY: artifact DEFINITION: A tool characteristic of a particular archaeological era" a dated concept borrowed from geology. A particular artifactform used to define a specific period or culture such as an Acheulian handax; a specific artifact which serves to represent the taxon of which it is a member. Such an artifact would have a wide distribution in space but a restricted one in time. Its value is for correlating cultural sequences over large areas as in cross-dating. In archaeology the time taken for a type to spread by diffusion must be allowed for and if possible calculated from outside evidence."
SYNONYMS OR RELATED TERMS: uniformitarianism CATEGORY: geology DEFINITION: A fundamental philosophy of geologic science, the principle that the earth was formed by the same natural geological processes that are still going on today. This principle -- that existing processes acting in the same manner and with essentially the same intensity as at present are sufficient to account for all geologic change -- provided the cornerstone of modern geology. William Whewell introduced the term in 1832.
United States Geologic Survey
SYNONYMS OR RELATED TERMS: USGS CATEGORY: term; geology DEFINITION: The government agency charged with the recording and dissemination of information related to the geology of the United States and its holdings.