CATEGORY: lithics DEFINITION: A steep-edged, often large, domed core with flat based striking platforms, heavily step-flanked around their margins.CATEGORY: technique DEFINITION: Borings taken from the Arctic and Antarctic polar ice caps, containing layers of compacted ice, useful for the reconstruction of paleoenvironments and paleoclimatology and as a method of .A core sample is a roughly cylindrical piece of subsurface material removed by a special drill and brought to the surface for examination.
In a piston corer, a closely fitted piston attached to the end of the lowering cable is installed inside the coring tube.
When the coring tube is driven into the ocean floor, friction exerts a downward pull on the core sample.
The horn itself forms a tight sheath around the core, which is removed for horn working.
Some archaeological sites have large accumulations of horn cores related to a horn-working industry.
CATEGORY: artifact DEFINITION: A steep-edged, often large, domed core with flat based striking platforms, heavily step-flanked around their margins.
Both very large and smaller varieties are found commonly on Pleistocene sites in most areas of Australia and on some mid-Holocene sites and they are considered characteristic of the Australian Core Tool and Scraper tradition.Continuous cores, sometimes taken to the bedrock below, allow the sampling of an ice sheet through its entire history of accumulation.Because there is no melting, the layered structure of the ice preserves a continuous record of snow accumulation and chemistry, air temperature and chemistry, and fallout from volcanic, terrestrial, marine, cosmic, and man-made sources.An object, such as a hand-CATEGORY: tool DEFINITION: A hollow tubelike instrument used to collect samples of soils, pollens, and other materials from below the surface. SYNONYMS OR RELATED TERMS: core tablet CATEGORY: artifact DEFINITION: A roughly round slightly wedge-shaped flake of flint with the remains of flake beds around the outside edge.Such flakes are the product of extending the life of a core that has become uneven or difficult to work but which still has the potential to yield further blades.These changes, suggestive of climatic variation, help to chart the progress of glaciation and, since they can be dated, the technique assists in the establishment of a chronology for the Quaternary. Variations in the ratio of two oxygen isotopes in the , ionium dating, uranium series dating, palaeomagnetism, protactinium/ionium dating) can be used on the carbonate in the shells, absolute dates can be given to the different levels in the core.