Thermoluminescence dating of brazilian indigenous ceramics
Slip is a liquid clay suspension of mineral pigments applied to the ceramics before firing.
Cords, textiles, baskets, and corncobs have been rolled over wet clay, both as a decoration and to improve heat dispersion in cooking pots.Two indigenous ceramics fragments, one from Lagoa Queimada (LQ) and another from Barra dos Negros (BN), both sites located on Bahia state (Brazil), were dated by termoluminescence (TL) method.Each fragment was physically prepared and divided into two fractions, one was used for TL measurement and the other for annual dose determination.Pottery is fired ceramics with clay as a component.Ceramics are used for utilitarian cooking vessels, serving and storage vessels, pipes, funerary urns, censers, musical instruments, ceremonial items, masks, toys, sculptures, and a myriad of other art forms.Slips can be applied overall in washes, creating large color fields, often with cloth, or they can be painted in fine detail with brushes.
Yucca leaves, chewed slightly to loosen fibers, make excellent brushes that are still in use today in the American Southwest.
Hohokam potters and their descendents in the American Southwest employed the paddle-and-anvil technique, in which the interior clay wall of a pot was supported by an anvil, while the exterior was beaten with a paddle, smoothing the surface.
In precontact South America, ceramics were mass-produced using molds.
In coiling, the clay is rolled into a long, thin strands that are coiled upon each other to build up the shape of the pottery.
While the potter builds the coils up, she also blends them together until there was no trace of the ropes of clay entwined to form the pot, no deviation in the thickness of the walls, and therefore no weaknesses.
Finally, the ceramics surface is often polished with smooth stones.