BioEnergy Lists: BioChar (or Terra Preta)

The ceramic artifacts in archaeological black earth (terra preta) from lower Amazon region, Brazil: Mineralogy
Marcondes Lima da Costa, Dirse Clara Kern, Alice Helena Eleotério Pinto, Jorge Raimundo da Trindade Souza, Acta Amazonica. vol.34 no.2 Manaus 2004

ABSTRACT

Several archaeological black earth (ABE) sites occur in the Amazon region. They contain fragments of ceramic artifacts, which are very important for the archaeological purpose. In order to improve the archaeological study in the region we carried out a detailed mineralogical and chemical study of the fragments of ceramic artifacts found in the two ABE sites of Cachoeira-Porteira, in the Lower Amazon Region. Their ceramics comprise the following tempers: cauixi, cariapé, sand, sand +feldspars, crushed ceramic and so on and are composed of quartz, clay equivalent material (mainly burned kaolinite), feldspars, hematite, goethite, maghemite, phosphates, anatase, and minerals of Mn and Ba. Cauixi and cariapé, siliceous organic compounds, were found too. The mineralogical composition and the morphology of their grains indicate a saprolite (clayey material rich on quartz) derived from fine-grained felsic igneous rocks or sedimentary rocks as source material for ceramic artifacts, where silica-rich components such cauixi, cariapé and/or sand (feldspar and rock fragments) were intentionally added to them. The high content of (Al,Fe)-phosphates, amorphous to low crystalline, must be product of the contact between the clayey matrix of pottery wall and the hot aqueous solution formed during the daily cooking of animal foods (main source of phosphor). The phosphate crystallization took place during the discharge of the potteries put together with waste of organic material from animal and vegetal origin, and leaving to the formation of the ABE-soil profile.

Terra Preta - Wikipedia

Map of the Terra Preta Occurrences in Brazil
University of Beyreuth, Germany

Terra Preta Arqueológica (TPA)
Dra. Dirse Clara Kern, Museu Paraense Emílio Goeldi (MPEG),Belem, Para,Brasil

Este web site é uma iniciativa da linha
de pesquisa Geoarqueologia da Coordenação de Ciências da Terra e Ecologia do Museu Paraense Emílio Goeldi (MPEG), sob a responsabilidade da Dra. Dirse Clara Kern.

Tem como finalidade divulgar os trabalhos sobre Terra Preta Arqueológica (TPA) e servir de ponte de agregação para os projetos desenvolvidos e em desenvolvimento sobre o assunto.

Terra Preta Homepage, Dark earths, Red Indian black earth
University of Bayreuth, Bayreuth, Germany 2002

Terra Preta (do indio) is a black earth-like anthropogenic soil with enhanced fertility due to high levels of soil organic matter (SOM) and nutrients such as nitrogen, phosphorus, potassium, and calcium embedded in a landscape of infertile soils (see soil profiles below). Terra Preta soils occur in small patches averaging 20 ha, but 350 ha sites have also been reported. These partly over 2000 years old man made soils occur in the Brazilian Amazon basin and other regions of South America such as Ecuador and Peru but also in Western Africa (Benin, Liberia) and in the savannas of South Africa. Terra Preta soils are very popularby the local farmers and are used especially to produce cash crops such as papaya and mango, which grow about three times as rapid as on surrounding infertile soils.