The ceramic artifacts in archaeological black earth (terra preta) from lower Amazon region, Brazil: Mineralogy
Submitted by Tom Miles on Sun, 2007-01-21 04:05
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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.
Key words: Terra Preta, Black Earth, Archaeological ceramic fragment, Lower Amazon, Phosphates, Mineralogy.
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I had come across a blog
I had come across a blog chat about the paramagnetic forces that may be at work in the sherds found throughout TERRA PRETA alas had equipment malfunction and lost the site address and have not found it yet. But basically I think there is a premise*(1) for the sherds actually being bio-(magnetically?)active. Sort of a radiant regulator for various organisms in living soils.
I do not ascribe to the "whole" bio-dynamic theory (set apart from other organic agri-culture systems by its association with the "spiritual science" of anthroposophy by Steiner)*(3) but I DO accept that there is activity on a molecular scale that we do not and maybe never will fully understand. Thank goodness these activities are pretty benign and I do not have to wait till the scientists understand it all to use it in the garden.
Some of the biodynamics preps have bio-active ceramic particles in them. I have been adding crushed ceramic matter to my compost and microbial brews for a couple years and I turn out 200 lbs of amazing compost every couple of weeks. ... if it makes the microbes happy the soil will be healthier and plants grow with less man-made provisions.
Still I wish that blog would make this list somehow.
*(2) While seven different geophysical methods were applied, the "magnetic survey" reported here was particularly valuable.(searching for ancient hearths in Brazil) Magnetic surveys measure the earth's magnetic field very accurately. Buried ferrous materials, and in some cases, changes in bedrock lithology, produce disturbances in the local magnetic field that can be readily detected by magnetic surveys.(if researchers can find weak magnetic fields to chart sites of interest, microbes may also be sensitive to them for orientation to accomplishing their work... MHO)
*(1) http://www.hager-richter.com/mag.htm
*(2) http://www3.interscience.wiley.com/cgi-bin/abstract/102531616/ABSTRACT?C...
*(3)http://attra.ncat.org/attra-pub/biodynamic.html