[Terrapreta] Pottery Shards and Terra Preta

[Robert Klein]

Hi lou

As I described in earlier postings, I have every reason to suspect that the terra preta biochar was manufactured by the building of tightly packed corn stover stacks with earthen walls created by the brick like root balls.  All very feasible within the  labor availability.

Check my blog for postings on this in June and July

http://globalwarming-arclein.blogspot.com

In order to start and maintain the burn it is necessary to carry a charge of coals onto the top of the stack and to tip in into the center and then cover same.  The only way available would be to use a sun dried clay platter that was unlikely to be fired and was also likely made from poor grades of clay.  This easily explains the buildup of 'pottery ' in the soils.  It would degrade fairly quickly since it would be very weak.

The coals would drive a chimney through the stack and maintain a burn that would largely consume the produced volatiles in the chimney.  The plate would be placed on top of the coals and be covered with earth to complete the shell.  Similar but cruder methods are used today with wood to produce charcoal in Africa.  There the packing is poor but the wood cutting is very efficient thanks to modern tools.


arclein

----- Original Message ----
From: lou gold <lou.gold at gmail.com>
To: Kevin Chisholm <kchisholm at ca.inter.net>
Cc: Terrapreta preta <terrapreta at bioenergylists.org>
Sent: Monday, December 10, 2007 12:19:17 PM
Subject: Re: [Terrapreta] Pottery Shards and Terra Preta


Kevin,

I don't know if you watched the BBC video, "The Secret of El Dorado"? 
It shows the pottery dramatically, in layers deep into the soil. 
http://video.google.com/videoplay?docid=-2809044795781727003&q=secret+of+el+dorado&total=21&start=0&num=10&so=0&type=search&plindex=0

The pottery shards are suggestive to me. I speculate that the earth kilns used for making the pottery (loaded with lots of broken pieces from pottery making) became middens for human and organic wastes. Later as the whole "stew" ripen into TP, it could have been transfered to the fields and also be useful structurally for creating raised beds and preventing erosion under the heavy rains.


What do you think?

lou





On Dec 10, 2007 5:09 PM, Kevin Chisholm <kchisholm at ca.inter.net> wrote:

Some people hold that pottery shards are an important aspect to the
working of Terra Preta, (TP) but others feel that the presence of
pottery shards in Amazonian Dark Earths (ADE) is incidental to the
performance of the TP.


Is it possible that the Researchers looked for the presence of pottery
shards as a way of proving human involvement, and did most of their work
on TP soils that had a human involvement?

Pottery was a big art of Brazilian Indian Culture, but other Ancient

Cultures did not have, or made very little use, of pottery. Are tehre
any "black earth" deposits outside "pottery cultures" that are
acknowledged as being the equivalent to TP?

Is it possible that there are many man made TP soils to which no shards

were added?

What is the nature of the shards found in TP? Are they like a crushed
grog, where it is obvious that effort had been expended breaking the
pottery to relatively small pieces, OR, is shard size and shape such

that it suggests broken pottery items were simply discarded?

Are the shards of a nature in size and completeness that they could be
re-assembled to reveal the size and shape of the original pottery items?


Is there any evidence to suggest that pottery shards were indeed added
on purpose, in contrast to merely being disposed of an non-functional items?

Is there any evidence to show that TP WITH pottery shards  works better

than TP WITHOUT shards?

Is there any evidence that shards of one range of sizes and composition
and degree of firing give better results in TP than another?

Can anyone think of other reasons why pottery shards would be a valuable

addition to TP?

Can anyone think of reasons why pottery shards would not make any
difference?

Any facts, comments and observations would be both enlightening and
appreciated.

Best wishes,


Kevin


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