Red_desert

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Sounds like could be name of place in Don's area. If there is gold prospecting, might be.
you talking to me red desert or Brazilian?

Think it was you but Brazilian answered, doesn't seem to be Don's area.
 

Red_desert

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I was wondering about pieces you identified as being connected to sites of older culture. I tried clearing one plain type. See if it helped visibility any.
In fact, this is a microscopic detail from the surface of one of the pottery shards. It shows some of the raw materials used to produce the pottery.

Archaeologists study shards. would be neat if some of those pieces could be dated.
 

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BrazilianExplorer

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Archaeologists study shards. would be neat if some of those pieces could be dated.
Archaeologists study shards. would be neat if some of those pieces could be dated.
This is one of my current interests and in fact they can be dated by several techniques including thermoluminescence, radiocarbon, maybe even by reydroxylation, etc.
 

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Red_desert

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Archaeologists study shards. would be neat if some of those pieces could be dated.
Archaeologists study shards. would be neat if some of those pieces could be dated.
This is one of my current interests and in fact they can be dated by several techniques including thermoluminescence, radiocarbon, maybe even by reydroxylation, etc.

Never thought about... thermoluminescence, maybe thermal imaging camera.
 

Red_desert

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Tried searching, here is link.


7 Conclusions​

Thermoluminescence (TL), performed in a scanning electron microscope, is a valuable tool for the characterization of point defects in semi-insulating bulk crystals and epitaxial layers. We demonstrated spatially resolved defect analyses down to a few microns for AlN and GaN. By investigating the sample excitation process, we have shown that for small beam currents in the range of a few pascals and excitation times in the order of seconds, the TL probe volume is mainly determined by the primary electron scattering volume. This allows a local defect characterization on a microscopic scale of a few microns. However, we found that strong CL yield may impair the spatial resolution due to intense CL, which causes photoexcitation of the specimen.

In addition, we have extracted some of the trap parameters from our TL curves and discussed the results. Also, we applied some related methods of TL to our AlN crystals, such as using different temperatures for sample excitation. This allowed us to identify a trap with a thermal capture barrier whose population is prevented at low temperatures. By using a CCD camera and a monochromator, we also performed spectrally resolved TL measurements in a SEM. This enables investigations of the radiative recombination channels, which are active during TL emission.
 

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BrazilianExplorer

Jr. Member
Jan 31, 2016
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Tried searching, here is link.


7 Conclusions​

Thermoluminescence (TL), performed in a scanning electron microscope, is a valuable tool for the characterization of point defects in semi-insulating bulk crystals and epitaxial layers. We demonstrated spatially resolved defect analyses down to a few microns for AlN and GaN. By investigating the sample excitation process, we have shown that for small beam currents in the range of a few pascals and excitation times in the order of seconds, the TL probe volume is mainly determined by the primary electron scattering volume. This allows a local defect characterization on a microscopic scale of a few microns. However, we found that strong CL yield may impair the spatial resolution due to intense CL, which causes photoexcitation of the specimen.

In addition, we have extracted some of the trap parameters from our TL curves and discussed the results. Also, we applied some related methods of TL to our AlN crystals, such as using different temperatures for sample excitation. This allowed us to identify a trap with a thermal capture barrier whose population is prevented at low temperatures. By using a CCD camera and a monochromator, we also performed spectrally resolved TL measurements in a SEM. This enables investigations of the radiative recombination channels, which are active during TL emission.
And this one is about the so-called rehydroxylation method:
 

joshuaream

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Late to this post, I don't check this side of the forum as often as I should.

That area of Brazil (Central Brazil and up into the Amazon) has some of the oldest pottery in the Americas. It's likely you have a long range of habitation and use on the site. Manioc/Cassava harvest and processing drove amazing amounts of pottery production.

I remember a fishing trip several hours outside of Manaus where there was a well known camp site called Sambaquis da something that was shell/pottery midden that was probably a mile long and 10-12 feet high the entire length. Parts were higher, and it looked like there was some previous excavations. (Both archaeological, and for use as fill on the boat ramps, and housing pads.)

The utilitarian stuff is hard to pin down without TL testing. The functional style for cooking just didn't change much. Painted, decorative, and ornate styles are a bit easier. The type of points and styles of axes can help, but again it's entirely possible you have a couple thousand years of usage. I'd love to see the points if you have any. Well made points in Brazil tend to be older, then become unifacial to non-existent as they get towards the more recent prehistoric times.
 

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BrazilianExplorer

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Jan 31, 2016
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Late to this post, I don't check this side of the forum as often as I should.

That area of Brazil (Central Brazil and up into the Amazon) has some of the oldest pottery in the Americas. It's likely you have a long range of habitation and use on the site. Manioc/Cassava harvest and processing drove amazing amounts of pottery production.

I remember a fishing trip several hours outside of Manaus where there was a well known camp site called Sambaquis da something that was shell/pottery midden that was probably a mile long and 10-12 feet high the entire length. Parts were higher, and it looked like there was some previous excavations. (Both archaeological, and for use as fill on the boat ramps, and housing pads.)

The utilitarian stuff is hard to pin down without TL testing. The functional style for cooking just didn't change much. Painted, decorative, and ornate styles are a bit easier. The type of points and styles of axes can help, but again it's entirely possible you have a couple thousand years of usage. I'd love to see the points if you have any. Well made points in Brazil tend to be older, then become unifacial to non-existent as they get towards the more recent prehistoric times.

Thanks for your reply and it was not so late since you shared some very important aspects!

You are right that this region has some of the oldest pottery already discovered in America. Despite some of them could in fact be related to manioc/cassava processing, since the region (few km from there) has lots of native parents of this species, it could also be related to oil processing of a native fruit.

I know about Sambaquis from Amazonia and they are in fact incredible. Curiously these fragments that I showed were not painted at all with some figure or motifs, but there are some decorative plastic details in borders. Yes, I found some stone artifacts despite points are not common.
 

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