Detailed near-infrared study of the ‘water’-related transformations in silcrete upon heat treatment
Detailed near-infrared study of the ‘water’-related transformations in silcrete upon heat treatment
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对热处理后硅混凝土中与“水”相关的转变进行详细的近红外研究
DOI：
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发表时间：
2016
影响因子：
1.4
通讯作者：
K. Nickel
中科院分区：
文献类型：
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作者：
P. Schmidt;C. Lauer;Gerald Buck;C. Miller;K. Nickel
在考古学中，石器热处理是使用火来修改岩石以生产石器的过程。虽然已知最早的热处理案例来自南非，涉及硅结砾岩，一种微晶成土硅质岩，但其热转化仍然知之甚少。我们调查的“水”相关的转换硅结砾岩使用直接透射近红外光谱。我们发现，SiOH在250至450 °C之间明显损失，羟基与H2O反应，其中一部分被困在岩石的结构中。这些水只能在高温下通过热致破裂蒸发，硅结砾岩热处理的最高温度约为500 °C。在250 °C至450 °C之间，根据反应2SiOH → Si-O-Si + H2O形成新的硅氧烷键，预计这将改变岩石的机械性能。硅结砾岩对相对较快的升温速率的耐受性可以通过其孔隙体积和低SiOH含量来解释，从而确保良好的水分蒸发。这些结果揭示了硅结砾岩在热处理过程中发生的过程，并允许更好地了解它所需的参数。
In archaeology, lithic heat treatment is the process of modifying a rock for stone tool production using fire. Although the earliest known cases of heat treatment come from South Africa and involved silcrete, a microcrystalline pedogenic silica rock, its thermal transformations remain poorly understood. We investigate the ‘water’-related transformations in silcrete using direct transmission near-infrared spectroscopy. We found that SiOH is noticeably lost between 250 and 450 °C and hydroxyl reacts with H2O, part of which is trapped in the structure of the rocks. This water can only be evaporated through heat-induced fracturing at high temperatures, imposing maximum temperatures for silcrete heat treatment of approximately 500 °C. Between 250 and 450 °C new siloxane bonds are formed according to the reaction 2SiOH → Si–O–Si + H2O, which can be expected to transform the rock’s mechanical properties. The tolerance of silcrete for relatively fast ramp rates can be explained by its pore volume and low SiOH content, ensuring good water evaporation. These results shed light on the processes taking place in silcrete during heat treatment and allow for a better understanding of the parameters needed for it.
先前未描述的有机残留物揭示了中石器时代的热处理
影响因子：
3.2
作者：
Schmidt;Porraz;Bellot-Gurlet;February;Ligouis;Texier;Parkington;Miller;Nickel;Conard
通讯作者：
Conard