Two mechanisms of microbial carbonate precipitation
Two mechanisms of microbial carbonate precipitation
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微生物碳酸盐沉淀的两种机制
DOI：
10.1007/bf00600505
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发表时间：
1975
影响因子：
--
通讯作者：
J. Deelman
中科院分区：
文献类型：
--
作者：
J. Deelman
众所周知，在黄土土壤上形成的水坑在干燥后会破裂[1]。这样形成的不规则的碟状凹片面积可达100平方厘米，厚度从L米到L厘米(图1a)。它们是由沉积作用形成的；它们的上层细层比其他层收缩得更快，碎片从下面的土壤中剥离。我拿了一些易碎、柔软的面包屑，放在大约1/2米高、70厘米96的小篝火上焚烧，喂了大约4个小时的木头。我们得到了坚硬的碟状面包屑，只有用手才能很难打碎。这些碎屑的摩尔硬度在3到5之间，吸水率在8%到25%之间，断裂模数在30到60公斤/厘米2之间。现代关于燃烧粘土的数据在50到220公斤/厘米2之间。我认为，在篝火中意外焚烧的碟状碎片可能给史前人类一个想法，即可以通过手工塑造某些粘土并燃烧来制作陶瓷盘子
Puddles formed on loess soil are known to fissure up on drying [1]. The irregular, dish-like, concave pieces thus formed may reach a 100cm 2 area and are from l m m to l c m thick (Fig. 1 a). They are formed by sedimentation; their upper fine layer contracts more quickly than the rest and the pieces break away from the soil beneath. I took some such fragile, soft crumbs and burned them under small bonfires, about 1/2 m high and 70 cm 96 which were fed wood for about 4 hours. We obtained hard, dish-like crumbs which could be broken by hand only with difficulty. These crumbs have a Mohr hardness between 3 and 5, a waterabsorbing capacity between 8 and 25%, and a modulus of rupture between 30 and 60 kg/cm 2. Modern data on burned fire clay range from 50 to 220 kg/cm 2. I propose that dish-like pieces burned accidentally in bonfires may have given to prehistoric man the idea that ceramic dishes can be made by moulding certain clays by hand and burning