Characterizing clay mineralogy in Lake Towuti, Indonesia, with reflectance spectroscopy
Characterizing clay mineralogy in Lake Towuti, Indonesia, with reflectance spectroscopy
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利用反射光谱表征印度尼西亚托乌提湖的粘土矿物学
DOI：
10.1007/s10933-015-9844-4
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发表时间：
2015
影响因子：
2.1
通讯作者：
S. Bijaksana
中科院分区：
文献类型：
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作者：
A. Weber;J. Russell;T. Goudge;M. Salvatore;J. Mustard;S. Bijaksana
我们测试了使用可见光到近红外（VNIR）反射光谱，以表征粘土矿物的相对丰度从Towuti湖，在印度尼西亚苏拉威西岛的一个大的构造湖沉积物。我们测量了湖泊和河流沉积物的VNIR光谱Towuti湖及其集水区，以确定粘土矿物，适合主要VNIR吸收功能与修改后的高斯模型，以估计这些矿物的相对丰度，并比较这些样品的化学性质，以测试VNIR光谱的实用性，以表征沉积物成分的变化。结果表明，高岭石中的Al-OH（2.21 μm）、绿脱石中的Fe-OH（2.29 μm）、皂石和蛇纹石中的Mg-OH（2.31 μm）和蛇纹石中的Mg-OH（2.34 μm）的振动是引起矿物矿物中的主要原因。这用X射线衍射数据证实。Fe-OH，Al-OH，Mg-OH振动和Fe，Al和Mg浓度的吸收带面积之间的相关性，分别是统计学上显着的，在r = 0.51和r = 0.90之间变化，推断的粘土矿物在湖泊内的空间变化是一致的地质变化的流域。我们的结论是，VNIR光谱是一种有效的方法来表征湖泊沉积物的粘土矿物学，并可用于调查矿物输入湖泊沉积物的变化。
We tested the use of visible to near-infrared (VNIR) reflectance spectroscopy to characterize the relative abundances of clay minerals in sediments from Lake Towuti, a large tectonic lake in Sulawesi, Indonesia. We measured VNIR spectra of lake and river sediments from Lake Towuti and its catchment to identify clay minerals, fit major VNIR absorption features with a modified Gaussian model to estimate relative abundances of these minerals, and compared these absorptions to the samples’ chemistry to test the utility of VNIR spectroscopy to characterize sediment compositional variations. We found that major absorptions are caused by vibrations of Al–OH in kaolinite (2.21 μm), Fe–OH in nontronite (2.29 μm), Mg–OH in saponite and serpentine (2.31 μm), and Mg–OH in serpentine (2.34 μm). This was confirmed with X-ray diffraction data. The correlations between absorption band areas for Fe–OH, Al–OH, and Mg–OH vibrations and Fe, Al and Mg concentrations, respectively, are statistically significant, varying between r = 0.51 and r = 0.90, and spatial variations in inferred clay mineralogy within the lake are consistent with variations in the geology of the catchment. We conclude that VNIR spectroscopy is an effective way to characterize the clay mineralogy of lake sediments, and can be used to investigate changes in mineral inputs to lake deposits.