Quantitative analysis of X-ray microtomography images of geomaterials: Application to volcanic rocks
Quantitative analysis of X-ray microtomography images of geomaterials: Application to volcanic rocks
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地质材料 X 射线显微断层扫描图像的定量分析：在火山岩中的应用
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
M. Polacci
中科院分区：
文献类型：
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作者：
D. Zandomeneghi;M. Voltolini;L. Mancini;F. Brun;D. Dreossi;M. Polacci
X 射线计算机显微断层扫描是岩石微观结构三维分析的绝佳工具。通过数学算法和计算方法采集、可视化和处理数字图像，以识别和测量岩石样本的多个离散特征和成分。在本文中，我们展示了用 X 射线计算机显微断层扫描技术收集的火山岩数字图像，并通过名为 Pore3D 的软件库进行研究，该软件库在 Trieste（意大利）的 Elettra Synchrotron Light 实验室定制实施。使用 Pore3D 软件，我们分析了织物，并量化了四种不同类型火山碎屑的主要成分（囊泡、晶体和玻璃基质）的特征：泡沫浮石、管状浮石、矿渣和“结晶”矿渣。我们确定了这些不同类型火山岩的独特特征。泡沫浮石显示出以各向同性聚集体聚结的囊泡，尤其是朝向样品内部，而矿渣具有低孔隙率和大量的孤立囊泡。在“结晶”熔渣样品中，大部分囊泡分离是由于存在不同类型的晶体，而管浮石在微观尺度上显示出囊泡和晶体的各向异性分布，这也在手样品的尺度上观察到。定量分析和结构信息可以为研究火山岩的喷发过程和起源提供额外的工具。
X-ray computed microtomography is an excellent tool for the three-dimensional analysis of rock microstructure. Digital images are acquired, visualized, and processed to identify and measure several discrete features and constituents of rock samples, by means of mathematical algorithms and computational methods. In this paper, we present digital images of volcanic rocks collected with X-ray computed microtomography techniques and studied by means of a software library, called Pore3D , custom-implemented at the Elettra Synchrotron Light Laboratory of Trieste (Italy). Using the Pore3D software, we analyzed the fabrics and we quantified the characteristics of the main constituents (vesicles, crystals, and glassy matrix) of four different types of pyroclasts: frothy pumice, tube pumice, scoria , and "crystalline" scoria. We identified the distinctive features of these different types of volcanic rocks. The frothy pumices show vesicles that coalesce in isotropic aggregates, especially toward the sample interior, while the scoriae have a low porosity and an abundance of isolated vesicles. In the "crystalline" scoria sample most of the vesicle separation is due to the presence of crystals of different types, while the tube pumice shows an anisotropic distribution of vesicles and crystals at the microscale, as also observed at the scale of the hand sample. Quantitative analysis and textural information may supply an additional tool to investigate the eruptive processes and the origin of volcanic rocks.