Bauxite samples from deposits in northern Saudi Arabia were identified in the laboratory using spectral reflectance measurements (at 0.3–2.5 μm) and X-ray diffraction (XRD). The XRD results revealed that the bauxite deposits are composed mainly of goethite, gibbsite, and boehmite with small amounts of kaolinite, hematite, and quartz. The bauxite spectra revealed the presence of significant iron oxides (at 0.5 and 0.87 μm) accompanied by water (at 1.4 and 1.9 μm) and aluminum hydroxide (at 2.2 μm). The convolved Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) spectra of the bauxite samples were characterized by an aluminum hydroxide feature in ASTER band 6 (at 2.2 μm). The results demonstrated that principal components analysis band PC2 is the best component for delineating the bauxite deposits. Fractional abundances of bauxite were derived by using a matched-filtering method. This study demonstrates the applicability of reflectance spectroscopy and ASTER data to provide spectral information for distinguishing economically important minerals from visible and near-infrared and shortwave-infrared spectra in arid and semiarid environments such as in Saudi Arabia.

使用光谱反射率测量（0.3–2.5μm）和X射线衍射（XRD）在实验室中鉴定了沙特阿拉伯北部矿床的铝土矿样品。X射线衍射结果表明，铝土矿床主要由针铁矿，菱镁矿和勃姆石组成，少量的高岭石，赤铁矿和石英组成。铝土矿光谱显示存在大量的氧化铁（分别为0.5和0.87μm），以及水（分别为1.4和1.9μm）和氢氧化铝（2.2μm）。铝土矿样品的卷积高级星载热发射和反射辐射计（ASTER）光谱的特征是ASTER 6波段（2.2μm）具有氢氧化铝特征。结果表明，主成分分析带PC2是描绘铝土矿沉积物的最佳成分。铝土矿的分数丰度是使用匹配过滤法得出的。这项研究证明了反射光谱法和ASTER数据的适用性，可提供光谱信息，以区分诸如沙特阿拉伯等干旱和半干旱环境中的可见，近红外和短波红外光谱中的重要经济矿物。