کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4726133 1640009 2010 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Thermal infrared spectroscopy on feldspars — Successes, limitations and their implications for remote sensing
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
Thermal infrared spectroscopy on feldspars — Successes, limitations and their implications for remote sensing
چکیده انگلیسی

Minerals of the feldspar group are the most common on earth. Feldspars are economically important in two ways: either as industrial minerals or as a vector-to-ore for mineral deposits. In order to use feldspars for classifying rock compositions or metasomatic conditions during rock alteration events, there is a need for analytical methods to identify and classify feldspars.Traditionally, feldspar composition and structure have been investigated using methods such as optical microscopy, electron microprobe analysis (EMPA), cathodoluminescence and X-ray diffraction (XRD) analysis. In this paper infrared techniques (0.7–25 μm)) are reviewed in detail and investigated in how far some of the traditional analytical methods can be replaced by infrared spectroscopy. Successes as well as limitations of infrared approaches are highlighted and existing work is scrutinized in terms of its applicability to remote sensing techniques.Even though numerous studies on mid-infrared (MIR) spectroscopy of feldspars exist, their results often cannot be directly related to remote sensing applications. Examples are the effects of feldspar twinning, exsolution textures and structural state on infrared spectra. The applicability of the results to emission remote sensing requires further research. It has been shown that linear unmixing of laboratory infrared spectra of rocks works fairly well. Detection limits for feldspar are around 5% and plagioclase composition can be determined within error margins of ± 4% anorthite component. Infrared spectroscopy can, however, not detect compositional zonation or different generations of feldspars. Infrared spectra represent the current average plagioclase and average alkali feldspar composition in the sample.With several new airborne instruments under development, it is opportune to focus upcoming research efforts on developing standardized processing techniques and spectral feldspar indices for thermal infrared imagery. Commercially interesting products include numbers of feldspars species, plagioclase and alkali feldspar composition, their structural state and relative or semi-quantitative abundance in the rocks.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Earth-Science Reviews - Volume 103, Issues 1–2, November 2010, Pages 60–70
نویسندگان
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