Spectrum Analysis on Geological Profile: A Case Study of Luzong Area in Anhui China

摘要

In order to further research the geological composition by spectral reflectance characteristics in Luzong area, this study was performed. Using ASD spectraradiometer (FieldSpec-FR), the spectra from multiple profiles were collected, the distance of 100cm from the testing surface was used. The spectral curves were smoothed with the moving average method, and the continuum removal was conducted to highlight features of optical absorbance. Each spectral curve gave the main characteristic composition of the profile, and the spectral curves from different profiles were compared and analyzed, some typical differences could be obtained obviously. All the profiles in the study area saw some similar spectral behavior: there were obsorbing valleys at 900 1450 1900 2200nm, but the number of obsorbing valleys and the bandlength of them were a little different. That is to say, the main structure and component can be obtained by testing spectrum without the help of other professional testing equipment. Using spectral analyst tool of ENVI 5.0 to give a comprehensive score, several minerals obtained high score, some of them clearly inconsistent with the actual were excluded, then the main minerals of the profiles were finalized, and which were consistent with those given by geological materials. For some profiles, the main composition and the relative proportion were also calculated out by the method of linear spectral decomposition, these results gave detailed components of the selected profiles, which had higher value and reliability than the former. Thus the differences between these profiles were also found. Another aim of this paper was to study the method to inversion material compositions and try to provide some usefull references for spectrum analysis. Furthermore, through detailed analysis on the results, it was also found that the measuring distance of 100cm from testing surface was still effective in field spectrum survey, the main structure and component could be obtained by these testing spectra. In order to grasp the nature of things quickly, a larger distance is feasible and necessary, macroscopic geological structure was provided quickly and accurately, which was not affected by local and microscopic interference. Unfortunately, there were some detail information lost, and the testing effect of 10cm from the testing surface will also be analyzed deeply in future.