火成岩光谱吸收深度与矿物组分黑云母含量关系研究

摘要

岩石的矿物组成成分是影响其反射光谱特征的主要因素之一，是产生各类岩石特征谱带的重要原因。本文选择美国喷气推进实验室提供的岩石样本（包括组成岩石样本的各类矿物百分含量和用 Analytical Spectral Devices （ASD）地物光谱仪测得0．35～2．50μm 波长范围内岩石样本光谱反射率）、岩石所包含的各类矿物的光谱反射率为基础数据，根据岩石和所含矿物的光谱线性混合模型，首先进行了岩石及其矿物成分线性混合模拟实验，实验结果表明基于线性混合光谱理论的岩石矿物模拟模型能够较好的模拟岩石光谱曲线，并且能够保留各个矿物组分的吸收特征。然后从火成岩的岩石光谱中选出含有黑云母矿物的八个样本，研究岩石样本中黑云母含量及其在2．332μm 处反射光谱吸收深度的特征，用线性和非线性等多种常用统计模型拟合了岩石光谱吸收深度与矿物组分黑云母含量之间的响应关系，最后本文将增长型（Growth）和指数曲线型（Exponential）两个模型相结合获得新的拟合模型，利用该模型拟合了岩石光谱吸收深度与矿物组分黑云母含量之间的统计响应关系，拟合结果表明二者的相关系数达到0．9984，标准偏差为0．572，虽然利用 Growth 和 Exponential 模型拟合的标准偏差小于两个模型结合后的新模型拟合的标准偏差，但新模型的相关系数有了显著提高，这说明新模型拟合效果更接近样本的实测值。%The mineral composition of rock is one of the main factors affecting the spectral reflectance charac-teristics,and it’s an important reason for generating various rock characteristic spectra.This study choose the rock samples provided by Jet Propulsion Laboratory (JPL)(including all kinds of mineral percentage of rocks, and spectral reflectances range from 0.35 to 2.50 μm wavelength measured by ASD spectrometer),and the va-rious types of mineral spectral reflectances contained within the rocks are the essential data.Using the spectral linear mixture model of rocks and their minerals,firstly,a simulation study on the mixture of rock and mineral composition is achieved,the experimental results indicate that rock spectral curves using the model which based on the theory of the linear mixture are able to simulate better and preserve the absorption characteristics of various mineral components well.Then,8 samples which contain biotite mineral are picked from the rock spectra of igneous,biotite contents and the absorption depth characteristics of spectral reflection at 2.332 μm, furthermore,a variety of linear and nonlinear normal statistical models are used to fit the relationship between the depth of absorption spectra and the content of the mineral composition of biotite,finally,a new simulation model is build up with the Growth and the Exponential curve model,and a statistical response relationship be-tween the spectral absorption depth and the rock mineral contents is simulated by using the new model,the fit-ting results show that the correlation coefficient reaches 0.998 4 and the standard deviation is 0.572,although the standard deviation using Growth and Exponential model is less than the two model combined with the new model fitting the standard deviation,the correlation coefficient of the new model had significantly increased, which suggesting that the new model fitting effect is closer to the measured values of samples,it proves that the simulation results of new model is closer to the measured value.