The NIR Spectral Characteristics and Meaning of Fault Gouge from Kaxiutata Iron Deposit, Inner Mongolia.

Kaxiutata iron deposit is a skarn type magnetite deposit located in Inner Mongolia, China. There are many faults developed after metallogenic period. In this study, NIR analysis method is adopted to identify the mineral composition of subsurface and surface fault gouge from mining area. Through the characteristic peaks, it is was identified that there are mainly mafic mineral in the subsurface fault gouge and salic minerals in the surface fault gouge, the sand sample for comparison contain both two types of minerals. The result of analysis of all three sets of sample is in accordance with the geological background of the sampling spot. According to this research, due to the main composition of the fault gouge in the mineralization area are clay formed due to the faulting movement and altered minerals formed in early metallogenic period. NIR analysis technology is suitable for this type of sample, to use this technology, we can identify the clay mineral in the fault gouge, and further speculate the composition of protolith of clay，we can also indentify the altered minerals formed in metallogenic period, and provide useful information for study of hydrothermal deposit.

[NIR and XRD analysis of drill-hole samples from Zhamuaobao iron-graphite deposit, Inner Mongolia].

The author analyzed the 4202 drill-hole samples from Zhamuaobao iron-graphite deposit by using near infrared spectroscopy(NIR) and X-ray diffraction(XRD) measuring and testing techniques, and then compared and summarized the results of two kinds of testing technology. The results indicate that some difference of the mineral composition exists among different layers, the lithology from upper to deeper is the clay gravel layer of tertiary and quaternary, mudstone, mica quartz schist, quartz actinolite scarn, skarnization marble, iron ore deposits, graphite deposits and mica quartz schist. The petrogenesis in different depth also shows difference, which may indicate the geological characteristic to some extent. The samples had mainly undergone such processes as oxidization, carbonation, chloritization and skarn alteration. The research results can not only improve the geological feature of the mining area, but also have great importance in ore exploration, mining, mineral processing and so on. What's more, as XRD can provide preliminary information about the mineral composition, NIR can make further judgement on the existence of the minerals. The research integrated the advantages of both NIR and XRD measuring and testing techniques, put forward a method with two kinds of modern testing technology combined with each other, which may improve the accuracy of the mineral composition identification. In the meantime, the NIR will be more wildly used in geography on the basis of mineral spectroscopy.