The rare earth elements and yttrium (REY) of the K2 coal from the Moxinpo mine, Chongqing, were determined using inductively coupled plasma mass spectrometry (ICP-MS). The results show that REY are enriched in the K2 coal, with the average content up to 462 lg/g, much higher than average values of most coals in the world. The REY distribution patterns indicate that the light REY is enriched and show a well-pronounced Eu minimum. The fractionation of individual light-REY is higher than that of the heavy-REY. The REY distribution through the K2 coal seam shows that the top and bottom portion of the coal seam have a lower content of REY than the middle portion. Goyazite and rhabdophane were identified with a scanning electron microscope equipped with an energy-dispersed X-ray spectrometer (SEM-EDX). The REY distributions through the coal seam, SEM-EDX data and the correlation analysis between ash yields and the concentrations have revealed that the REY mainly occurs in the organic matter. The K2 coal is a potential rare-metal resource due to its high REY contents, and the coal ash could be regarded as a new and promising raw material for recovery of REY as a by-product.

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Frequency domain helicopter-borne electromagnetic survey is still in the stage of research and test stage in China. Due to the lack of effective means of data processing, further application and development of this technology are limited. This paper presents briefly the Marquardt's algorithm, and the successful application of it to the processing of airborne electromagnetic data in the frequency domain. And several key technologies such as Jacobian matrix calculation, the initial model assignment, the shape model and physical properties model inversion are discussed. Finally, the method has been used on some theoretical models and field data to verify its effectiveness and correctness. This work has filled the gap of this technology at home and attained good application result.

The iron belt of northern Hebei and Shanxi provinces to western Liaoning province locates in great geological conditions and hosts various types iron mines, so the prospecting potential is huge. The found iron ore with industrial value have sedimentary metamorphic mines with large scale, and followed by magmatic, sedimentary, and contact-metasomatic ore deposits, etc. The iron mineralization of different types is great affiliated with the geotectonic environment of different geological periods, sedimentation, magmatic conditions, that behaviors different mineralization types corresponding to different geological periods in time, behaviors different iron mining area corresponding to different structural location in the space, consists of the iron metallogenic series coupled to the different time and the different genetic types in North China. Based on the analysis to the distribution regularity, ore-controlling factors and metallogenic series of iron mine, we deeped the regional ore-controlling geological condition and metallogenic regularity of iron ore, provided important reference information for regional exploration.

The inversion stability of geological data can be enhanced by increasing the number of observation data or improving the accuracy of it. For the purpose of increasing the input parameters, the joint inversion algorithm based on Marquette’s method is introduced to the helicopter-borne electromagnetic system. Since double parameters of both the horizontal coplanar and vertical coaxial coils were taken into account, the stability of the inversion process is greatly improved. In fact, the joint inversion algorithm not only enhances the inversion’s stability, but also overcomes the limitation of the inversion with each single device in order to make the result closer to the real resistivity characteristics