Geologic ranking factors

Another proof of the importance of temperature is the fact that there is often a strict relationship between the run of isovols and the run of isotherms in deep profiles, both being influenced no doubt by the varying thermal conductivity of the different rocks. The strong influence of temperature on the rank of coal is obvious in the case of contact-metamorphic coals, whose rank increases distinctly when approaching the intrusive body. Apart from these geological observations, all experiments on artificial coalification have shown that temperature is the decisive factor in the coalification process. Thermodynamic and reaction kinetic considerations (9) also support this opinion. 

The Louisiana sites so far ranked using draft guidance for data input to the model have not scored high, compared to many other sites in the nation. In general, two factors account for the relatively low scores (1) low population density (except in one case) and (2) subsurface geology and hydrology that tends to minimize potential for groundwater contamination. 

This general review of factors influencing major, minor, and trace element variations in U.S. coals provides an interpretation of coal inorganic elemental data found in the literature. Variations due to ash-related, rank-related, geochemical, and geological factors are discussed. 

Lv, Y, Tang, D., Xu, H. Luo, H. (2012) Production characteristics and the key factors in high-rank coalbed methane fields A case study on the Fanzhuang Block, Southern Qinshui Basin, China. International Journal of Coal Geology. 

Whereas the degree of coaliflcation generally determines the rank of the coal, the process is not a series of regular, or straightforward, chemical changes. Indeed, complexity is the norm insofar as the metamorphosis of the plant debris relies not only on geological time but also on other physical factors, such as temperature and pressure. Thus, the occurrence of a multitude of different and complex chemical reactions (no matter how simple they appear on paper or how simply they occur in laboratory simulations) is inherent in the coaliflcation process. 

Outside of the conducted research there are some issues such as the types of landslides, the age of initiation and relationship with ruptural structures of different ranks, engineering geology conditions. We realize fully that, of course, these factors and characteristics are very important for making predictive assessment of slope stability. It is also important to have record of earthquakes... 

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