) one of the important characteristics of substance, which reflects its structure stability, the strength of bonds between its separate elements, structure defects availability (dislocations in crystalline structure of mineral grains, pores, microcracks) and its density. Hence, every alteration of external conditions of rock and other material formation and transformation, must evoke a change in the Debye characteristic temperature.The Debye theory gives the connection between heat capacity of poly-atomic solid and its elastic coefficient and also possibility to calculate the characteristic temperature (, K) on the basis of data density (
) and velocities of longitudinal (Vp) and transversal (Vs1, Vs2) ultrasonic waves in the solid (Dergachov, Starostin 1981) where the only problem is to define M/P ratio (mean atomic weight: M-molecular weight divided by the P-number of atoms). In case of silicate rocks - M/P=21 and for sulphide massive ores - M/P=40. Thus, Debye temperature calculation allows Dergachov and Starostin (1981) to estimate the formation and transformation conditions of rocks and ores. In such a way, they distinguish facieses of volcanic rocks, regional metamorphism changes, the thermodynamic conditions of metamorphism, dynamothermal metamorphism, etc. When we investigate rocks of endogenous deposits, always there are some other mainly ore components in them (e.g. sulphides etc.). That leads to the change of the M/P ratio. On the other hand the presence of the ore components leads to the increase of rock density. So the density increment will cause the increment of M/P ratio. In this connection with interpolation between values, calculated by both formulae (for rocks and massive ores), on the basis of density variations, we can determine a real value of the Debye temperature by the formula: = r - (r - o)( - 2.7)/2
where: r - for rocks; o - for ores (see Dergachov and Starostin 1981).
Such a method of calculation allows to determine that important parameter with 1% precision, for density variation of 0.1 t/m3. This is quite enough for geological and other interpretations. For comparison a table with the results of Debye temperature calculation (for pure rocks and ores, and for interpolated values also) will be attached in to the full text. Such interpolation method for the Debye temperature calculation could be based on other parameter or component which correlate well with M/P ratio variations.
Dergachov AL., Starostin, VI. The Debye characteristic temperature as indicator for formation and transformation conditions of rocks and ores. 1981, Ore Deposit Geology, 6, 67-75
Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00
Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:
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