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| A NEW EXPLORATION TO THE RARE EARTH ELEMENT VARIATIONS IN DUCTILE SHEAR ZONE: Discussion on the volume loss formula and reasons for REE variation |
| LUO Wen-juan, ZHANG De-hui |
| School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China |
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Abstract In his article "The application of rare earth elements in the volume deficiency of ductile shear zone" published in Geological Review in 1999, Zhou explained the reason for REE variation with O' Hara's volume loss formula. However, a detailed analysis on the original derivation of O' Hara's formula shows that the application of the volume loss formula is conditional on cases. Actually, the volume loss is not the real reason for variation of REE in the shear zone, but just the phenomenon for the reason which causes the variation of REE. The mess transfer caused by fluid process is the essential factor for variation of REE. Based on previous researches, other direct and indirect factors for variation of REE in shear zones are summarized, including the "extraction" of melt to REE under strong stress, the residues of accessory minerals, the dynamic control of oxygen fugacity on variation of REE, the effective fluid filtration with high water/rock ratio, the dynamic changes of distribution coefficients, and the driving of stress on the elements.
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Received: 22 May 2009
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2009, Vol. 18 
