engleski

Distribution of rare earth elements in sediments from the Tuzla salt mine, Bosnia and Hercegovina

The concentration of rare earth elements (REE's) in the mineral tuzlaite (a new mineral, discovered in the evaporite series of the Tuzla salt mine in Bosnia and Hercegovina) and in surrounding marls were determined by instrumental neutron activation analysis (INAA). The crystal structure and crystallochemical characteristics of tuzlaite strongly influence the concentrations and distribution of individual rare earth elements. As a consequence of this, the REE content of the marls is greater than in tuzlaite by a factor of hundred. The mineral tuzlaite displays a significant negative Eu and Yb anomaly and a positive Tb anomaly, contrary to the marls which show no pronounced anomalies. The distribution of REE's in the proximal marls shows the same overall pattern as in the distant northupite - containing marl equivalents. The marl that contains tuzlaite also shows higher overall concentrations of rare earth elements than the distant marls, indicating a sequential diagenetic loss, probably due to recrystallization. The causes and implications of specific REE distributions are discussed in terms of HREE vs. LREE ratios.

REE in sediments; anomalies; tuzlaite; northupite; marl; Tuzla; BiH

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