Assessment of sessile oak (quercus petraea L.) leaf as bioindicator for exploration geochemistry

The element contents of sessile oak (Quercus petraea L.) leaves which grow on hydrothermally altered area with high element contents were studied at Gümüshane and its near vicinity. The aim of this study is to determine threshold element contents of Q. petraea L. leaves growing on the area. For this purpose, oak leave samples collected were analyzed by inductively coupled plasma-mass spectrometry for concentrations of some elements which were the group of most common trace elements in exploration geochemistry studies. The assessment of the element contents of the oak leaf is based on the descriptive statistics and computations of threshold values of leaves depending on statistical parameters and average element contents of the plants growing on lands in normal background values for the elements. According to Q-Q (normal quantile-quantile) plots, the Kolmogorov-Smirnov tests etc., all the elements, do not pass normality tests. Because of that, threshold values of the elements in leaves of oak were computed by median+median absolute deviation (MAD) and median+2MAD used in raw values for the elements. The data revealed that concentration levels of the examined elements in the leaves in the study area were determined as above and/or exceeded the upper limit of the normal range than in leaf of oak (Q. petraea L.) which grows on lands with normal elements background. Therefore, it is concluded that leaves of Q. petraea L. can be used as bioindicator in exploration geochemistry, especially for base metal ore deposits.