On the heavy elements content of sediments and rocks from two semiclosed ecosystems: Proglacial Lake Balea (Fagara Mountains) and Crater Lake St. Ana (Harghita Mountains)

Abstract

The content of seven heavy elements (natural Sc and Cr, Co, As, Sb, Br and Se as possible pollutants) was determined by the Neutron Activation Analysis (NAA) in 29 samples of sediments and surrounding rocks collected from proglacial Lake Bå alea (Få agå aras Mountains) and crater St. Ana Lake (Harghita Mountains) to estimate the degree of anthropogenic pollution, as well as the sediments provenance. Consequently, we have found that, within experimental uncertainties, the content of the considered elements in sediments was close to those of surrounding rocks, and, at the same time, comparable with the normal environmental content as deˇned by the Romanian Regulations, which enabled us to consider them as normal, nonpolluting constituents of lake sediments. A further R-mode, Principal Component Analysis (PCA), performed for each lake, showed that Sc, Cr, and Co, on the one hand, and As, Sb, Br and Sb, on the other, form two distinct clusters, regardless of the lake, while the Q-mode analysis pointed to a different lake geochemistry with respect to sediments as well as rocks.

Spatial distribution and geochemistry of major and trace elements from Mohoș peatland, Harghita Mountains, Romania

“…One of the anthropogenic sources of chromium is the metallurgical industry (Maas et al, 2010). The average content of chromium determined from sediments extracted from St. Anna volcanic lake near Mohoș peatland is 31 ± 3 mg/kg, with a standard deviation of 29 ± 10 (Duliu et al, 2013), and from andesites and dacites taken from the Ciomadul volcanic structure, Seghedi et al (1986) give a chromium content of 11–47 mg/kg. In a previous study by Pantelica et al (1997), the concentration of chromium in the Poiana Stampei peatland is revealed to be of 9.7 ± 0.5 mg/kg.…”