Differentiation of the Generation Potential of the Menilite and Istebna Beds of the Silesian Unit in the Carpathians Based on Compiled Pyrolytic Studies

The study of the source rocks was carried out with the use of various analytical methods in order to assess their generation potential and to predict the decomposition products of organic matter. The selected samples from the Menilite Beds from the Silesian and Dukla units, as well as the Istebna layers from the Silesian unit, which are classified as weak and medium source rocks in the Carpathian oil system, were examined. The generation potential and type of the products obtained from the pyrolysis of the analyzed source rocks, despite the often comparable overall content of organic matter, are significantly different. Menilite shale generated a higher abundance of hydrocarbons (alkanes, alkenes, and isoalkanes) by stage pyrolysis, which suggested that the organic matter of Menilite shale is different from the Istebna source rocks. Moreover, the thermogravimetric analysis showed a two-stage weight loss in the case of Menilite shales, while the Istebna shales were characterized by a one-stage weight loss at higher temperature. For the Istebna layers, n-alkanes from the C1–C5 range were detected as the main pyrolysis products, which proves the gas-forming type of the organic matter dispersed in these sediments. Rock-Eval analyses showed that the organic matter reached a degree of maturity corresponding to the early thermocatalytic processes (the initial oil window stage) and therefore was able to generate liquid and gaseous hydrocarbons. The comparison of the decomposition temperatures of the organic matter from the Rock-Eval and TG analyses allowed us to conclude that both measurements correlate well and can be equally used to assess the level of thermal transformations of organic matter.

THE FITOACCUMULATION OF MOLYBDENUM AND MANGANESE IN ALSIKE CLOVER (TRIFOLIUM HYBRIDUM L.) AND GREATER PLANTAIN (PLANTAGO MAJOR L.)

Studies of molybdenum and manganese content in topsoil and plants were carried out in the Beskidy Wschodnie (Carpathians) in area of occurrence of menilite shales and the Otryt sandstones. The aim of the study was to evaluate the content of ­molybdenum and manganese in plants and the determination of a bioaccumulation of these two chemical elements in two species of plants (­Trifolium hybridum L. and Plantago major L.). Mo symbols were performed by means of ICP-MS method, and Mn were analyzed by means of ICP-OES method. Result of studies in the Trifolium hybridum L. have shown higher content of Mo in the area of occurence of menilite shales (in leaves – 14 mg/kg) than in the Otryt sandstones (in leaves – 0.30 mg/kg). Most Mn accumulates in leaves (86–257 mg/kg). The bioaccumulate indicator of Mo in individual plant species is different and ranges from 0.13 to 1.13. The highest rate of ­bioaccumulation of molybdenum (1.13) can be observed in Trifolium hybridum L., which inhabits areas of menilite shales.

The concentration of molybdenum and copper in rocks, soils and plants in the area of Jabłonki (Eastern Beskids Mts.) / Zawartość molibdenu i miedzi w skałach, glebach i roślinach w okolicy Jabłonek (Beskidy Wschodnie)

Molybdenum is one of the major trace elements for plants, but its excess and the deficiency of copper in soils can lead to the production of feed that may be toxic to animals and cause molybdenosis. Menilite shales that occur in the Eastern Beskids Mts. are characterised by an elevated content of this element. The concentration of molybdenum and copper has been determined in samples of bedrock, soils and plants (Trifolium hybridum L. and Plantago major L. plants), taken in the area of occurrence of menilite shales and the Otryt Sandstones. The molybdenum concentration in rocks varies from 0.80 to 40 mg/kg, in soils - from 1.97 to 19.58 mg/kg, and in plant material - from 0.54 to 11.76 mg/kg. The copper concentration in rocks ranges from 11 to 111 mg/kg, in soils - from 23 to 76 mg/kg, and in plants - up to 20 mg/kg. The average Mo concentration in all kinds of plants is significantly higher in the area of occurrence of menilite shales than in the area where the Otryt Sandstones are dominant. The higher content of Mo in the samples collected from clover was accompanied by the lower Cu/Mo ratio, which may cause a molybdenosis disease in animals in the study area.