摘要：The aim of this research is to reconstruct palaeoredox conditions during sedimentation of the Jeleni¨®w Claystone Formation deposits, using framboid pyrite diameter measurements. Analysis of pyrite framboids diameter distribution is an effective method in the palaeoenvironmental interpretation which allow for a more detailed insight into the redox conditions, and thus the distinction between euxinic, dysoxic and anoxic conditions. Most of the samples is characterized by framboid indicators typical for anoxic/euxinic conditions in the water column, with average (mean) values ranging from 5.29 to 6.02 ¦Ìm and quite low standard deviation (SD) values ranging from 1.49 to 3.0. The remaining samples have shown slightly higher values of framboid diameter typical for upper dysoxic conditions, with average values (6.37 to 7.20 ¦Ìm) and low standard deviation (SD) values (1.88 to 2.88). From the depth of 75.5 m till the shallowest part of the Jeleni¨®w Claystone Formation, two samples have been examined and no framboids has been detected. Because secondary weathering sho uld be excluded, the lack of framboids possibly indicates oxic conditions in the water column. Oxic conditions continue within the W¨®lka Formation based on the lack of framboids in the ZB 51.6 sample.
