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The weathering-modified iridium record of a new Cretaceous–Palaeogene site at Lechowka near Chelm, SE Poland, and its palaeobiologic implications

100%

Racki G., Michalski M., Koeberl C., Harasimiuk M.

Acta Palaeontologica Polonica

2011

tom 56

nr 1

In the light of integrated biostratigraphic and geochemical data, a complete shallow−marine succession across the Cretaceous–Palaeogene (K–Pg) boundary, with the critical boundary clay coupled with a burrowed siliceous chalk (“opoka” in Polish geological literature), possibly equivalent of the basal Danian Cerithium Limestone in Denmark, has been discovered at Lechówka near Chełm, SE Poland. An extraterrestrial signature marking the K–Pg boundary is confirmed by anomalously high amounts of iridium (up to 9.8 ppb) and other siderophile elements (especially Au and Ni), as well as by an elevated Ir/Au ratio consistent with a chondrite meteoritic composition. The major positive iridium spike surprisingly occurs in Maastrichtian marls, 10 cm below the boundary clay interval, which can be explained by diagenetic mobilisation and re−concentration of the impact−derived components. Thus, intensively infiltrating, humic acid−rich ground waters during the long−lasting Palaeogene weathering in tropical humid regimes were probably responsible not only for the large−scale decalcification of the Lechówka section, but also for both downward displaced position of the iridium enrichment, a dispersed profile of this anomaly and its significantly lessened value, but still approaching an increase by a factor of 100. This modified record of the K–Pg boundary event points to a careful reconsideration of the iridium anomaly as a trustworthy marker for studying the extinction patterns across the K–Pg boundary, as supported by the recent data from New Jersey, USA.

Uptake of cadmium, lead, nickel and zinc from soil and water solutions by the nickel hyperaccumulator Berkheya coddii

64%

Mesjasz-Przybylowicz J., Nakonieczny M., Migula P., Augustyniak M., Tarnawska M., Reimold W. U., Koeberl C., Przybylowicz W., Glowacka E.

Acta Biologica Cracoviensia. Series Botanica

2004

tom 46

75-85

Berkheya coddii Roessler (Asteraceae), an endemic herbaceous and perennial nickel-hyperaccumulating plant growing on Ni-enriched ultramafic soils in South Africa, is perceived as a promising species for phytoremediation and phytomining due to its large biomass production and high Ni content. Total concentrations of a number of elements in mature leaves, soil and related bedrock were obtained. The average Ni concentration in leaves was 18,000 µg · g-1 dry mass, whereas in soil and bedrock the total amount of Ni was 1,300 µg · g-1 and 1,500 µg · g-1, respectively. Exceptionally high average Ni concentrations (55,000 ± 15,000 µg · g-1, n = 6) were found in B. coddii leaves from Songimvelo Game Reserve, including the highest-ever reported concentration of Ni in leaves (76,100 µg · g-1 - maximum value in a single sample). Young plants grown in pots with ultramafic soil accumulated small quantities of Cd, Pb or Zn, but the concentrations of these elements increased after the addition of metal solutions to the soil. Excised shoots immersed in concentrated solutions of Cd, Ni, Pb or Zn accumulated large amounts of these metals in the leaves.

Ograniczanie wyników

1 Acta Biologica Cracoviensia. Series Botanica

1 Acta Palaeontologica Polonica

2 Koeberl C.

1 Augustyniak M.

1 Glowacka E.

1 Harasimiuk M.

1 Mesjasz-Przybylowicz J.

1 Michalski M.

1 Migula P.

1 Nakonieczny M.

1 Przybylowicz W.

1 Racki G.

1 Reimold W. U.

1 Tarnawska M.

1 2011

1 2004

Wyniki wyszukiwania

The weathering-modified iridium record of a new Cretaceous–Palaeogene site at Lechowka near Chelm, SE Poland, and its palaeobiologic implications

Uptake of cadmium, lead, nickel and zinc from soil and water solutions by the nickel hyperaccumulator Berkheya coddii