Neutron activation analysis in geochemical characterization of Jurassic-Cretaceous sedimentary rocks from the Nordvik Peninsula
Abstract
As a part of geophysical, stratigraphical and paleontological study aimed at precise correlation of the Jurassic-Cretaceous (J/K) boundary interval in the Tethyan and Boreal Realms, detailed magnetostratigraphic and biostratigraphic profiles with well-calibrated J/K boundary have been selected from several localities for geochemical characterization. Instrumental and radiochemical neutron activation analyses (INAA and RNAA, respectively) were employed in the characterization of a vertical profile around the supposed J/K boundary in the Boreal Realm situated on the Nordvik Peninsula, Northern coast of Middle Siberia (Laptev Sea), Russia, for which an iridium anomaly has been reported in literature.
INAA enabled determination of about forty major and trace elements. An RNAA procedure for assaying platinum group elements (PGE) has been tested consisting in sample decomposition by alkaline-oxidative fusion, reduction of PGE, and precipitation of their sulphides. decomposition of burried organic matter.