Search results for "Light isotope"
showing 2 items of 2 documents
Planktonic foraminifera biozones and isotope stratigraphy of the Cenomanian-Turonian boundary in the western part of the Kopet-Dagh Basin, NE Iran
2018
Abstract A biostratigraphic study based on the planktonic foraminifera and isotope stratigraphy of the Cenomanian-Turonian interval has been undertaken in the western part of the Kopet-Dagh Basin (NE Iran). In this research, two stratigraphic sections including: Maraveh Tappeh and Qareh Galdy have been sampled and studied. Based on planktonic foraminifera, three biozones were assigned to this interval. These are the Rotalipora cushmani Zone, Whiteinella archaeocretacea Zone and Helvetoglobotruncana helvetica Zone, These biostratigraphic data confirm a gradual faunal turnover of planktonic foraminifera, at the Cenomanian-Turonian boundary in Whiteinella archaeocretacea Zone characterized by:…
Multiple coulomb excitation of202Hg and204Hg
1985
Multiple Coulomb excitation measurements on202, 204Hg have been performed with 5 MeV/u208Pb projectiles. The ground bands are excited up to the newly discovered 6+ states and B(E2) values are derived for the 4+→2+ and 6+→4+ transitions. Whereas the 2+ and 4+ levels in the Hg isotopes with 196≦A≦204 have an almost constant energy, the 6+ levels increase in202Hg and204Hg, compared to the lighter isotopes, by approximately 100 and 300 keV, respectively. The relative B(E2) values in both nuclei show that the collectivity in the neutron rich Hg nuclei is of more complex origin than expected from the few proton and neutron holes with respect to the 82 and 126 major shells.