Search for live 182Hf in deep-sea sediments

The presence of live (182)Hf (t(1/2) similar to 9 Myr) in the early solar system is well established but the understanding of its abundance is still challenging. Live (182)Hf is expected to be present in the interstellar medium (ISM) as a result of recent nucleosynthesis activity. We are attempting a search for live (182)Hf possibly deposited on Earth. The search focuses on deep-ocean sediments and a method for chemical extraction of the Zr-Hf fraction from sediments has been developed. The detection of (182)Hf is performed at the Vienna Environmental Research Accelerator (VERA). Measurements of Hf and W isotopic abundances for the Zr-Hf fraction extracted from deep-sea sediment samples were performed. Present limits for the (182)Hf abundance derived from the measured isotopic abundances are discussed. (C) 2003 Elsevier B.V. All rights reserved.