Niobium-Zirconium Chronometry and Early Solar System Development
Abstract
Niobium-92 ( 92 Nb) decays to zirconium-92 ( 92 Zr) with a half-life of 36 million years and can be used to place constraints on the site of p -process nucleosynthesis and the timing of early solar system processes. Recent results have suggested that the initial 92 Nb/ 93 Nb of the solar system was high (>10 −3 ). We report Nb-Zr internal isochrons for the ordinary chondrite Estacado (H6) and a clast of the mesosiderite Vaca Muerta, both of which define an initial 92 Nb/ 93 Nb ratio of ∼10 −5 . Therefore, the solar system appears to have started with a ratio of <3 × 10 −5 , which implies that Earth's initial differentiation need not have been as protracted as recently suggested.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 01, 2002
- Source ID
- 10.1126/science.1067400
Entities
People
- Alex N. Halliday
- Bodo Hattendorf
- Brigitte Zanda
- Der-chuen Lee
- Detlef Günther
- Maria Schönbächler
- Mark Rehkämper
- Michèle Bourot-denise
Organizations
- ETH Zurich
- Muséum national d'histoire naturelle
- Rutgers University