Progress of REE isotopic studies on cosmochemistry

2016 Fiscal Year Final Research Report

• Project/Area Number: 26247095
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Geochemistry/Cosmochemistry
• Research Institution: Nagoya University (2015-2016); Hiroshima University (2014)
• Principal Investigator: HIDAKA HIROSHI 名古屋大学, 環境学研究科, 教授 (10208770)
• Co-Investigator(Kenkyū-buntansha): 米田 成一 独立行政法人国立科学博物館, 理工学研究部, グループ長 (60210788)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 希土類元素 / 同位体 / 隕石 / 月 / 質量分析

Outline of Final Research Achievements

The chemical technique for mutual separation of rare earth elements (REEs) was developed, and was applied for isotopic studies of cosmocheimcal materials. Among a series of eucrites that are considered to have been differentiated in the early solar system, dessert eucrites showed significant effect of terrestrial contamination, and their Rb-Sr system were largely disturbed. On the other hand, the Sm-Nd system of a series of eucrites showed less effect of the terrestrial contamination, and provided chronological information on the early differentiation in the solar system. All five kinds of luna surficial materials collected by the Apollo mission showed isotopic excesses of lighter isotopes having proton-rich nuclides and heavier isotopes having neutron-rich nuclides of some REE caused by neutron capture and spallation reactions due to long-term exposure by cosmic rays.

Free Research Field

宇宙化学