The Mass Spectrometry society of Japan - The 71st Annual Conference on Mass Spectrometry, Japan
Japanese

Abstract

Table of contents

Timetable

Plenary Lecture

Symposium Sessions (Day1, Day2, Day3)

Basic Sessions (Day1, Day2, Day3)

Young Researchers' Sessions (Day1, Day2, Day3)

Poster Presentations (Day1, Day2, Day3)

Special Evening Sessions

Corporate Program

Basic Sessions

Day 1, May 15（Mon.）　10:36-10:54　Room B (Room 1202)

1B-O-1036　　PDF

Improvement of High Precision Al-Mg Isotope Analysis by SIMS and Application to Meteoritic Chondrules

(1Osaka Univ., 2University of Bologna, 3UW-Madison)
oKohei Fukuda1, Guillaume Siron2, Noriko Kita3

Secondary Ion Mass spectrometry (SIMS) is a powerful tool for revealing the timescale of geological and cosmochemical events recorded in small (~µm to tens of µm) solids. In the earliest stage of our Solar System evolution, the presence of short-lived radionuclides such as Aluminum-26 (26Al), which decays to 26Mg with a half-life of 0.7 million years (Ma), has been inferred from SIMS analyses of the Solar System oldest solids (Ca-Al-rich inclusions: CAIs). Here we improved the precision and accuracy of SIMS Al-Mg analysis for plagioclase (Na, Ca)(Si, Al)4O8 and Al-rich glass, in order to better understand the formation timescale of asteroidal seeds, called chondrules. To improve the precision and accuracy of SIMS Al-Mg analyses, we developed analytical methods using the multi-collector SIMS CAMECA IMS 1280 equipped with the radio-frequency plasma ion source at the University of Wisconsin-Madison. The uncertainties (2σ) on the determined chondrule formation ages are typically ±0.1–0.2 Ma, which are ~2–3 times better than those in previous studies. Based on the newly determined high-precision chondrule formation ages, we will discuss the timescale of chondrule formation and the implications for the evolution of the Solar protoplanetary disk.