Renewed Search for FUN (Fractionated and Unidentified Nuclear Effects) in Primitive Chondrites

摘要: Ca-Al-rich inclusions (CAIs) found in primitive chondrites record processes and conditions of the earliest solar system as they are oldest known solid objects formed [1,2]. CAIs with fractionation unidentified nuclear anomalies (FUN CAIs; [3]) very rare thusfar exclusively CV carbonaceous (e.g., Allende Vigarano)[4]. FUN characterized by large nucleosynthetic several elements (Ca, Ti, Si, Sr, Ba, Nd, Sm), mass-dependant isotope (Mg, O), little initial {sup 26}Al [4,5 reference therein]. Formation thermal processing presolar dust aggregates prior to injection into protoplanetary disk has been proposed. More recently [5] proposed that from a protosolar molecular cloud after but before 27}Al were completely homogenized. Therefore discovering more perform U-Pb other short-lived chronometric dating will provide key constraints on age system, isotopic composition cloud, stages timing radionuclide nascent system. Most discovered studied > 30 yr ago, their ratios determined using ionization mass spectrometry (TIMS). these almost or entirely consumed during respective analyses. identified new CAI (NWA 779 KS-1) based O Mg SIMS MCICPMS, respectively. We have initiated systematic search for chondrites, taking advantage effects no inferred 26}Al. Our strategy is use newly developed sample cells capable holding slabs meteorites laser ablation interfaced multicollector inductively coupled plasma (LA-MC-ICPMS) at UC Davis. Here report findings our describe instrument setup we provides rapid throughput accurate results.