Primitive components in chondrites

Al- Mg, VIn-Cr, 1S2Hf- 2W, and 12iT- Xe. The Pb-Pb system provides the absolute time anchor for all systems (shown in Ma at the top of the diagram). For the 

Hf- W system, we will use CAIs and the initial ratio determined by Burkhardt et al. 

CAI E60 + Allende CAIs CAI E60 0 Allende Type CAI -0-Allende CAI AJEF 

Chronology of the solar system from radioactive isotopes 

CAIs also have the highest (26A1/27A1)0 ratios among solar system materials. The first inclusion shown conclusively to have formed with live 26A1, Allende WA, gave an 

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