Trace-element abundances and the origin of aluminum-26-bearing chondrules in unequilibrated ordinary chondrites

Calcium-aluminum-rich inclusions (CAis) typically contain radiogenic ^(26)Mg (^(26)Mg^*) from the decay of ^(26)Al, with (^(26)Al/^(27)Al); up to 5 x 10^(-5) [e.g., 1]. Some Al-rich chondrules from unequilibrated ordinary chondrites contain detectable ^(26)Mg^*, but (^(26)Al/^(27)Al); is lower [e.g., 2]