Very High Presolar Grain Abundances in the Cr Chondrite Que 99177
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Auger Nanoprobe analysis of presolar ferromagnesian silicate grains from primitive CR chondrites QUE 99177 and MET 00426
We have investigated the presolar grain inventories of two CR chondrites, QUE 99177 and MET 00426, which are less altered than most members of this meteorite group. Both meteorites contain high abundances of O-anomalous presolar grains, with concentrations of 220 ± 40 and 160 ± 30 ppm for QUE 99177 and MET 00426, respectively. The presolar grain inventories are dominated by ferromagnesian silic...
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