A nebular origin for chondritic fine-grained phyllosilicates.
Hydrated minerals occur in accretionary rims around chondrules in CM chondrites. Previous models suggested that these phyllosilicates did not form by gas-solid reactions in the canonical solar nebula. We propose that chondrule-forming shock waves in icy regions of the nebula produced conditions that allowed rapid mineral hydration. The time scales for phyllosilicate formation are similar to the time it takes for a shocked system to cool from the temperature of phyllosilicate stability to that of water ice condensation. This scenario allows for simultaneous formation of chondrules and their fine-grained accretionary rims.
Ciesla
Fred J
FJ
Department of Planetary Sciences, Lunar and Planetary Laboratory, University of Arizona, 1629 East University Boulevard, Tucson, AZ 85721, USA. fciesla@lpl.arizona.edu
Lauretta
Dante S
DS
Cohen
Barbara A
BA
Hood
Lon L
LL
D007053:Ice; D019110:Meteoroids; D011312:Pressure; D017640:Silicates; D013696:Temperature; D013816:Thermodynamics; D014867:Water
D007053:Ice; D017640:Silicates; D014867:Water