Nature of phyllosilicates in Klio family members lacking the 0.7 μm band

Determine whether the 77% of asteroids in the Klio collisional family that do not show the 0.7 μm hydration band have fewer phyllosilicates overall or have phyllosilicate assemblages that are more Mg-rich, or both, in order to constrain the degree of aqueous alteration of the Klio family parent body.

Background

Visible spectroscopy of the Klio family indicates spectral heterogeneity: approximately 23% of members display the 0.7 μm band associated with Fe-bearing phyllosilicates, while 77% do not. The absence of the 0.7 μm feature could arise from either a lower abundance of phyllosilicates or a dominance of more Mg-rich phyllosilicates, both of which would bear on the extent of aqueous alteration experienced by the parent body.

Resolving which scenario (or both) applies is important for interpreting the family’s alteration history and the mineralogical diversity within the inner main belt’s primitive populations.