Discovery of Fundamental Mass Ratio Relationships of Whole-Rock Chondritic Major Elements: Implications on Ordinary Chondrite Formation and on Planet Mercury's Composition
Abstract
Description
The high occurrence on Earth of ordinary chondrite meteorites and the making of models based upon arbitrary assumptions has led to some confusion about the origin of ordinary chondrites. Major element fractionation among chondrites has been discussed for decades as ratios relative to Si or Mg. Expressing ratios relative to Fe leads to a new relationship admitting the possibility that ordinary chondrite meteorites are derived from two components: one is a relatively undifferentiated, primitive component, oxidized like the CI or C1 chondrites; the other is a somewhat differentiated, planetary component, with oxidation state like the reduced enstatite chondrites. Such a picture would seem to explain for the ordinary chondrites, their major element compositions, their intermediate states of oxidation, and their ubiquitous defiencies of refractory siderophile elements. I suggest that the planetary component of ordinary chondrite formation consists of planet Mercury's missing complement of elements, presumably separated from protoplanetary Mercury during its formation.