Fractional melting aggregated melt

If the various melt fractions are collected together in the proportions they are extracted from the source (aggregated melt), the average liquid concentration is obtained by making the initial concentration equal to the sum of liquid and solid with the appropriate weight-fractions... 

Chondrules. Chondrules are major constituents of chondrites, which are millimeter- to submillimeter-sized spherules consisting of silicate phenocrysts (relatively large crystals), glassy mesostasis, and a small fraction of opaque phases (Lauretta et al. 2006 and references therein Chapter 8). Their textural, mineralog-ical, and chemical features suggest that chondrules formed from dust aggregates that were melted by localized transient high-temperature events and were cooled relatively rapidly. 

Chondrites contain a small fraction of chondrules that may have formed on asteroids. One rare type of chondrule (—0.1%) in type 4-6 ordinary chondrite breccias is composed largely of plagioclase (or mesostasis of plagioclase composition) and chromite (Krot et al, 1993). Krot and Rubin (1993) suggest that these chondrules may have formed by impact melting as they find impact melts with similar compositions inside shocked ordinary chondrites and such chondrules are absent in type 3 chondrites. In addition, some chromite-rich chondrules contain chromite-rich aggregates, which appear to be fragments of equilibrated chondrites. Other possible impact products were described in LL chondrites, which are mostly... 

Ionov et al. (1993a, 1996) found carbonate in spinel Iherzolite xenoliths as interstitial crystals and as aggregates with calcium-rich olivine and aluminum- and titanium-rich clinopyroxene. They interpreted the former to be primary and the latter as evidence for metasomatism by a carbonate-rich melt. Subsequently, Ionov (1998) measured trace-element abundances in the carbonates and coexisting phases, and proposed the aggregate carbonates were formed by crystal fractionation from a carbonate melt. That these carbonates represent crystallized cumulates,... 

Types of meteorite Meteorites may be subdivided into two main categories - unmelted meteorites, that is those which come from a parent body which has not been fractionated since its aggregation early in the history of the solar system, and melted, or differentiated meteorites (Fig. 2.8). Unmelted meteorites are stony meteorites, the chondrites, and are made up of the same silicate minerals that are found on Earth. Melted meteorites are of three types. They include some stony meteorites (the achondrites), the iron meteorites, whose composition is dominated by a metallic iron-nickel alloy, and stony-iron meteorites, meteorites which are made up of approximately equal proportions of... 

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