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7

First, note that this plot is normalized to a reference, here the composition of CI chondrites (your version lacks the Y axis label, it's figure 2.1 from Walker 2016). So if the concentration of highly siderophile elements (HSE) seems uniform, it's partly because it is a relative concentration, not an absolute one. If you look at the raw data (Table 1.1), ...


5

Above the asthenosphere is the lithosphere. The main constituent of the lower lithosphere is peridotite, a coarse-grained igneous rock containing the minerals olivine and pyroxene. Samples of peridotite can be found in the surface. Sections of ocean crust can be uplifted onto continental margins, forming ophiolites (perhaps the best-known example being the ...


5

From the comments: And indeed, after browsing trough a few sections they seem to assume that "Liquid metal separates rapidly from liquid silicate", like oil and water, and they don't mix later. Very interesting. I wonder what's @Gimelist opinion about this. You are very correct. The answer is simple: the core and mantle are immiscible. The core ...


4

To complete the first answer with bigger scale images, here are some pictures of well-known mantle outcrops in Italy and Corsica (figure 4 from Rampone et al. 2020): The caption reads: (a) Centimeter-thick pyroxenite layers embedded in the External Ligurides mantle peridotites (Northern Apennines). (b) Partially dissolved pyroxenite layers (substituted ...


1

There are three ways samples of the mantle could arrive on the surface of the Moon. Drilling deep holes into the mantle, take a sample and send to the surface. As ejecta from a large deep impact crater, particularly where the crust is thin. During volcanic eruptions, the upward moving magma tears of chunks of mantle from the walls of the volcanic "vent&...


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