Cumulate eucrite
A cumulate eucrite is a coarse-grained Vesta rock formed when crystals settled out of magma.
A cumulate eucrite is made of the same minerals as a basaltic eucrite, pyroxene and plagioclase, but they are coarser-grained and formed by crystals accumulating in a body of magma rather than by a lava cooling as a whole. As a result, cumulate eucrites have different trace element patterns, typically with low overall rare earth elements and a strong positive europium anomaly from the abundant plagioclase.
The best-known examples include Moore County, which fell in North Carolina in 1913, and Serra de Magé, which fell in Brazil in 1923. Their pyroxenes often show broad exsolution lamellae, a sign of slow cooling at depth.
Cumulate eucrites help reconstruct Vesta's crust. They seem to represent intrusions deeper than the lavas but shallower than the diogenites. Some of them give younger ages than basaltic eucrites, which raises interesting questions about how long magmatism or reheating lasted on Vesta.
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