Fragmental breccia
A fragmental breccia consists of rock and mineral fragments in a matrix of finer crushed debris, with no melt binding them.
A fragmental breccia is made of angular pieces of rock and mineral held together by finer fragments of the same material, without any significant impact melt. It records crushing and mixing by impacts at relatively low energy.
On the Moon and asteroids, fragmental breccias form in the debris thrown out of craters and in the churned surface layer. Many eucrites, howardites and lunar meteorites are fragmental breccias. They were compacted by later impacts or by the weight of material above them.
Geologists distinguish them from regolith breccias, which also contain features from direct exposure at the very surface, such as implanted solar wind gases and tiny glass beads, and from impact melt breccias, in which fragments are enclosed by once-molten rock. Identifying which kind of breccia a meteorite is helps reconstruct the processes on its parent body's surface.
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