breccia: Quick Facts

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Breccia sample returned from the Moon by Apollo 15 astronauts in 1971. This sample was found at Spur Crater at the foot of the Apennine range near the Mare Imbrium. It is composed of broken and shock-altered fragments that were fused together after an impact of a large object created the Imbrium Basin.

discrete particles of lunar soil

(Top) Basalt and (bottom) breccia samples returned from the Moon by Apollo 15 astronauts in 1971.The dark basalt rock, collected near Hadley Rille on the edge of the Imbrium Basin (Mare Imbrium), is about 13 cm (5.1 inches) long and is representative of the mare lavas that filled the basin 3.3 billion years ago, several hundred million years after the impact that created Imbrium. Its numerous vesicles were formed from bubbles of gas present in the lava when it solidified.The breccia sample, which measures about 6 cm (2.4 inches) across, was found at Spur Crater at the foot of the Apennine range, part of the material pushed up by the Imbrium impact. Dating from the formation of Imbrium, it is composed of broken and shock-altered fragments fused together during the impact.

Eight labeled rock samples are shown, including black glassy obsidian, speckled porphyry, striped calico sandstone, shell-filled coquina limestone, coarse breccia, layered banded gneiss, pale green fibrous talc schist, and greenish serpentine.

A chart categorizes common textural terms for rocks by grain size in millimeters, dividing them into igneous and metamorphic, sedimentary, and pyroclastic types, with terms like phaneritic, sand, silt, breccia, and ash shown in relation to size.

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volcanic breccia epiclastic breccia fault breccia orthobreccia intraformational breccia petromictic orthobreccia clastic rock rudite conglomerate tillite loess clay shale sandstone siltstone permeability lutite claystone

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sedimentary rock: Sedimentary rock types

Basalt sample returned by Apollo 15, from near a long sinous lunar valley called Hadley Rille. Measured at 3.3 years old.

(Bed) Rocks and (Flint) Stones