Sentences with word «pyroxene»

Dark, angular crystals of pyroxene floated alongside white, chunky feldspars.

The scientists infer that late in the magma - ocean crystallization, iron - rich pyroxene and ilmenite, which formed late and at the crust - mantle boundary, might have begun to sink, and early - formed magnesium - rich olivine might have begun to rise.

Humayun's team analyzed rock pieces rich in pyroxene and feldspar — minerals that would have been among the first to settle out of a cooling magma chamber.

Although the heat of the upper mantle might help the olivine or pyroxene crystals within the rocks grow larger again, or «heal,» the two rock types are competing for space: Each is actually inhibited in its growth by the other's presence.

The huge Keck II telescope joined the Vesta patrol in 1999, producing spectra that showed Vesta's surface is covered with pyroxene and olivine, minerals common in terrestrial volcanoes.

And NASA's James Webb Space Telescope, planned for launch in 2018, he says, could study the chemical composition of vaporized material sputtered off the planet by the intense radiation of its star, sniffing out signs of rocks like pyroxene and olivine to track geochemical cycles on the distant world.

The Vesta samples contain pyroxene, a mineral commonly found in lava flows both on Earth and on the moon.

In 2012, he and his colleagues published a paper in Nature Geoscience that found compositional evidence for an impact within Procellarum — a type of pyroxene mineral that is found in other, known impact basins such as South Pole — Aitken and is associated with the melting or excavation of mantle rock from an asteroid impact.

The north - south variation in minerals indicates that the deep crust exposed in the southern Rheasilvia region is dominated by pyroxene - rich, diogenitic material while the equatorial region seems to retain the most ancient eucrite - rich mineralogy.

Outside of that is a ring in which pyroxene mixes with the standard crustal rocks of the lunar highlands.

In this image, pyroxenes appear to be various colors due to the use of a polarizer lens.

The different minerals visible on this picture are called pyroxene.

The signatures of pyroxene, an iron - and magnesium - rich mineral, in these meteorites have been found to match those of rocks observed on Vesta's surface.

That central region is surrounded by a ring of material dominated by magnesium - rich pyroxene, a mineral thought to be plentiful in the lunar mantle.

(Blues are pyroxene; reds are olivine.)

Earth's upper mantle, which makes up much of the lithosphere, is a relatively simple mix, consisting primarily of two rock types, olivine and pyroxene.

Typically, the first to crystallize are two magnesium - and iron - rich minerals (olivine and pyroxene) that are both a little denser than the magma, and sink down through it, then a mineral (plagioclase feldspar), that is less dense and floats to the surface.

Laboratory experiments show that under the conditions prevailing at these vents, ultramafic silicates — rocks rich in iron or magnesium, such as olivine and pyroxene — can react to produce hydrogen in a process commonly referred to as serpentinization.

«Missing» centers (origin of syenite boulders at Lothidok, Kokiselei; mafic centers with biotite, pyroxene, kaersutite megacrysts recorded at Kalodirr)

Moriarty and Pieters found several such craters in the volcanic patch where the pyroxene material has been re-excavated.

With that in mind, Moriarty says a good spot to land might be near the border of the volcanic center and the pyroxene ring.

NASA's Curiosity rover gets its first taste of Mars and finds plagioclase feldspar, pyroxene, and olivine minerals.

To the naked eye, pyroxenes are black minerals and are very abundant in basalts, such as the volcanic rocks found in Hawaii.