Sentences with phrase «in pyroxene»
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.
http://science.sciencemag.org/ Not exact matches
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.
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.
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.
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.
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.
To the naked eye, pyroxenes are black minerals and are very abundant in basalts, such as the volcanic rocks found in Hawaii.
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.