![]() ![]() The chemical composition is dominated by the elements Fe, Ni and Co, which make up more than 95%. The troilite plates are called Reichenbach lamellae. Schreibersite and troilite also occur as plate shaped inclusions, which show up on cut surfaces as cm-long and mm-thick lamellae. Minor minerals, when occurring, often form rounded nodules of troilite or graphite, surrounded by schreibersite and cohenite. The overwhelming bulk of these meteorites consists of the FeNi-alloys kamacite and taenite. This implies that there were once at least this many large, differentiated, asteroids in the asteroid belt – many more than today. The IIE iron meteorites may be a notable exception, in that they probably originate from the crust of S-type asteroid 6 Hebe.Ĭhemical and isotope analysis indicates that at least about 50 distinct parent bodies were involved. Melting produced from the heat of impacts is another cause of melting and differentiation. The heat released from the radioactive decay of the short-lived nuclides 26Al and 60Fe is considered as a plausible cause for the melting and differentiation of their parent bodies in the early Solar System. Iron meteorites are thought to be the fragments of the cores of larger ancient asteroids that have been shattered by impacts. Iron meteorites have been linked to M-type asteroids because both have similar spectral characteristics in the visible and near-infrared. All the largest known meteorites are of this type, including the largest-the Hoba meteorite.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |