Angra dos Reis meteoriteachondrite/ A9650M Meteorites, micrometeoritesThe preatmospheric mass of Angra dos Reis is estimated to be about 80 kg, based on cosmic ray track densities of 13 脳 10 6 cm 2 in feldspars, olivines, and pyroxenes. The 244Pu-fission track densities in pyroxenes ...
In particular we studied the meteorite Angra dos Reis (ADR), an augite achondrite, which is known to have a high uranium concentration (> 170 p.p.b. by weight) 7–9 and for which the concentrations 10–12 of rare gases, both fissiogenic and cosmogenic, are well known. ADR is rich...
THIS unique olivine-clinopyroxenite meteorite (angrite) has been intensively studied first because it contains evidence of the existence of extinct radionuclidesand second because it is the meteorite richest in Ti and Ca and is therefore most similar to lunar rocks. In addition, it has been ...
SmNdPu timepieces in the Angra dos Reis meteorite We have studied SmNd systematics in pyroxene and phosphate mineral separates of Angra dos Reis. A pyroxene-phosphate internal isochron age ofT2 = 4.55 卤 0... W G.,Lugmair,and,... - 《Earth & Planetary Science Letters》 被引量: 0发表...
The rare-earth and barium concentrations of Angra dos Reis (stone) and its composition (more than 90% augite), argue against this meteorite being a cumulate from a normal achondritic liquid; the Angra dos Reis (stone) rare-earth... JA Philpotts,CC Schnetzler - Springer Netherlands 被引量...
Marti, Sm-Nd-Pu timepieces in the Angra Dos Reis meteorite, Earth Planet. Sci. Lett. 35 (1977) 273-284.Lugmair, G. W., and K. Marti (1977), Sm-Nd-Pu timepieces in the Angra dos Reis meteorite, Earth Planet. Sci. Lett., 35, 273-284....
Xenon released in stepwise heating of the Angra dos Reis stone is found to be largely cosmogenic (from cosmic ray spallation reactions) and fissiogenic (presumably from the spontaneous fission of 82 million year Pu 244). This meteorite contains the largest proportion of these two components ...
The crystal structure of fassaite from the Angra dos Reis meteorite has been determined by least-squares refinement of three-dimensional X-ray data to an R value of 3.3%. The pyroxene is monoclinic, space group C2/c, with unit-cell dimensions a = 9.738(1), b = 8.874(2), c = 5.2827...
Mao, H.K., Bell, P.M., Virgo, D.: Crystal-field spectra of fassaite from the Angra dos Reis meteorite. Earth Planet. Sci. Lett. 35 , 352–356 (1977)Bell PM, Mao HK (1977) Crystal-Field Spectra of Fassaite from the Angra Dos Reis Meteorite. Abstracts Lunar Planet Sci Conf 8:...
We have resolved literature Xe data for the Angra dos Reis meteorite into constituent spallation, fission and trapped components. The spallation Xe compositions vary over a range wider than observed in any other samples, including lunear samples. These variations are due to the mixing of spallation...