Basaltic volcanism on the angrite parent body: Comparison with 4 Vesta
Basaltic volcanism on the angrite parent body: Comparison with 4 Vesta
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DOI：
10.1111/maps.13016
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发表时间：
2018-03-01
影响因子：
2.2
通讯作者：
Grady, M. M.
中科院分区：
文献类型：
--
作者：
Abernethy, F. A. J.;Verchovsky, A. B.;Grady, M. M.
来自8个安钠岩、7个榴辉岩和2个闪长岩的阶梯燃烧分析的碳和氮数据，以及另外9个榴辉岩和2个闪长岩的文献数据，被用来评估安安岩母体(APB)上的碳和氮结合和同位素分馏过程，以便与HED母体(4 Vesta)上的挥发行为进行比较。天使岩数据的一个子集之前已经报告过(Abernethy等人)。)。观察到两个不同的挥发性成分家族。它们是(1)中等挥发性物质(MVM)，主要在500-750℃之间燃烧，与陆地污染难以区分；(2)耐火材料(Rm)，主要在750℃以上释放，被认为是溶解在硅酸盐晶格中的碳(作为CO32-)和氮(作为N-2或NH4+)，符合轻微氧化(IW至IW+2)的硅酸盐FO(2)条件。深成岩和玄武岩(淬火)安山岩中碳和氮的同位素分馏趋势表明，这两种挥发性元素的行为是松散耦合的，但两种安山岩亚群的分馏过程不同。与榴辉岩和闪长岩的结果对比表明，4个灶台上碳、氮的形态与APB相似，后者的挥发分比前者更丰富。
Carbon and nitrogen data from stepped combustion analysis of eight angrites, seven eucrites, and two diogenites, alongside literature data from a further nine eucrites and two diogenites, have been used to assess carbon and nitrogen incorporation and isotope fractionation processes on the angrite parent body (APB), for comparison with volatile behavior on the HED parent body (4 Vesta). A subset of the angrite data has been reported previously (Abernethy etal. ). Two separate families of volatile components were observed. They were (1) moderately volatile material (MVM), mostly combusting between 500 and 750 degrees C and indistinguishable from terrestrial contamination and (2) refractory material (RM), mainly released above 750 degrees C and thought to be carbon (as CO32-) and nitrogen (as N-2 or NH4+) dissolved within the silicate lattice, fitting with the slightly oxidized (IW to IW+2) angrite fO(2) conditions. Isotopic fractionation trends for carbon and nitrogen within the plutonic and basaltic (quenched) angrites suggest that the behavior of the two volatile elements is loosely coupled, but that the fractionation process differs between the two angrite subgroups. Comparison with results from eucrites and diogenites implies similarities between speciation of carbon and nitrogen on 4 Vesta and the APB, with the latter being more enriched in volatiles than the former.