Compositional analyses of small lunar pyroclastic deposits using Clementine multispectral data
Compositional analyses of small lunar pyroclastic deposits using Clementine multispectral data
复制标题
使用 Clementine 多光谱数据对小型月球火山碎屑沉积物进行成分分析
DOI：
10.1029/1999je001070
复制
发表时间：
2000
影响因子：
--
通讯作者：
C. Coombs
中科院分区：
文献类型：
--
作者：
L. Gaddis;B. Hawke;Mark S. Robinson;C. Coombs
克莱门汀紫外可见光（UVVIS）数据被用来检查18个火山碎屑沉积物（15个小，3个大）在月球上的13个地点的组成。火山碎屑沉积物之间的成分变化主要是由于不同数量的新的玄武岩（或少年）的材料和改造当地的物质夹带在喷发喷出物。火山碎屑存款成分的特征使我们能够了解月球爆发火山作用的机制。在阿特拉斯陨石坑观察到了单一地点的小火山碎屑沉积物之间成分差异的证据。在所有地点，小火山碎屑沉积物之间的成分变化与早期基于地球光谱的分类一致：可以观察到三个成分组，并注意到从第1组到第2组再到第3组的镁铁质吸收带强度增加的趋势。这里重新定义的第1组矿床包括Alphonsus West、Alphonsus Southeast、Alphonsus Northeast 2、Atlas South、Cruger、富兰克林、Grimaldi、Lavoisier、Oppenheimer、Orientale和Riccioli。第1组矿床类似于月球高地，具有较弱的镁铁质带和相对较高的UV/维斯比值。第2组矿床包括Alphonsus Northeast 1、Atlas North、Eastern Frigoris East和West以及Aristarchus Plateau;第2组矿床类似于成熟月海，具有中等镁铁质带深度和中等UV/维斯比。单一的第3组存款，J. Herschel，有一个相对较强的镁铁质带和低的UV/维斯比，橄榄石是一个可能的年轻的组成部分。这些群中的两个矿床Orientale和Aristarchus是大型火山碎屑矿床。第三个大型火山碎屑存款，阿波罗17号/金牛座Littrow，有一个非常弱的镁铁质带和高UV/维斯比，它不属于任何组成组的小型火山碎屑矿床。所观察到的成分变化表明，高地和海的材料也存在于许多大型和小型火山碎屑沉积物，他们建议，火山玻璃或球体可能不是占主导地位的少年成分在所有大型火山碎屑沉积物。
Clementine ultraviolet-visible (UVVIS) data are used to examine the compositions of 18 pyroclastic deposits (15 small, three large) at 13 sites on the Moon. Compositional variations among pyroclastic deposits largely result from differing amounts of new basaltic (or juvenile) material and reworked local material entrained in their ejecta upon eruption. Characterization of pyroclastic deposit compositions allows us to understand the mechanisms of lunar explosive volcanism. Evidence for compositional differences between small pyroclastic deposits at a single site is observed at Atlas crater. At all sites, compositional variation among the small pyroclastic deposits is consistent with earlier classification based on Earth-based spectra: three compositional groups can be observed, and the trend of increasing mafic absorption band strength from Group 1 to Group 2 to Group 3 is noted. As redefined here, Group 1 deposits include those of Alphonsus West, Alphonsus Southeast, Alphonsus Northeast 2, Atlas South, Cruger, Franklin, Grimaldi, Lavoisier, Oppenheimer, Orientale, and Riccioli. Group 1 deposits resemble lunar highlands, with weak mafic bands and relatively high UV/VIS ratios. Group 2 deposits include those of Alphonsus Northeast 1, Atlas North, Eastern Frigoris East and West, and Aristarchus Plateau; Group 2 deposits are similar to mature lunar maria, with moderate mafic band depths and intermediate UV/VIS ratios. The single Group 3 deposit, J. Herschel, has a relatively strong mafic band and a low UV/VIS ratio, and olivine is a likely juvenile component. Two of the deposits in these groups, Orientale and Aristarchus, are large pyroclastic deposits. The third large pyroclastic deposit, Apollo 17/Taurus Littrow, has a very weak mafic band and a high UV/VIS ratio and it does not belong to any of the compositional groups for small pyroclastic deposits. The observed compositional variations indicate that highland and mare materials are also present in many large and small pyroclastic deposits, and they suggest that volcanic glasses or spheres may not be dominant juvenile components in all large pyroclastic deposits.