Petrography and geochemistry of five new Apollo 16 mare basalts and evidence for post‐basin deposition of basaltic material at the site
Petrography and geochemistry of five new Apollo 16 mare basalts and evidence for post‐basin deposition of basaltic material at the site
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五块新的阿波罗 16 号海玄武岩的岩相学和地球化学以及该地点玄武岩物质盆地后沉积的证据
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
J. J. Gillis
中科院分区：
文献类型：
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作者：
R. Zeigler;R. Korotev;L. Haskin;B. L. Jollif;J. J. Gillis
摘要-我们提出了从阿波罗16号风化层的5个2-4毫米玄武岩碎片的岩相学和地球化学。这些碎片是1）高钛玻璃斑状玄武岩，其成分与阿波罗17号高钛月海玄武岩相似，2）非常高钛玻璃斑状玄武岩，其成分与阿波罗12号和14号红黑色火山碎屑玻璃相似，3）粗晶高铝玄武岩，其成分与阿波罗14号5组高铝月海玄武岩相似，4）一种非常低Ti（VLT）的结晶玄武岩，其成分类似于月球24号VLT玄武岩，以及5）一种VLT玄武岩玻璃碎片，其成分类似于阿波罗17号VLT玄武岩。阿波罗16号基地以前曾报告过高钛玄武岩;其他玄武岩类型以前没有报告过。由于在阿波罗16号基地附近的高地上没有已知的隐藻或火山碎屑沉积物（排除了当地的起源），在阿波罗16号的古代风化角砾岩或阿波罗16号的土壤中收集到的玄武岩材料的证据很少，（排除盆地喷出物来源），我们推断阿波罗16号风化层中的玄武岩物质起源于阿波罗16号场地附近的玛丽亚，并通过小型到中型的盆地后撞击横向运输到场地。根据Clementine UVVIS数据得出的TiO 2浓度，位于阿波罗16号发射场以北约300公里处，是最有可能的高钛玄武岩物质来源。（撞击坑罗斯，阿拉戈，狄奥尼修斯，马斯基林，毛奇，Sosigenes，施密特），海Nectaris/窦Asperitatis（东经1220公里）是低Ti和VLT玄武岩物质最可能的来源（crater Theophilus，Madler，Torricelli），在蒸汽海附近有一个大的火山碎屑存款（西北约600公里）是最有可能的火山碎屑物质来源地区（尽管该地区没有明显的来源陨石坑）。
Abstract— We present the petrography and geochemistry of five 2–4 mm basalt fragments from the Apollo 16 regolith. These fragments are 1) a high‐Ti vitrophyric basalt compositionally similar to Apollo 17 high‐Ti mare basalts, 2) a very high‐Ti vitrophyric basalt compositionally similar to Apollos 12 and 14 red‐black pyroclastic glass, 3) a coarsely crystalline high‐Al basalt compositionally similar to group 5 Apollo 14 high‐Al mare basalts, 4) a very low‐Ti (VLT) crystalline basalt compositionally similar to Luna 24 VLT basalts, and 5) a VLT basaltic glass fragment compositionally similar to Apollo 17 VLT basalts. High‐Ti basalt has been reported previously at the Apollo 16 site; the other basalt types have not been reported previously. As there are no known cryptomaria or pyroclastic deposits in the highlands near the Apollo 16 site (ruling out a local origin), and scant evidence for basaltic material in the Apollo 16 ancient regolith breccias or Apollo 16 soils collected near North Ray Crater (ruling out a basin ejecta origin), we infer that the basaltic material in the Apollo 16 regolith originated in maria near the Apollo 16 site and was transported laterally to the site by small‐ to medium‐sized post‐basin impacts. On the basis of TiO2 concentrations derived from the Clementine UVVIS data, Mare Tranquillitatis (˜300 km north) is the most likely source for the high‐Ti basaltic material at the Apollo 16 site (craters Ross, Arago, Dionysius, Maskelyne, Moltke, Sosigenes, Schmidt), Mare Nectaris/Sinus Asperitatis (˜220 km east) is the most likely source for the low‐Ti and VLT basaltic material (craters Theophilus, Madler, Torricelli), and a large regional pyroclastic deposit near Mare Vaporum (˜600 km northwest) is the most likely source region for pyroclastic material (although no source craters are apparent in the region).