月球隕石
受撞擊從月球落到地球的岩石
月球隕石是遭受小行星撞擊從月球飛濺出來並隕落到地球上的岩石,是研究月球物質成分和演化歷史的重要對象。除了少量具有結晶結構的岩石類型以外,大部分月球隕石為碎屑岩,這些碎屑岩主要有三類:高地斜長質角礫岩、月海玄武質角礫岩和高地斜長質-月海玄武質混合角礫岩。
第一個月球隕石ALHA 81005發現於1982年,月球隕石為研究月球物質成分和演化歷史提供了重要的樣品補充,在全面了解月球岩石種類、月球表面稀有氣體成分、鬆散月壤如何成為固結的岩石、月球表面受衝擊歷史等方面也具有重要意義。
當大的小行星體或慧星撞擊月球表面時,其表面物質的噴射可以達到逃逸月球的速度(2.4km/s)從而進入宇宙空間,其中一部分為地球所捕獲並降落到地球上,這表明月球隕石與月球表面的衝擊成坑事件密切相關,特別是大的小行星體低角度撞擊更有利於噴射物質的逃逸。由於月球經過岩漿分異作用,所以月球隕石屬無球粒隕石。
月球隕石的發現開始於20世紀80年代。在Apollo和Luna計劃採樣返回10年之後,於1982年才確認第一塊月球隕石ALHA 81005。這塊隕石是美國隕石考察隊(ANSMET)在南極Alan Hill山區發現的,該隕石樣品被送往美國休斯頓空間中心進行處理和保管,由於該中心負責月球樣品處理和保管,研究人員熟悉月球樣品,他們在處理該樣品時發現其結構特徵與月球樣品非常相似,而促使他們考慮到ALHA 81005隕石可能來自月球。其實,在此樣品之前,日本南極考察隊在Yamato發現了一塊月球隕石Y791197,由於當時缺乏經驗,這塊隕石被誤認為是鈣長輝長無球粒隕石(Eucrite)。據確認時間順序,Y791197、Y82192和Y82193分別是第二、三、四塊月球隕石。此外,Y793169和EET87521隕石曾被誤認為是鈣長輝長無球粒隕石,後來被確認為月球隕石。
月球隕石稀少,發現過程非常緩慢。到1993年,才發現12塊月球隕石,而且主要來自南極,南極之外僅在澳大利亞發現一塊Calcalong Creek。到2000年,月球隕石數量達到了31塊,同樣,絕大部分來自於南極。由於Calcalong Creek隕石曾在市場上標價4萬美元/g,這激發了民間隕石愛好者對月球隕石的極大興趣,到1997年,在南極以外發現了第二塊月球隕石。2000年之後,民間在非洲沙漠地區尋找月球隕石取得了巨大成功,月球隕石數量和質量也隨著飆升。至2013年,已公布發現月球隕石165個,總重量65.2kg,如考慮成對隕石,這些隕石代表了81次隕石降落,其中10個月海玄武岩、50個斜長岩、21個玄武質斜長質混合角礫岩。在數量上,32(塊(成對19塊)月球隕石發現於南極,其他148塊發現於南極之外的沙漠地區。在數量上,沙漠月球隕石占月球隕石的絕大部分。
由於缺乏大氣層的保護,月球在歷史上經歷了強烈的撞擊作用,因此,月球上布滿了大大小小的撞擊坑,同時,在月球表面形成了一層數米至20多米厚度不等的月壤。與此相似,月球隕石除少量具有完整結晶結構玄武岩外,其餘大部分月球隕石均為碎屑岩。根據岩石結構和礦物組合,月球隕石可分為玄武岩、斜長岩和玄武岩-斜長岩質混合角礫岩等三類,這與月球岩石的月海玄武岩、高地斜長岩和過渡地區的混合角礫岩相對應。另外,根據岩石學和化學成分特徵,月球隕石主要有三種端元類型物質組成,即角礫岩化斜長岩、玄武岩和角礫岩化玄武岩、蘇長岩成分的衝擊熔融玻璃即月球岩石中的克里普岩。
玄武岩
玄武岩(總質量7640.3 g) | |||||
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No. | Name | Year Found | Rock Type | Mass (G) | Found |
B1 | Yamato 793169 | 1991 | Unbrecciated Basalt | 6.1 | Antarctica |
B2 | Asuka 881757 | 1989 | Gabbro | 442 | Antarctica |
B3 | Northwest Africa 032, 479 | 1999 | Unbrecciated Basalt | ~300, 156 | Africa |
B4 | Northeast Africa 003 | 2000 | Unbrecciated Basalt | 124 | Africa |
B5 | Northwest Africa 773, 2700, 2727, 2977, 3160, 3170, 6950, 3333, 7007, NWAAnoual | 2000, 2004, 2005 | Gabbro | 60, 6, 33, 1649, 5.9, 633, 31.7, 191.2, 233, 34 | Africa |
B6 | Dhofar 287 | 2001 | Unbrecciated Basalt | 154 | Asia |
B7 | LaPaz Icefield 02205, 02224, 02226, 02436, 03632, 04841 | 2002-2004 | Unbrecciated Basalt | 1226.3, 252, 244.1, 59.0, 93, 56 | Antarctica |
B8 | Miller Range 5035 | 2006 | Unbrecciated Basalt | 142 | Antarctica |
B9 | Northwest Africa 4898 | 2007 | Unbrecciated Basalt | 137 | Africa |
B10 | Northwest Africa 4734 | 2007 | Unbrecciated Basalt | 1372 | Africa |
斜長岩
斜長岩(總質量) | |||||
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No. | Name | Year Found | Rock Type | Mass (G) | Found |
F1 | Yamato 791197 | 1979 | Anorthositic Regolith Breccia | 52.4 | Antarctica |
F2 | Aspen Hills 81005 | 1982 | Anorthositic Regolith Breccia | 31.39 | Antarctica |
F3 | Yamato 82192, 82193, 86032 | 1982, 1986 | Anorthositic Fragmental Breccia | 37, 27, 648 | Antarctica |
F4 | MacAlpine Hills 88104, 88105 | 1989 | Anorthositic Regolith Breccia | 61, 663 | Antarctica |
F5 | Queen Alexandra 93069, 94269 | 1993 | Anorthositic Regolith Breccia | 21.4, 3.1 | Antarctica |
F6 | Dar al Gani 262, 996, 1042, 1048 | 1997, 1999, 2001 | Anorthositic Regolith Breccia | 513, 12.31, 801, 1 | Africa |
F7 | Dar al Gani 400, 1058 | 1998 | Anorthositic Regolith Breccia | 1815, 1425 | Africa |
F8 | Dhofar 081, 280, 910, 1224 | 2001, 2003 | Anorthositic Fragmental Breccia | 174, 251.2, 142, 4.57 | Asia |
F9 | Dhofar 025, 301, 304, 308 | 2000 | Anorthositic Regolith Breccia | 751, 9, 10, 2 | Asia |
F10 | Dhofar 026, 457, 458, 459, 460, 461, 462, 463, 464, 465, 466, 467, 468 | 2000, 2001 | Anorthositic Granulitic Breccia | 148, 99.5, 36.7, 31.5, 73.1, 33.7, 44.7, 24.3, 22.3, 70.7, 69.2, 36.2, 18.9 | Asia |
F11 | Northwest Africa 482 | 2001 | Anorthositic Impact Melt Breccia | 1015 | Africa |
F12 | Dhofar 302 | 2001 | Anorthositic impact-melt breccia | 3.83 | Asia |
F13 | Dhofar 303, 305, 306, 307, 309, 310, 311, 489, 730, 731, 908, 909, 911, 950, 1085 | 2003 | Anorthositic Impact Melt Breccia | 4.15, 34.11, 12.86, 50, 81.3, 10.8, 4, 34.4, 108, 36, 245(9), 3.9, 194(9), 21.7, 197(4) | Asia |
F14 | Dhofar 490, 1084 | 2003 | Anorthositic Fragmental Breccia | 34.05, 90 | Asia |
F15 | Dhofar 733 | 2002 | Anorthositic Granulitic Breccia | 98 | Asia |
F16 | Northeast Africa 1 | 2002 | Anorthositic Regolith Breccia | 262 | Africa |
F17 | Pecora Escarpment 2007 | 2003 | Anorthositic Regolith Breccia | 22.4 | Antarctica |
F18 | Northwest Africa 2200 | 2004 | Anorthositic Impact Melt Breccia | 552 | Africa |
F19 | Northwest Africa 3163, 4483, 4881, 6275 | 2005, 2010 | Anorthositic granulitic breccia | 208, 606, 1.0, 1634 | Africa |
F20 | Dhofar 1428 | 2006 | Anorthositic Granulitic Breccia | 213 | Asia |
F21 | Dhofar 1443, 1436 | 2001, 2004 | Anorthositic breccia | 36.7, 24.2 | Asia |
F22 | Northwest Africa 2998, 7262 | 2012, 2006 | Anorthositic breccia | 413, 163 | Africa |
F23 | Graves Nunataks 6157 | 2007 | Anorthositic Breccia | 0.8 | Antarctica |
F24 | Larkman Nunataks 6638 | 2007 | Anorthositic Breccia | 5.29 | Antarctica |
F25 | Northwest Africa 5000 | 2007 | Anorthositic Regolith Breccia | 11528 | Africa |
F26 | Northwest Africa 4936, 5406, 6221, 6355, 6470, 6570, 6687, 7190 | 2008, 2010, 2011, 2007 | Anorthositic Regolith Breccia | 109.4, 760, 96, 415, 42.4, 5.3, 172, 281 | Africa |
F27 | Sayh al Uhaymir 449 | 2008 | Anorthositic Impact Melt Breccia | 16.5 | Asia |
F28 | Sayh al Uhaymir 300 | 2004 | Polymict Impact Melt Breccia | 152.6 | Asia |
F29 | Northwest Africa 4932 | 2007 | Anorthositic Impact Melt Breccia | 93 | Africa |
F30 | Miller Range 7006 | 2007 | Anorthositic Regolith Breccia | 1.368 | Antarctica |
F31 | Shisr 160 | 2008 | Anorthositic regolith breccia | 101 | Asia |
F32 | Shisr 161 | 2008 | Anorthositic fragmental breccia | 57 | Asia |
F33 | Northwest Africa 5744 | 2009 | Anorthositic granulitic breccia | 170 | Africa |
F34 | Jiddat al Harasis 348 | 2008 | Anorthositic Regolith Breccia | 18.7 | Asia |
F35 | Shisr 162 | 2006 | Anorthositic impact melt breccia | 5530 | Asia |
F36 | Shisr 166 | 2008 | Anorthositic impact melt breccia | 128.8 | Asia |
F37 | Dhofar 1527 | 2009 | Anorthositic impact melt breccia | 42.6 | Asia |
F38 | Dhofar 1528 | 2009 | Anorthositic breccia | 213 | Asia |
F39 | Miller Range 090034, 090036, 090070, 090075 | 2009 | Anorthositic regolith breccia | 195.6, 245, 137.5, 143.5 | Antarctica |
F40 | Dhofar 1627 | 2010 | Anorthositic impact melt breccia | 86.1 | Asia |
F41 | Northwest Africa 6481 | 2010 | Anorthositic impact melt breccia | 13.7 | Africa |
F42 | Northwest Africa 6578 | 2010 | Anorthositic granulitic breccia | 1638 | Africa |
F43 | Dhofar 1673 | 2011 | Anorthositic breccia | 15.1 | Asia |
F44 | Northwest Africa 6721 | 2011 | Anorthositic fragmental breccia | 181 | Africa |
F45 | Northwest Africa 6888 | 2011 | Anorthositic regolith breccia | 208 | Western Sahara |
F46 | Northwest Africa 7022 | 2011 | Anorthositic fragmental breccia | 444 | Northwest Africa |
F47 | Dhofar 1669 | 2010 | Anorthositic breccia | 3.3 | Asia |
F48 | Northwest Africa 7274 | 2012 | Anorthositic breccia | 373 | Northwest Africa |
F49 | Northwest Africa 7493 | 2012 | Breccia | 503 | Africa |
玄武岩-斜長岩質混合角礫岩
玄武岩-斜長岩質混合角礫岩(19241.96 g) | |||||
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No. | Name | Year Found | Rock Type | Mass (G) | Found |
M1 | Yamato 793274, 981031 | 1980 | Anorthosite-bearing Basaltic Regolith Breccia | 8.7, 186 | Antarctica |
M2 | Elephant Moraine 87521, 96008 | 1988 | Basaltic or Gabbroic Fragmental Breccia | 31, 53 | Antarctica |
M3 | Calcalong Creek | 1990 | Basaltic-bearing Anorthositic Regolith Breccia | 19 | Australia |
M4 | Queen Alexandra 94281 | 1994 | Anorthosite-bearing Basaltic Regolith Breccia | 23.4 | Antarctica |
M5 | Kalahari 008, 009 | 1999 | Anorthositic Regolith / Basaltic Fragmental Breccias | 598, 13500 | Africa |
M6 | Yamato 983885 | 1999 | Basalt-bearing Anorthositic Regolith Breccia | 290 | Antarctica |
M7 | Meteorite Hills 1210 | 2001 | Anorthosite-bearing Basaltic Fragmental Breccia | 22.8 | Antarctica |
M8 | Sayh al Uhaymir 169 | 2002 | Basalt-bearing Anorthositic Regolith Breccia | 206.45 | Asia |
M9 | Dhofar 925, 960, 961 | 2003 | Basalt-bearing Anorthositic Impact Melt Breccia | 49, 35.4, 21.6 | Asia |
M10 | Northwest Africa 3136 | 2004 | Anorthosite-bearing Basaltic Regolith Breccia | 95.1 | Africa |
M11 | Dhofar 1180 | 2005 | Basalt-bearing Anorthositic Fragmental Breccia | 121 | Asia |
M12 | Northwest Africa 2995, 2996, 3190, 4503, 5151, 5152, 6252, 6554, 6555 | 2005-2010, 2005 | Basalt-bearing Anorthositic Fragmental Breccia | 113, 138, 29.7, 538, 984, 41, 70, 289, 38 | Africa |
M13 | Northwest Africa 4472, 4485 | 2006 | Anorthosite-bearing Basaltic Breccia | 64.3, 188 | Africa |
M14 | Northwest Africa 4884 | 2007 | Anorthosite-bearing Basaltic Regolith Breccia | 42 | Africa |
M15 | Northwest Africa 4819 | 2007 | Anorthositic regolith breccia | 234 | Africa |
M16 | Dhofar 1442 | 2005 | Anorthositic regolith breccia | 106.5 | Asia |
M17 | Northwest Africa 5207 | 2007 | Anorthositic fragmental breccia | 101 | Africa |
M18 | Northwest Africa 5153 | 2007 | Anorthositic fragmental breccia | 50 | Africa |
M19 | Lynch 2 | 2010 | Breccia | 36.5 | Western Australia |
M20 | Dhofar 1629 | 2007 | Breccia | 2.51 | Asia |
M21 | Northwest Africa 7611 | 2012 | Basalt-bearing feldspathic fragmental breccia | 916 | Africa |
2020年4月30日,世界上最大的月球隕石之一將在佳士得拍賣行進行私人拍賣,估價為200萬英鎊。這塊月球隕石重達13.5公斤,它被稱為NWA 12691,被認為是地球上發現的第五大月球隕石。