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Arrowhead housed at Bern History Museum found to be made from meteoritic iron
An international team of geologists and historians has found that an arrowhead housed at the Bern History Museum was made using meteoritic iron. In their paper published in Journal of Archaeological Science, the group describes the attributes of the arrowhead and where they believe the material it was made of came from.
Prior research has shown that meteoritic iron was used by early people in many parts of the world, from Eurasia to the Middle East and Africa. Notably, researchers have found few examples of use of meteoric iron by early people in Europe. Suspecting that many such artifacts have been found but not identified as such, the team on this new effort conducted a search of archaeological collections at various sites in Switzerland.
Testing of an arrowhead found at the Bern History Museum showed it was made partly of aluminum-26 isotopes, which are not found naturally on Earth. They also found an iron and nickel alloy that has only ever been detected in meteorites.
In checking its history, the team found that the arrowhead had been discovered at what had once been a Bronze Age site called Mörigen. A community of early people had lived there during the years 900 to 800 BCE.
The team also found remnants of an adhesive on the arrowhead, which they guessed to be tar pitch, suggesting that the arrowhead had been attached to a shaft of some sort.
The researchers noted that the site where the arrowhead was found is less than eight kilometers from the point where the Twannberg meteorite crashed into the ground, making it the likely source of the iron used to make the arrowhead. But upon closer inspection, the team found that the concentrations of germanium and nickel did not match. That led them to look for another source.
A search of a geological database showed that only three meteorites with the right combination of metals had been found in Europe: one in the Czech Republic, another in Spain, and the third in Estonia. The research team suggests that the one in Estonia was the most likely source for the arrowhead they studied—an example of the extensive trade network that was active during the Bronze Age in Central Europe.
注释：
meteoritic: adj
表示" 陨星的"，means "of or relating to or caused by meteorites"，如：meteoritic iron 陨铁 meteoritic sample 陨石样品
Eurasia
表示"欧亚大陆"，means "the land mass formed by the continents of Europe and Asia"，如：Any of various predatory carnivorous canine mammals of North America and Eurasia that usually hunt in packs.北美洲和欧亚大陆的各种掠夺型犬科食肉哺乳动物，通常成群捕食。artifact: n
表示" 人工制品；史前古器物"，means "a man-made object taken as a whole"，如：These artifacts can be the spoils of war, unlike gold and equipment. 这些史前古器物会在战争中受损，而不像金币和装备一样。
Isotope: n
表示"同位素"，means "one of two or more atoms with the same atomic number but with different numbers of neutrons"，如：Changes of nuclear mass and nuclear size cause isotope shifts.原子核质量和大小的不同引起同位素移动。
remnant: n; adj
1. n表示" 残余"，means "a part that remains"，如：I will sell this remnant to you, at cost.我愿将此剩货照成本卖给你。
2. adj表示" 剩余的"，means "remaining"，如：The beautiful curtain is made of remnant materials. 这个漂亮的窗帘是用零头布做的。
tar: n
1. n表示" 焦油； 柏油"，如：This kind of tobacco has a high tar content. 这种香烟焦油含量很高。
2. v表示" 涂以焦油"，如：I had to tar the driveway in the afternoon. 我得在下午把车道涂上柏油。
germanium: n
表示" [化]锗"，如：Germanium has higher electric conductivity than silicon. 锗的导电率比硅高。
Estonia: n
表示" 爱沙尼亚"，means "a republic in northeastern Europe on the Baltic Sea"，如：The alarm is sounding well beyond Estonia. 网络安全的警示声在爱沙尼亚外的其它地区也得到了响应。
中文简要说明：
瑞士伯尔尼历史博物馆收藏的一枚距今大约3000年的古人武器，最近由跨国研究团队查明材质为「陨铁」，亦即这件武器使用的材料来自外层空间，主成分包括铁、镍、铝，而且可能由欧洲先民取道青铜器时代的贸易路线从波罗的海一带运抵现今出土地点，旅途超过2200公里。研究成果已发表于《考古科学期刊》（Journal of Archaeological Science）。
综合科学新闻网站Phys.org、英国《每日邮报》报导，这枚古老的武器呈箭头状，由伯尔尼大学研究人员在瑞士西北部默里根（Mörigen）一处青铜器时代遗址发现。公元前900年至公元前800年期间，当地曾有人类成群居住。
以往有研究显示，从欧亚大陆到中东、非洲，世界上许多地区的先民都用过陨铁（meteoritic iron）制物。在瑞士这枚箭器查明材料来源之前，欧洲已有2件类似发现：波兰曾出土陨铁材质手镯与斧头各一。学界怀疑中欧与西欧可能藏有多种这类具有重大意义的历史文物。
这枚陨铁箭器长度约1.5吋（3.81公分），重量仅0.102盎司（约2.89克），19世纪在比尔湖（Lake of Biel）发现之后就送进伯尔尼史博馆，后来科学家才又翻出来研究。地质学家检测发现其成分之一是铝-26（aluminum-26）。铝-26是早期太阳系大量存在、半衰期较短的同位素，不过，地球上并无天然存在的铝-26。
研究团队利用多种方法检测其成分组合，包括电子显微镜、X光、高能辐射等分析。箭器的尖端成分包含一种铁镍合金，这种合金此前仅发现于自外层空间坠入地球的陨石。箭头部位也发现某种黏着剂的残留物，研究团队猜测可能是来自于某种木材的焦油，这代表箭头曾与某种柄状物接合。
这枚古物出土地点距离瑞士知名陨石坠落处特万贝格（Twannberg）不到8公里。研究团队起初分析陨铁出自特万贝格陨石，这块瑞士境内发现体积最大的陨石约16万年前坠落地球。但团队仔细分析发现，锗、镍浓度不符，于是另觅可能来源。
地质数据数据显示，具有完全相同成分组合、在同一段时间坠落于欧洲的陨石只有3块，分别位于捷克、西班牙、爱沙尼亚。研究团队认为，伯尔尼史博馆的箭形铁器材料来源以3500年前坠落于爱沙尼亚的陨石最有可能，坠落地点距离瑞士约1400哩（约2253公里）；现今爱沙尼亚与瑞士之间可能有贸易网存在，古人得以从波罗的海换得武器，交易货物除了陨铁，还包括琥珀、燧石等。这枚陨铁箭头或许就是青铜器时代中欧广大贸易网曾经活络的例证，研究团队正持续搜寻更多文物以证明这条路线一度存在。
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