Cohen B A, Swindle T D, Kring D A
The University of Arizona, Tucson, AZ 85721, USA.
Science. 2000 Dec 1;290(5497):1754-6. doi: 10.1126/science.290.5497.1754.
Lunar meteorites represent a more random sampling of lunar material than the Apollo or Luna collections and, as such, lunar meteorite impact melt ages are the most important data in nearly 30 years with which to reexamine the lunar cataclysm hypothesis. Within the lunar meteorite breccias MAC 88105, QUE 93069, DaG 262, and DaG 400, seven to nine different impact events are represented with 40Ar-39Ar ages between 2.76 and 3.92 billion years ago (Ga). The lack of impact melt older than 3.92 Ga supports the concept of a short, intense period of bombardment in the Earth-moon system at approximately 3.9 Ga. This was an anomalous spike of impact activity on the otherwise declining impact- frequency curve.
月球陨石比阿波罗或月球号采集的样本更能随机地代表月球物质，因此，月球陨石撞击熔体年龄是近30年来重新审视月球灾变假说的最重要数据。在月球陨石角砾岩MAC 88105、QUE 93069、DaG 262和DaG 400中，代表了7至9次不同的撞击事件，其40Ar-39Ar年龄在27.6亿至39.2亿年前（Ga）之间。年龄超过39.2 Ga的撞击熔体的缺失支持了在约39亿年前地月系统中存在一个短暂而强烈的撞击期的概念。这是在原本下降的撞击频率曲线上的一次异常撞击活动高峰。
