| 1 | Cosmic-ray exposure age of Martian meteorite GRV 99027显示文摘We have determined the concentrations of 10Be and 26Al in GRV 99027 recovered by the 16th Chinese Antarctic expedition team, which are 14.1 ± 0.6 dpm/kg and 67.5 ± 3.4 dpm/kg, respectively. From the concentration of 10Be, we calculate a cosmic-ray exposure age of 4.4 ± 0.6 Ma for GRV 99027. The concentration of 26Al is too high compared to the 10Be exposure age, indicating extra production from solar ray. The exposure ages, petrologic and geochemical characteristics of mantle-derived Martian meteorites GRV 99027, LEW 88516, Y-793605, NWA 1950 and ALHA77005 are very similar, suggesting that these meteorites most probably were ejected from Mars in the same impact event. | D. FABEL R. BROWN S. FREEMAN | 2007 | Science China Earth Sciences2007，50，10： | 8 |
| 2 | 冰缘沉积物补给的减少会使裂点后退变慢吗?显示文摘在有相对基准面下降良好约束记录的苏格兰西部的4条河流中,冰后期基岩侵蚀的速率可以通过测量溯源裂点以下侵蚀宽谷阶地原地宇宙成因10Be浓度确定。10Be暴露年龄的沿程坡降显示两个不同的趋势:向上游趋于年轻和一致的年龄,对此我们解释为裂点后退和扩散搬运限制性下切的结果。我们发现,开始基岩河床下切和宽谷阶地的区域发育始于末次冰消期(距今11.5ka)不久,裂点后退速率在早—中全新世达到最大,之后不断下降达两个数量级,在晚全新世降到一个与单位河床面积流能无关的低速率。我们推断这种区域性的冰后期裂点后退变缓是全新世期间冰缘沉积物补给逐渐减少、导致基岩侵蚀缺乏'工具'的结果。我们的研究结果表明,主河流侵蚀时期可能与冰川旋回一致,冰期—间冰期过渡之后沉积物的减少可能是冰川作用区河流基岩侵蚀速率变化的重要原因。 | J. D. Jansen D. Fabel P. Bishop S. Xu C. Schnabel A. T. Codilean 孙昌斌(译) 李德文(校) | 2011 | 世界地震译丛2011，42，4： | 0 |
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