Oligocene-Miocene age of aridity in the Atacama Desert revealed by exposure dating of erosion-sensitive landforms
Oligocene-Miocene age of aridity in the Atacama Desert revealed by exposure dating of erosion-sensitive landforms
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DOI：
10.1130/g21184.1
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发表时间：
2005-04-01
期刊：
影响因子：
5.8
通讯作者：
Juez-Larré, J
中科院分区：
文献类型：
--
作者：
Dunai, TJ;López, GAG;Juez-Larré, J
智利阿塔卡马沙漠超干旱发生的年龄迄今为止一直不确定，需要验证地质和气候学概念。对智利北部侵蚀敏感沉积物表面碎屑中宇宙成因 Ne-21 的测量表明，自 25 Ma 以来，这些表面几乎没有受到侵蚀的影响。沉积物碎屑的表面暴露年龄给出了 25、20 和 14 Ma 的重复值以及 37 和 9 Ma 的单独值。需要极度干旱的条件来保护地球上这些最古老的连续暴露的表面。我们的发现与这样的假设相一致：阿塔卡马沙漠的干旱可能是安第斯山脉高地隆起的原因，而不是结果。
The age of onset of hyperaridity in the Atacama Desert, Chile, which is needed to validate geological and climatological concepts, has been heretofore uncertain. Measurement of cosmogenic Ne-21 in clasts from erosion-sensitive sediment surfaces in northern Chile shows that these surfaces have been barely affected by erosion since 25 Ma. Surface exposure ages of sediment clasts give replicate values at 25, 20, and 14 Ma and individual values at 37 and 9 Ma. Predominantly hyperarid conditions are required to preserve these oldest continuously exposed surfaces on Earth. Our findings are compatible with the hypothesis that the onset of aridity in the Atacama Desert could be the reason for, rather than the consequence of, uplift of the high Andes.