Comment on “Apatite 4He/3He and (U-Th)/He Evidence for an Ancient Grand Canyon”
Comment on “Apatite 4He/3He and (U-Th)/He Evidence for an Ancient Grand Canyon”
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对“磷灰石 4He/3He 和 (U-Th)/He 古代大峡谷的证据”的评论
作者：
K. Karlstrom;John P. Lee;S. Kelley;R. Crow;R. Young;I. Lucchitta;L. Beard;R. Dorsey;J. Ricketts;W. Dickinson;L. Crossey
Flowers和Farley（报告，2012年12月21日，第1616页；2012年11月29日在线发表）提出大峡谷有7000万年的历史。大峡谷年龄的鲜明对比模型——70万年和600万年——可以通过2500万到1500万年前在大峡谷东部雕刻的一个浅古峡谷来调和，否定了提出的70万年和55万年古峡谷。冷却模式和地质资料最符合大峡谷西部和大理石峡谷的5 ~ 6 Ma年龄。
Flowers and Farley (Reports, 21 December 2012, p. 1616; published online 29 November 2012) propose that the Grand Canyon is 70 million years old. Starkly contrasting models for the age of the Grand Canyon—70 versus 6 million years—can be reconciled by a shallow paleocanyon that was carved in the eastern Grand Canyon 25 to 15 million years ago (Ma), negating the proposed 70 Ma and 55 Ma paleocanyons. Cooling models and geologic data are most consistent with a 5 to 6 Ma age for western Grand Canyon and Marble Canyon.