Be-10 and Al-26 evidence for exceptionally low rates of Australian bedrock erosion and the likely existence of pre-pleistocene landscapes
Be-10 and Al-26 evidence for exceptionally low rates of Australian bedrock erosion and the likely existence of pre-pleistocene landscapes
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DOI：
10.1006/qres.1995.1082
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发表时间：
1995-11-01
影响因子：
2.3
通讯作者：
Turner, J
中科院分区：
文献类型：
--
作者：
Bierman, P;Turner, J
对原位生产的Be-10和Al-26的分析表明，一些澳大利亚的岩堡（花岗岩圆顶）是世界上最稳定的地貌表面之一，侵蚀速度低至0.6 m/myr。对10个样品的20次同位素分析表明，这些孤立的花岗岩圆顶的裸露基岩顶部已经暴露在至少0.5 myr的宇宙辐射中，并且侵蚀的平均模式速率小于0.7 +/- 0.1 m/myr （n = 6）。从武迪纳山、小武迪纳山和Yarwondutta岩采集的样品的同位素分析最符合侵蚀过程中的连续暴露，另一方面，从一些圆顶侧面和其他圆顶顶部采集的样品的同位素丰度表明了复杂的暴露历史，包括埋藏和再暴露。这些独特的同位素数据为评估这些神秘地貌的古老和发展提供了第一个定量信息，但以前未经验证，并表明一些艾尔半岛的冰山可能是前更新世景观的遗留物特征。(C) 1995年华盛顿大学。
Analysis of in situ-produced Be-10 and Al-26 demonstrate that some Australian inselbergs (granitic domes) are among the most stable geomorphic surfaces in the world, eroding at rates as low as 0.6 m/myr, Twenty isotopic analyses of ten samples suggest that the bare bedrock tops of these isolated granitic domes have been exposed to cosmic radiation for at least 0.5 myr and are eroding at a mean model rate less than 0.7 +/- 0.1 m/myr (n = 6). Isotopic analyses of samples collected from the top of Mt. Wudinna, Little Wudinna, and Yarwondutta Rock are most consistent with continuous exposure during erosion, On the other hand, samples collected from the flanks of some domes and the tops of other domes have isotopic abundances suggestive of complex exposure histories including burial and reexposure. These unique isotopic data provide the first quantitative information for evaluating longstanding, but previously untested, hypotheses regarding the antiquity and development of these enigmatic landforms and indicate that some Eyre Peninsula inselbergs are probably relict features of pre-Pleistocene landscapes. (C) 1995 University of Washington.