Age and composition of oxalate-rich crusts in the northern territory, Australia
Age and composition of oxalate-rich crusts in the northern territory, Australia
复制标题
澳大利亚北部地区富含草酸盐结壳的年龄和成分
DOI：
10.1179/sic.1991.36.1.24
复制
发表时间：
1991
影响因子：
0.8
通讯作者：
A. Watchman
中科院分区：
文献类型：
--
作者：
A. Watchman
摘要介绍了澳大利亚富石英岩石中一些厚重的多层富草酸盐结壳的性质、成因和时代，以期提醒修复人员和文物保护人员注意它们在古环境和岩石艺术测年研究中的价值。矿物学和地球化学数据以及野外观测和剖面分析的证据表明，这些矿床是雨水中的有机酸与附着在稳定的硅质岩架和其他遮蔽面上的富钙尘埃颗粒发生化学反应而自然形成的。对地表结壳中发现的草酸盐矿物的碳-14测年结果表明，形成富含草酸盐的地表沉积物的自然过程已经持续了数千年。这种草酸盐层的测年为建立不同史前绘画风格的时间框架提供了一种手段；该方法没有给出个人和地区的直接年龄。
AbstractThe nature, origin and age of some thick multi-layered oxalate-rich crusts from quartz-rich rocks in Australia are presented, with a view to alerting restorers and conservators to their value in palaeo-environmental and rock art dating studies. Mineralogical and geochemical data, together with field observations and evidence from cross-section analysis, suggest that these deposits are formed naturally by chemical reaction of organic acids in rainwater acting on calcium-rich dust particles which have accreted on stable siliceous rock ledges and other sheltered surfaces. Carbon-14 dating of the oxalate mineral, whewellite, found in the surface crusts ranges from modern to 8800 years BP: evidence that the natural processes which form oxalate-rich surface deposits have been continuous for many thousands of years. Such dating of oxalate layers provides a means for establishing time-frames in which different prehistoric painting styles can be fixed; the method does not give a direct age for individual a...
与内皮细胞共培养的嗜酸性粒细胞具有增加的存活率和功能特性。
DOI：
10.1126/science.3110954
发表时间：
1987
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Rothenberg,ME;OwenJr,WF;Silberstein,DS;Soberman,RJ;Austen,KF;Stevens,RL
通讯作者：
Stevens,RL