Aeolian contribution to strontium and strontium isotope variations in a Tasmanian speleothem
Aeolian contribution to strontium and strontium isotope variations in a Tasmanian speleothem
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DOI：
10.1016/s0009-2541(98)00035-7
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发表时间：
1998-07-10
期刊：
影响因子：
3.9
通讯作者：
Hawkesworth, C
中科院分区：
文献类型：
--
作者：
Goede, A;McCulloch, M;Hawkesworth, C
来自塔斯马尼亚州中南部的洞穴化石显示出锶含量的显著长期变化。元素呈明显的双峰型分布，两个模组之间的突变被认为是由于主导强风方向的快速变化，洞穴中的锶同位素组成在0.70865-0.70898之间，表明锶至少来自两个不同的来源；第一个元素来自上覆石灰岩，第二个元素具有较高的锶-87/锶-86组分，可能代表来自陆地尘埃的输入。洞穴记录是不同寻常的，因为它表明在冰间时期比在全冰川条件下输入的放射性锶粉尘通量更大，如果世界其他内陆洞穴遗址洞穴洞穴中所含的一些锶的风成来源得到证实，锶同位素组成的变化将提供第四纪期间陆地尘埃通量变化的高分辨率记录。在近海地区，相当数量的锶可能来自海相，在这些地区，洞穴中元素的时间变化至少部分地反映了由于海平面的变化而与海岸的距离的变化。(C)1998 Elsevier Science B.V.，保留所有权利。
A speleothem from south-central Tasmania shows marked secular variations in its strontium content. The element exhibits a striking bimodal distribution pattern with abrupt changes between two modal groups that is believed to be due to rapid changes in the direction of the dominant strong winds, Strontium isotope compositions in the speleothem range from 0.70865 to 0.70898, indicating derivation of Sr from at least two distinct sources; the first a persistent one from the overlying limestone, the second a higher Sr-87/Sr-86 component,probably representing input from terrestrial dust. The speleothem record is unusual because it indicates a greater input of radiogenic Sr dust flux during interstadial times than under full-glacial conditions, If an aeolian origin of some of the strontium contained in speleothems at other inland cave sites around the world can be confirmed, variations in strontium isotope composition will provide high-resolution records of how terrestrial dust flux has varied during the Quaternary. In near-coastal sites, significant amounts of strontium may be derived from seasalt and in those areas temporal variation of the element in speleothems may reflect, at least in part, changing distance from the coast due to changes in sealevel. (C) 1998 Elsevier Science B.V, All rights reserved.