THE DUPAL ANOMALY AS A TRACE OF THE UPWELLING LOWER MANTLE
THE DUPAL ANOMALY AS A TRACE OF THE UPWELLING LOWER MANTLE
复制标题
DOI：
10.1038/336667a0
复制
发表时间：
1988-12-15
期刊：
影响因子：
64.8
通讯作者：
CASTILLO, P
中科院分区：
文献类型：
--
作者：
CASTILLO, P
现在人们普遍认为地球的地幔是同位素不均匀的，但这种不均匀性的规模和分布以及整个地幔的结构和演化却知之甚少。“杜帕尔异常”1，2与这个问题有着重要的关系，因为它是迄今为止在地球表面划定的最大的同位素域，并且被证实2在地球历史的早期就形成了。在这里，我表明，这两个Dupal异常极大值似乎是密切相关的两个大规模的低地震速度在下地幔3，这反过来又与活跃的热点的位置。这种相关性提出了下地幔中的大规模结构特征在地球表面产生地球化学印记的可能性。因此，这种相关性可能会对地幔的化学结构和地幔对流的性质产生严重的限制。
It is now widely accepted that the Earth's mantle is isotopically heterogeneous, but the scale and distribution of this heterogeneity and the structure and evolution of the mantle as a whole are poorly understood. The 'Dupal anomaly'1,2has an important bearing on this problem because it is the largest isotopic domain yet delineated on the Earth's surface and it is suggested2to have been formed early in the Earth's history. Here I show that the two Dupal anomaly maxima appear to be closely associated with the two large-scale regions of low seismic velocity in the lower mantle3, which in turn are correlated with the loci of active hotspots. This correlation raises the possibility that large-scale structural features in the lower mantle produce geochemical imprints on the Earth's surface. Thus, the correlation may place severe constraints on the chemical structure of the mantle and the nature of mantle convection.