On some consequences and possible causes of layered mantle convection
On some consequences and possible causes of layered mantle convection
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层状地幔对流的一些后果和可能的原因
DOI：
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
D. McKenzie
中科院分区：
文献类型：
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作者：
F. Richter;D. McKenzie
采用室内实验和数值实验对离散层内对流进行了研究。实验室实验，主要使用甘油溶液的含水量作为建立“化学”密度变化的一种方式，表明当层之间的化学密度对比大于与对流系统内最大温差相关的密度变化时，对流将仍然局限于叠加层。数值实验表明，在层与层之间的界面处存在双热边界层，如果按照最近的地球化学模型的建议将下地幔隔离，这一特征将导致地幔在700 km深度附近平均温度升高约500°C。层状地幔对流系统的可能原因包括主元素化学变化、主元素化学和相变的联合作用，或者在Clapeyron斜率足够负的情况下仅发生相变。
Laboratory and numerical experiments are used to study convection confined to discrete layers. The laboratory experiments, which use the water content of a predominantly glycerine solution as a way of establishing ‘chemical’ density variations, show that convection will remain confined to superimposed layers when the chemical density contrast between layers is greater than the density change associated with the greatest temperature difference within the convecting system. The numerical experiments show a double thermal boundary layer at the interface between layers, a feature that would result in an average temperature increase of about 500°C in the mantle near 700-km depth if the lower mantle is isolated as suggested by recent geochemical models. The possible causes of a layered mantle convection system include major element chemistry variations, the combined effect of major element chemistry and a phase change, or a phase change alone if it has a sufficiently negative Clapeyron slope.