The nature of the Mohorovicic discontinuity
The nature of the Mohorovicic discontinuity
复制标题
莫霍洛维奇不连续面的性质
DOI：
10.1029/tr039i005p00947
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发表时间：
1958
期刊：
影响因子：
--
通讯作者：
J. Lovering
中科院分区：
文献类型：
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作者：
J. Lovering
原始陨石体的硅酸盐地幔成分的新证据表明，地球上地幔的相当一部分可能是由玄武岩成分的硅酸盐材料组成的。因此，莫霍洛维奇不连续面可能不会将玄武质地壳物质与超基性上地幔物质分开，而是标志着一个区域，在该区域中玄武质物质正在转化为可能由岩石型榴辉岩代表的高压变质。对大洋和大陆下莫霍罗维界面平均水平的温度和压力的估计给出了玄武岩→榴辉岩转变的“平衡线”上的两个点，其大致关系为p = 21.80 - 488（p以巴为单位，9以°C为单位）。这一假设的地球物理后果是深远的。它消除了所观察到的海洋和大陆热流的等效性所产生的困难，提供了令人满意的“母岩浆”，地壳中的花岗岩和玄武岩区已经分化，并提出了一种机制，通过简单地增加或降低该地区下方莫霍洛维奇不连续面的温度来升高或降低地球表面的地区。
New evidence for the composition of the silicate mantle of the primary meteorite body suggests that a considerable portion of the Earth's upper mantle may well be composed of silicate material of basaltic composition. Consequently the Mohorovicic discontinuity may not separate basaltic crustal material from ultrabasic upper-mantle material but rather mark a zone in which basaltic material is transforming into a high-pressure modification possibly represented by the rock-type eclogite. Estimates of the temperatures and pressures at the average levels of the Mohorovicic discontinuity under oceans and continents give two points on the ‘equilibrium line’ for the transformation basalt → eclogite which is roughly given by the relationship p = 21.80 — 488 (p in bars, 9 in °C). The geophysical consequences of this hypothesis are far reaching. It removes difficulties arising from the observed equivalence of oceanic and continental heat flows, provides satisfactory ‘parent magma’ from which the granitic and basaltic zones in the crust have differentiated, and suggests a mechanism for elevating or depressing regions of the Earth's surface simply by increasing or decreasing the temperature at the level of the Mohorovicic discontinuity beneath that region.