Archaean greenstone belts may include terrestrial equivalents of lunar maria
Archaean greenstone belts may include terrestrial equivalents of lunar maria
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太古宙绿岩带可能包括相当于陆地的月海
DOI：
10.1016/0012-821x(72)90172-0
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发表时间：
1972
影响因子：
5.3
通讯作者：
D. Green
中科院分区：
文献类型：
--
作者：
D. Green
一些太古宙绿岩带的火山序列下部包含了在1600-1650°C地球表面挤压的超镁铁质液体结晶的成员。这些液体被解释为地幔源成分60-80%熔融的产物，这意味着比古生代、中生代或近代壳幔动力学中得到的地幔熔融更具灾难性。这种情况可能是原始地球表面受到重大影响的结果。月球海陆盆地的形成对地球产生了类似的影响，并在地壳和上地幔早期化学分异中发挥了重要作用。提出了一种假设，认为一些太古宙绿岩带被解释为非常大的撞击伤痕，最初充满了撞击引发的超镁铁质至基性成分的熔体，随后随着进一步的岩浆作用、变形和变质作用演变成现在的太古宙绿岩带。
The lower portions of the volcanic sequence of some Archaean greenstone belts include members with crystallized from ultramafic liquids extruded at the earth's surface at 1600–1650°C. These liquids are interpreted as products of 60–80% melting of their mantle source composition which implies more catastrophic conditions of mantle melting than obtained in Palaeozoic, Mesozoic or Recent crust-mantle dynamics. Such conditions may be a consequence of major impacts on the surface of the primitive earth. It is suggested that the production of the lunar maria basins was accompanied by similar impacts on the earth and that such terrestrial maria played an important role in early stages of chemical differentiation of the crust and upper mantle. An hypothesis is presented in which some Archaean greenstone belts are interpreted as very large impact scars, initially filled with impact-triggered melts of ultramafic to mafic composition and thereafter evolving with further magmatism, deformation and metamorphism to the present Archaean greenstone belts.