早前寒武纪洋壳的地质记录及其板块构造意义

元古宙蛇绿岩的不断发现表明威尔逊旋回至少在早元古代已经明显起作用，部分太古宙绿岩带由不同的构造单元拼合而成，并发育不同于显生宙蛇绿岩的大洋壳岩石组合，地幔柱在早太古代构造演化过程中起重要作用，是板块构造的重要补充机制，地球早期热产量较高，可能是造成板块规模较小，洋壳较厚，板块运动速度较快的原因，并以缓倾角俯冲为特征。

GEOLOGICAL RECORD OF EARLY PRECAMBRIAN OCEANIC CRUST AND ITS IMPLICATION FOR PLATE TECTONICS

In recent years, many Proterozoic ophiolites are identified,which indicate that modern plate tectonics could be extrapolated at least to the Early Proterozoic, and Wilson cycle has been operated since then. Some Archean greenstone belts represent collages of allochthonous fragments, among which oceanic crust slices are identified with characteristics distinct from the Phanerozoic ophiolites. Archean komatiites tholeiites are commonly associated with the hot spots within the continental or oceanic lithosphere, generated by the mantle plume, originated from the deep thermal boundary layer in the mantle. In Archean, mantle plume played an important role in the tectonic evolution,which is also a major complementary mechanism for plate tectonics. Moreover, the scale of plates was smaller, oceanic crust was thicker than present,transporting rates of plate were higher owing to higher heat production in Archean. The gently dipping subduction might be dominated in early Archean.