原始地壳
- 网络primitive crust
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早太古代以前(大于3000Ma),本区已发育了成分不均匀的原始地壳,后期表壳岩系沉积在这种地壳的裂谷当中并发生了麻粒岩相变质作用;
Before the early Archaean ( > 3 000Ma ), the chemically heterogeneous original crust had been developed .
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将区内构造演化归纳为太古早元古代原始地壳形成、中新元古代大陆地壳裂解、震旦三叠纪板块构造体制、中新生代陆内造山等四个演化阶段。
Four tectonic evolution phases have been made out in this area . They are original crust formed in the Archean-Early Proterozoic era , continental crust shearing in the middle-new Proterozoic era , plate tectonic developed in Sinian-Triassic period and intracontinental orogeny in the Middle Cenozoic period .
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岩性和岩石化学特征表明,区内玄武岩为碱性&钙碱性拉斑玄武岩。同位素地球化学和稀土元素分布模式研究资料表明,本区玄武岩原始岩浆来源于地壳和地幔二元组分相混合的体系。
From the isotopic geochemistry and the model of REE distribution analysis , it can be determined that the original magma was the result from partial crust with contamination of upper mantle .