地震地质 ›› 1988, Vol. 10 ›› Issue (3): 88-92.

• 科研简报 • 上一篇    下一篇

冀东太古宙麻粒岩及下地壳分层的讨论

吴宗絮   

  1. 国家地震局地质研究所
  • 收稿日期:1987-08-31 出版日期:1988-09-07 发布日期:2009-11-25
  • 基金资助:
    国家地震局科学基金的资助

ARCHAEAN GRANULITE AND SUBDIVISION OF LOWER CRUST IN EASTERN HEBEI, CHINA

Wu Zong-xu   

  1. Institute of Geology, State Seismolotical Bureau
  • Received:1987-08-31 Online:1988-09-07 Published:2009-11-25

摘要: 本文提出冀东太古宙麻粒岩可划分为无角闪石或黑云母的辉石亚相和含角闪石或黑云母的角闪石亚相,基于平衡的矿物组合估计的压力和温度,辉石亚相和角闪石亚相分别为800-850℃,9-11kbar,700—-750℃,7-9kbar。由麻粒岩亚相推导的冀东下地壳由二层构成,下部层(30-37公里)为辉石亚相,上部层(23-30公里)为角闪石亚相,它与地球物理资料相符合。

关键词: 河北, 麻粒岩相, 下地壳分层

Abstract: Archaean granulite in eastern Hebei may be divided into pyroxene and hornblende-granulite subfacies. depending on whether they contain hornblende or biotite or not. Based on the mineral equilibrium assemblage, the estimated P-T of pyroxene and hornblende subfacies are 800-850℃, 9-11 kbars and 700-750℃, 7-9 kbars, respectively. The lower crust inferred from the granulite subfacies in eastern Hebei may consist of two layers, the lower one (30-37 km) consists of pyroxene granulite subfacies and upper(23 -30 km) of hornblende granulite subfacies. This suggestion is consistent with geophysical data. The occurrence of the upper mantle spinel in the pyroxene subfacies supports the suggestion of pyroxene subfacies for the lower layer of the lower crust.

Key words: Hebei, Granulite fades, Subdivision of lower crust