地震地质 ›› 1981, Vol. 3 ›› Issue (1): 41-50.

• 科研简报 • 上一篇    下一篇

中国东部新生代玄武岩中二辉橄榄岩团块的结构和组构

何永年, 林传勇   

  1. 国家地震局地质研究所
  • 收稿日期:1979-11-01 出版日期:1981-03-04 发布日期:2009-11-25

ON THE TEXTURE AND FABRIC OF SOME LHERZOLITE NODULES IN CAINOZOIC BASALT FROM EASTERN CHINA

He Yongnian, Lin Chuanyong   

  1. Institute of Geology, National Bureau of Seismology
  • Received:1979-11-01 Online:1981-03-04 Published:2009-11-25

摘要: 本文对中国东部一些新生代玄武岩中二辉橄榄岩团块的结构进行了研究。划分出了粗粒、残碎斑状和粒状变晶等三种主要结构类型,并对不同结构类型团块的组构进行了测定和研究,确定出粗粒—残斑—粒状变晶之过渡系列。认为上地幔普遍存在有塑性流动,初步探讨中国东部新生代时期的不同应力状态。

Abstract: The ultramafic nodules widely distributed in Cainozoic basalt in eastern China are regarded as fragments of upper mantle that were brought up to the ground surface by basaltic magma. It is suggested that the study of this kind of nodules would offer some direct information about upper mantle. The textures of some spinel lherzolite nodules collected from some regions in eastern China were discussed in this paper. Three main types of texture can be distinguished, such as coarse granular, porpbyroclastic and granuloblastic. Their fabrics were also analysed. And the preferred orientation of minerals indicates that the coarse granular type is lacking in orientation, whereas the porphyroclastic type has distinct orientation, and the lalter’s fabric feature is followed by the granuloblastic type with some variation. Thus, the coarse granular-porphyroclastic-granulobla-stic transitional sequence has been established. Moreover, the textures and fabrics of Alpine type of peridotite from a suite of ophiolite formed by emplacement are comparable with these kinds of nodules, it enables us thus to further infer their mantle origin.