• 中文核心期刊要目总览
  • 中国科技核心期刊
  • 中国科学引文数据库(CSCD)
  • 中国科技论文与引文数据库(CSTPCD)
  • 中国学术期刊文摘数据库(CSAD)
  • 中国学术期刊(网络版)(CNKI)
  • 中文科技期刊数据库
  • 万方数据知识服务平台
  • 中国超星期刊域出版平台
  • 国家科技学术期刊开放平台
  • 荷兰文摘与引文数据库(SCOPUS)
  • 日本科学技术振兴机构数据库(JST)

Density structure of the crust in the Emeishan large igneous province revealed by the Lijiang- Guiyang gravity profile

  • Abstract: The Emeishan large igneous province (hereafter named by its acronym ELIP) is the first accepted large igneous region in China. The current study tries to reconstruct the density structure of the crust in this region. For this purpose, we conducted the gravity survey along an 800-km-long profile, which stretched laterally along the latitude 27°N from Lijiang (Yunnan province) to Guiyang (Guizhou province). The fieldwork included 338 gravity measurements distributed from the inner zone to the outer zone of the mantle plume head. After a series of gravity reductions, we calculated the Bouguer gravity anomaly and then constructed the density model for ELIP by iterative forward modeling from an initial density model tightly constrained by wide-angle seismic reflection data. The topography of the Moho, here physically interpreted as a density discontinuity of ~0.4 g·cm–3, gradually rises from the inner zone (~50 km deep) to the outer zone (~40 km), describes a thicker crust in the inner zone than in any other segment of the profile and largely reproduces the shape of the Bouguer gravity anomaly curve. Both the Bouguer gravity and the density structure show significant differences with respect to the inner zone and the other two zones of ELIP according to the commonly accepted partition of the Emeishan area. A thicker and denser middle-lower crust seems to be the main feature of the western section of the profile, which is likely related to its mafic magmatic composition due to magmatic underplating of the Permian mantle plume.

     

/

返回文章
返回