| PDF: | |
| Time: | 2007 |
| Journal: | Journal of Jilin University (Earth Science Edition) |
| Volumn: | 37 |
| Issue: | 6 |
| Pages: | 1217-1223 |
| Type: | Other |
| Author: | Hu Wang,Changqing Zheng,Pujun Wang,Yulong Huang |
Abstract: | The 3rd member of Yingcheng Formation was detailed studied by large scale mapping of lithology and lithofacies, 2D surveying of small lithology and lithofacies section and identifying rocks. The 3rd member of Yingcheng Formation contains 2 cycles which changed from intermediate-basic rocks to intermediate acidic rocks Cycle ① changed upward from quartz-andesite, andesite, andesitic agglomeratic lava, andesitic agglomerate, andesitic breccia and andesitic breccia tuff, to sandy tuff, to sandy tuff lava. Cycle ② changed front basaltic andesite. basaltie agglomeratic lava to dacite. dacitic tuff lava. dacitic tuff. The upward vertical lithofacies succession of cycle ①is: lower subfacies of effusive facies, diatreme subfacies of volcanic conduit facies, airfall subfacies of explosive facies reworked volcanogenic sediments sub-facies of volcanogenir sedimentary facies pyroclastic flow subfacies of expiosive face. The upward vertical lithofacies succession for cycle②is: lower arid tipper subfacies of effusive facies, diatreme subfacies of volcanic conduit fades, lower subfacies of effusive fades, inner sufades of intrusive fades, lower subfades of effusive facies, pyroclastic flow subfades of explosive fades, reworked volcanogenic sediment subfades of volcanogenic sediment facies, lower subfacies of effusive fades. The lava in 3rd part of Yingcheng Formation erupted in the late period of fault subsidence and it is the important lithology record of the Songliao Basin\'s transform from a fault subsidence basin to a sag basin. |