| PDF: | |
| Time: | 2012 |
| Journal: | Acta Petrolei Sinica |
| Volumn: | 33 |
| Issue: | 4 |
| Pages: | 541-550 |
| Type: | EI |
| Author: | Huafeng Tang,Bing Bai,Weihua Bian,Liyuan Wang,Haibo Sun |
Abstract: | The volcanostratigraphy of Yingcheng Formation was built up by volcanic edifices which migrated in lateral direction and overlapped in vertical succession. In present, internal structures of volcanic edifices are not clear. So development process of volcanic gas pools in Songliao Basin was decelerated. The models of strata texture within volcanic edifices were created by integrated analysis of acid lava, acid compound, and acid pyroclastic volcanic edifices as well as intermediate-basic lava ones. The strata texture of mostly acid volcanic edifices is pseudostratified texture. The intermediate-basic lava volcanic edifices has stratified texture besides the pseudostratified texture. The dip angle of acid volcanic edifices (with the pseudostratified texture) is bigger than that of the intermediate-basic volcanic edifices (with the stratified texture). The dip angles show normal distribution, skewed normal distribution or bimodal shape. The primary stratified occurrence of volcanic rocks is controlled by types of volcanic edifices, eruptive paleogeomorphology (such as contemporaneous fault and paleoslope), and reformed by later compressional and tilting activities. Purly later low relief normal faults or reverse faults and impact the occurrence slithtly. This study offers a theoretical basis for meticulous depiction of internal structure of volcanostratigraphy. |