Geochemical characteristics of the Permian sedimentary rocks from Qiangtang Basin: Constraints for paleoenvironment and paleoclimate

  • Author(s): Junjie Hu, Qi Li, Chunyan Song, Shuangqing Wang, and Bin Shen
  • DOI: 10.3319/TAO.2016.08.08.01
  • Keywords: Geochemistry, Paleoenvironment, Paleoclimate, Permian, Qiangtang Basin
  • Paleoclimate was generally moist during the Early Permian of Jiaomuri area
  • Sediments were deposited mainly beneath a slightly oxic water column
  • Zhanjin Formation took place under fast sedimentary rate with low productivity
Abstract

Qiangtang Basin is expected to be an important strategic area of petroleum exploitation in China. However, barely research has been done on the Permian strata in this area. In this paper we present geochemical data of Lower Permian Zhanjin Formation from Jiaomuri area, aims of reconstructing the paleo-depositional environment and providing information for further petroleum exploration. The geochemical characteristics of 19 samples were investigated. In generally, the samples show a developed mud flat character and light richer clay content. The geological data were used to constrain the paleoredox environment, which proved that these sediments were deposited mainly beneath a slightly oxic water column with relative low paleoproductivity as evidenced by the P/Ti (mean of 0.07) and Ba/Al (mean of 20.5). The palaeoclimate indexes such as C-value (0.24–1.75) and Sr/Cu (1.28–11.58) reveal a humid climatic condition during Zhanjin Formation sediments deposited. In addition, theω(La)N/ω(Yb)N ratio values indicate a fast sedimentary rate during deposition period.

 

Read 669 times