New SIMS U-Pb age constraints on the largest lake transgression event in the Songliao Basin, NE China

PLoS One. 2018 Jun 26;13(6):e0199507. doi: 10.1371/journal.pone.0199507. eCollection 2018.

Abstract

The largest lake transgression event (LTE) associated with lake anoxic events (LAE) and periodic seawater incursion events (SWIE) in the Songliao Basin, northeastern China, occurred during deposition of the Cretaceous Nenjiang Formation. The Yaojia-Nenjiang Formation boundary (YNB) marks the beginning of the LTE, as well as LAE and SWIE. However, there is an absence of direct radioisotopic dating, and therefore the age of the YNB, as well as the beginning of LTE, together with their relationship with other geological events, is strongly debated. Here we present a new SIMS U-Pb zircon age from the lowermost Nenjiang Formation. The bentonite bed located 9.88 m above the YNB of the X1-4 borehole was analyzed. Twenty-five analyses of 25 zircons were conducted, which produced a weighted mean age of 85.5±0.6 Ma (MSWD = 0.87). Based on the average sediment accumulation rate, the age of the YNB is suggested to be 85.7 Ma, indicating that the LTE began in the Early Santonian. The new ages provide a precise chronostratigraphic framework for climatic and geological events. Our new results imply that the beginning of the LTE, LAE and SWIE occurred almost simultaneously with short-term sea level rise, and probably had a close relationship with OAE3.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • China
  • Geography
  • Lakes / chemistry*
  • Lead / analysis*
  • Luminescence
  • Spectrometry, Mass, Secondary Ion / methods*
  • Time Factors
  • Uranium / analysis*

Substances

  • Lead
  • Uranium

Grants and funding

D.X. acknowledges support from the National Natural Science Foundation of China (Grant Nos. 41790452 and 41302008; http://www.nsfc.gov.cn/publish/portal1/), the National Basic Research Program of China (Grant No. 2012CB822002; http://www.most.gov.cn/eng/programmes1/200610/t20061009_36223.htm), and State Key Laboratory of Biogeology and Environmental Geology (Grant No. GBL21314; http://en.cug.edu.cn/Key_Laboratories/Key_Laboratories___Research_Centers.htm). J.H. acknowledges support from the National Natural Science Foundation of China (Grant No. 41372110; http://www.nsfc.gov.cn/publish/portal1/). H.H. acknowledges support from the National Natural Science Foundation of China (Grant Nos. 41425013 and 41688103; http://www.nsfc.gov.cn/publish/portal1/), and the Strategic Priority Research Program of the Chinese Academy of Sciences (http://english.cas.cn/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.