Funding for this research was provided by:
National Natural Science Foundation of China (41602250)
National Science and Technology Major Project (2016ZX05037003)
Science Foundation of China University of Petroleum (2462014YJRC038)
China Geological Survey (DD20160293)
Article History
Received: 29 June 2017
Accepted: 26 April 2018
First Online: 16 May 2018
Compliance with Ethical Standards
:
: The authors declare no conflicts of interest or financial disclosures to report.