ORIGINAL PAPER The origin of high hydrocarbon groundwater in shallow Triassic aquifer in Northwest Guizhou, China Shan Liu . Shihua Qi . Zhaohui Luo . Fangzhi Liu . Yang Ding . Huanfang Huang . Zhihua Chen . Shenggao Cheng Received: 12 September 2016 / Accepted: 14 February 2017 Ó Springer Science+Business Media Dordrecht 2017 Abstract Original high hydrocarbon groundwater represents a kind of groundwater in which hydrocar- bon concentration exceeds 0.05 mg/L. The original high hydrocarbon will significantly reduce the envi- ronment capacity of hydrocarbon and lead environ- mental problems. For the past 5 years, we have carried out for a long-term monitoring of groundwater in shallow Triassic aquifer in Northwest Guizhou, China. We found the concentration of petroleum hydrocarbon was always above 0.05 mg/L. The low-level anthro- pogenic contamination cannot produce high hydro- carbon groundwater in the area. By using hydrocarbon potential, geochemistry and biomarker characteristic in rocks and shallow groundwater, we carried out a comprehensive study in Dalongjing (DLJ) groundwa- ter system to determine the hydrocarbon source. We found a simplex hydrogeology setting, high-level water–rock–hydrocarbon interaction and obviously original hydrocarbon groundwater in DLJ system. The concentration of petroleum hydrocarbon in shallow aquifer was found to increase with the strong water– rock interaction. Higher hydrocarbon potential was found in the upper of Guanling formation (T 2 g 3 ) and upper of Yongningzhen formation (T 1 yn 4 ). Heavily saturated carbon was observed from shallow ground- water, which presented similar distribution to those from rocks, especially from the deeper groundwater. These results indicated that the high concentrations of original hydrocarbon in groundwater could be due to the hydrocarbon release from corrosion and extraction out of strata over time. Keywords Original high hydrocarbon groundwater Á Water–rock–hydrocarbon interaction Á Biomarkers Á Shallow Triassic aquifer Introduction Groundwater is the determining factor for oil–gas reservoir forming process. It controls the diagenetic environment, hydrocarbons migration and dissolution (Li et al. 2014; Feng and Han 2002). Water–rock– hydrocarbon interaction is the key factor for oil–gas reservoir spatial evolution and functions in the whole diagenetic process (Cai et al. 1997). Moreover, the interaction between water, rock and hydrocarbon is a complicated physiochemical process in which all the Electronic supplementary material The online version of this article (doi:10.1007/s10653-017-9923-8) contains supple- mentary material, which is available to authorized users. S. Liu Á S. Qi (&) Á Z. Luo Á F. Liu Á Y. Ding Á H. Huang Á Z. Chen Á S. Cheng Sate Key Laboratory of Biogeology and Environmental Geology, Wuhan 430074, China e-mail: shihuaqi@cug.edu.cn S. Liu Á S. Qi Á Z. Luo Á F. Liu Á Y. Ding Á H. Huang Á Z. Chen Á S. Cheng School of Environmental Studies, China University of Geosciences, Wuhan 430074, China 123 Environ Geochem Health DOI 10.1007/s10653-017-9923-8