TSR Action and Genesis Mechanism of Antimony Deposit: Evidence from Aromatic Hydrocarbon Geochemistry of Bitumen from Paleo-Oil Reservoir in Qinglong Ore Field, Southwestern Guizhou Depression, China

In Qinglong ore field, the paleo-oil reservoir is found to be associated with antimony deposits, and they have a close genetic relationship. this study, aromatics geochemistry of bitumen was studied further discuss thermochemical sulfate reduction (TSR) reaction mechanism mineralization. A total 124 aromatic compounds were identified by gas chromatography–mass spectrometry (GC–MS) analysis in samples, including abundant phenanthrene series, dibenzothiophene fluoranthene chrysene small number fluorene naphthalene dibenzofuran biphenyl triaromatic steroid series. Aromatic parameters such as trimethylnaphthalene index (TMNr), methylphenanthrene (MPI), distribution fraction (MPDF, F1, F2), methyldibenzothiophene parameter (MDR), C28TAS-20S/(20R + 20S), benzofluoranthene/benzo[e]pyrene indicate that over maturity level. The abundance amount benzofluoranthene, fluoranthene, pyrene, anthracene, retene, perylene, suggest organic matter source mainly low aquatic organisms, mixed higher plant. They detected certain compounds, ternary diagram DBF–DBT–F binary plot Pr/Ph–DBT/P, DBT/(F DBT)–DBF/(F DBF), Pr/Ph–DBT/DBF reveal rock formed marine environment weak oxidation reduction. comprehensive shows originated from Devonian rocks, just like other reservoirs natural Nanpanjiang basin. Abundant series detected, indicating underwent degree TSR reaction. We believe evolution oil field participated mineralization; is, hydrocarbon acted reducing agent transformed SO42− oilfield brine into H2S through TSR, providing reduced sulfur creating environmental conditions for