Paleozoic oil-source rock correlations in the Tarim basin, NW China

We studied a suite of 40 oils and extracts of purported source rocks from t he Tarim basin in NW China. The main group of oils comes from Tazhong and T abei wells, which sample the largest known petroleum accumulations in the b asin. These oils can be statistically correlated with extracts of Ordovicia n rocks based upon high relative concentrations of 24-isopropylcholestanes and low relative concentrations of dinosteranes, triaromatic dinosteroids, and 24-norcholestanes. In contrast, extracts from Cambrian rocks have low r elative concentrations of 24-isoplopylcholestanes with high relative concen trations of dinosteranes, triaromatic dinosteroids, and 24-norcholestanes. Although some Tarim basin Cambrian rocks yield high total organic carbon co ntents, we see little evidence in the analyzed oil samples to suggest that they came from Cambrian source rocks. (C) 2000 Elsevier Science Ltd. All ri ghts reserved.