Abstract:

The recognition of marine source rock validity is important to Lower Palaeozoic exploration in Ordos Basin. Carbonatite of lower Ordovician series is not the real source rock because of its congenital quality including low TOC, poor kerogen type, and little hydrocarbon generation potency. On the contrary, the platform slope facies that formed middle Ordovician Pingliang series is a set of fine marine source rock. Pingliang series source rock includes 80 to 200 meters mud shale and marlstone, which distributed in a large area around western and southern margin of Ordos Basin. With typeⅠkerogen and high organic content（>0.2%）, Pingliang source rock mainly belongs to above average rank, which attained high to post mature level and must have had a relatively high extent of hydrocarbon generation and expulsion history. Pyrolysis simulating experiment suggested that there have been 0.432 billion tons of hydrocarbon resource produced by Pingliang source rock in history. A perfect prospect should be expected.

Key words:  Ordos Basin, marine source rock, carbonatite, Pingliang series, exploration prospect