Abstract: Most of the oil and gas of China originated from the terristrial source rock while with poor constrain on the genesis of these rocks. Recent research on the marine counterpart, however, has shown that the burial of reactive iron is vital for the accumulation of organic carbon. This paper reviewed the iron cycle and its biogeochemical effects in the lake, and suggested that the reactive iron burial in the lake sediments should be affected by the sulfate reduction just like in the marine realm. The enhanced sulfate reduction will cause the large scale release of the nutrients, i.e., mainly the phosphate that will in turn stimulate the eutrophication of the lake favorable for the production and burial of organic carbon. Marine incursion events occurred during the evolution of the Songliao Basin
which would have contributed for the formation of the high quality source rock in the Songliao Basin.