It is determined by transmited light microscopy that the abundant amorphous organic matter (AOM) is contained in the lacustrine dark mudstones of the Palaeogene Wengchang and Enping Formations.

• 普通透射光镜观察结果表明,珠三坳陷早第三纪文昌组和恩平组的湖相暗色泥岩中都含有丰富的无定形有机质。