粵北中生代含煤地层,最早于1929年发现在湘粵交界之艮口村。李毓尧、朱森等于1934年将其命名为“艮口系”。后虽历经多次研究,亦取得许多宝贵的实际材料,但终因其沉积厚度大,岩性、岩相、构造比较复杂,再加上研究程度的限制,故多年来对其层序及划分、对比,尚未能得到一个比较完整的概念。 The northern Guangdong Mesozoic coal-bearing strata, first discovered in 1929 in the junction of Hunan and Guangdong Gen Kou Village. Li Yuyao, Zhu Sen equal to 1934 named “Gen mouth system.” After many studies, many valuable practical materials have been obtained. However, due to its large sedimentary thickness, lithology, lithofacies and tectonics, coupled with the limitation of research level, its sequence and classification , Contrast, have not been able to get a more complete concept.