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华北陆台北缘近千公里的麻粒岩带不是同为太古宙的一个带，其西的晋蒙高级地体以含有孔兹岩系而有别于其东的冀东地体。若以中下地壳出露的孔兹岩系划界，其东、西两块地体的界限大致在赤城－阜平一线。本文只讨论了孔兹岩系时代问题。根据孔兹岩系①富含大理岩（太古缺大理岩）；②所含石墨为生物成因；③地球化学特征与显生宙的而不与太古宙的沉积岩相似；④与下伏太古宙麻粒岩套为两大构造层；⑤与冀东太古宙麻粒岩的ＰＴ轨迹不同；⑥仅有早元古代的同位素年龄；⑦区域地质构造讨论；⑧中元古代的不变质辉绿岩墙群所限定；⑨晋蒙地体不变质盖层为寒武、奥陶系，而不同于冀东地体为中元古的长城、蓟县系等，结论认为不但孔兹岩系的变质期为早元古代，而且原岩时代也为早元古代。
Nearly a thousand kilometers of granulite belt in the northern margin of North China and Taiwan is not a belt of the Archean. The high-grade Jin-Meng terrane in the west is distinguished from the eastern Jidong terrain by the Khondalite series. If the khondalites exposed in the middle and lower crust are demarcated, the boundaries of the two east and west terrains roughly line Akagi- Fuping. This article only discusses the Khodz rock series era. According to the khondalite series, ① rich in marble (Archean missing marble); ② contains graphite as a biogenic cause; ③ geochemical characteristics and Phanerozoic not with the Archean sedimentary rocks similar; ④ and the underlying Archean hemp The granulite sets are composed of two major tectonic layers; (5) the PT trajectories are different from the Jidong Archean granulites; (6) there are only the Early Proterozoic isotopic age; (7) regional geological tectonics; (8) the Proterozoic metamorphic diabase wall Group. ⑨ The metamorphic caprock of the Jin-Meng terrane is Cambrian and Ordovician, but different from the Great Wall and Jixian system of Middle Proterozoic in the Jidong terrain. It is concluded that not only the metamorphism period of the Khondalite series is Early Proterozoic, but also the original rock age as early Proterozoic.