The establishment of Lishui movement led to the changes of Cretaceous stratigraphic system in Zhejiang Province. It is considered that the Shang Tang Formation, which is dominated by volcanic rocks, and the strata above it are "another structural sublayer" superimposed on the Yongkang Group, and a new stratigraphic system is established, which is called Tiantai Group. The lithology and lithofacies above Shang Tang Formation are similar to Chaochuan Formation and Yan Fang Formation, and the strata are renamed Laijia Formation respectively. In recent years, it was renamed as "Liangtoutang Formation" and "Chichengshan Formation". This great change has been accepted by many geologists in Zhejiang Province, becoming the mainstream view and being quoted by the outside world. However, some geologists represented by Yu, after studying the geological phenomena reported in Lishui basin, combined with some regional geological data, think that the Formation is integrated on the typical Guantou Formation, and hold negative opinions on Lishui movement.
In fact, as early as 1989, Ding Baoliang and others thought that "the Shang Tang Formation should be roughly equivalent to the Chaochuan Formation, with heterogeneous deposition in the same period", or "Volcanic Chaochuan Formation". By extension, "Tiantai Group" is just Yongkang Group with many volcanic interlayers. If so, the "neotectonic sublayer" and the "Lishui Movement" will become castles in the air.
Ma Wuping (1992) put forward the comparison scheme of the three major groups in Zhejiang as shown in Table 4-2. He superimposed Tiantai Group on Yongkang Group to form a "neotectonic sublayer" equivalent to Qujiang Group.
Table 4-2 Comparison Table of Cretaceous Strata Division in Zhejiang Province (Excerpt)
Focusing on the relationship between Tiantai Group, Yongkang Group and Lishui Movement, this paper made a field investigation in Lishui Basin, a famous place of Lishui Movement, from Tongling Village in the southwest of Lishui City to Yucun along the highway, and then pursued Fangyan Formation along the ravine to the east until Nandamenlou Village in Shan Zhi in the south of Ming Dynasty. Due to the gentle occurrence of strata, the so-called "Fangyan Formation" conglomerate has a large exposed area along the Tongling-Yucun highway, but after entering the ravine to the east, it is only exposed in a strip shape on the south slope of the south mountain of Jiangjunmiao, and there are two thin layers of conglomerate under it, both of which are sandwiched in dark brown shallow lake subfacies siltstone. The siltstone is about 100 m above the conglomerate layer, and the "Shang Tang Formation" is deeper. These siltstones belong to Chaochuan Formation in lithology, lithofacies and sequence. Volcanic rocks of Shang Tang Formation constitute the backbone of this mountain. From the bottom of the ditch, the occurrence of "Shang Tang Formation" and "Fangyan Formation" is quite coordinated, and there is no phenomenon that "the horizons of Shang Tang Formation overlap with Chaochuan Formation and Fangyan Formation, extending in the NNE direction and obviously unconformity". The author completely agrees with (1996, 1997) that "this conglomerate is only underwater fan deposit". The thickness of lacustrine gravity flow in this layer is only 20-30m and 60-70m, which is far less than that of the real Yan Fang Formation. Because the Yan Fang Formation is a molasse-like stratum formed in the stage of rapid crustal uplift, it should be transformed into lake facies from bottom to top by braided river subfacies. This braided river subfacies composed of glutenite, sandstone and siltstone can be seen in the upper and lower members of any Yanfang Formation, and the so-called "Yan Fang Formation" in Lishui Basin is a typical shallow lake subfacies siltstone. The author thinks that it is a high-density current deposit formed by flood in lake environment, which is completely different from the formation mechanism, scale, phase sequence and sedimentary position of the Molasite Formation in Yan Fang Formation. Therefore, there is no real Yan Fang Group, and the "angle unconformity" relationship between "Shang Tang Group" and "Yan Fang Group" is out of the question.
Similar to Lishui Basin, Yan Fang Formation composed of gravity flow conglomerate can also be seen in Jingling section of Xinchang Basin. There are three eruptive-sedimentary cycles above the red formation of lakeside subfacies, all the time under the breccia tuff, with tens of meters of conglomerate. According to the regional survey data, this volcanic-sedimentary rock is divided into the first member of Chaochuan Formation, and the overlying "Keshan rhyolite" is divided into the second member of Chaochuan Formation. In later geological work, the first member of Chaochuan Formation was considered as Yan Fang Formation, and Keshan rhyolite layer was located above Yan Fang Formation. For the Jingling section of Xinchang, the author thinks that the conglomerate tens of meters below the first layer of breccia tuff is deposited by lake gravity flow, and the siltstone of the lakeside subfacies of the underlying Chaochuan Formation has obvious bottom scouring surface (Sheet I-3; Figure 4-5). The conglomerate has a typical progressive composite superimposed upward thickening sequence. The higher level of this profile has not been investigated, and it seems that it may be the superposition of gravity flow caused by multiple eruptions, which belongs to event superimposed deposition and is not the real Yan Fang Formation. The first set of conglomerate investigated by the author is directly transformed from lakeside facies to conglomerate without transitional fluvial facies. This phase sequence is different from that of Yanfang Formation, and undoubtedly belongs to gravity flow subfacies. According to the regional survey data of Zhuji Sheet, some brachiopods and plant fossils of Chaochuan period were collected in the conglomerate interlayer under Keshan rhyolite. Accordingly, these conglomerates should be deposited by lake gravity flow sandwiched in Chaochuan Formation.