The strata in Sanqingshan area are exposed to varying degrees from Proterozoic to Quaternary. Including Mesoproterozoic Zhang Cun Group, Shang He Town Group, Nanhua System, Sinian System, Palaeozoic System and Mesozoic System.

The Mesoproterozoic Zhang Cun Group, distributed in the northern part of Sanqingshan Mountain, is an ocean basin island arc ophiolite melange. The rock assemblage consists of shallow metamorphic spilite, quartz hornblende, volcanic tuffaceous-muddy turbidite deposits, mixed with a large number of ophiolite blocks. Neoproterozoic is mainly located in the northern part of Sanqingshan Mountain, with Shang He Town Group in the lower part, which is mainly composed of shallow metamorphic sandstone and slate sandwiched with rift-type bimodal volcanic rocks (basalt and rhyolite), and is not integrated on Zhang Cun Group; The middle part is South China marine clastic rock, moraine mudstone conglomerate and limestone; The upper part is Sinian siliceous rocks and carbonate rocks.

Paleozoic is mainly distributed in Sanqingshan and its surrounding areas. The CAMBRIAN is mainly composed of carbonate intercalated mud and siliceous shale, with black shale at the bottom. The Ordovician is dominated by shale, with nodular limestone and rich graptolite fossils; Silurian is argillaceous clastic rock; Devonian is composed of glutenite, sandstone and silty shale, which are usually unconformity on the pre-Devonian. Carboniferous and Permian are carbonate rocks. The Mesozoic is dominated by Jurassic and Cretaceous.

Triassic is locally distributed, with carbonate rocks and shale in the middle and lower part and coal-bearing clastic rocks in the upper part, which are often unconformity in the early strata; Jurassic is exposed at the edge of Mesozoic basin outside Sanqingshan, with light sandstone in the lower part, variegated sand shale and silicified wood fossils in the middle part and continental volcanic complex in the upper part. The Cretaceous Mesozoic continental basin distributed outside Sanqingshan Mountain is dominated by red and variegated clastic rocks, with continental pyroclastic rocks in the lower part and dinosaur eggs and dinosaur bones in the upper part.

The Cenozoic only developed in Quaternary with limited distribution, mainly distributed in valleys, depressions and plains, with alluvial clay, loam, gravel layer or gravelly clay layer as the main materials. Distributed in the northwest and northeast of Sanqing Mountain, it is a northeast Jura-style fold composed of South China-Silurian sedimentary cover. Regionally, the present folds are often covered by stratigraphic unconformity since Jurassic, so it is inferred that they should be Indosinian folds. Mainly includes:

(1) Huangtuling Complex Anticline: Located in Huangtuling area in the northwest of Sanqingshan Mountain, it is a part of Huangtuling-Hua Kai Complex Anticline in this area, with its axis northeast, folds northeast and south-west spreading, with an area of about 15km. The axial plane is almost vertical, and the posture of the two wings is disordered. The northwest wing is steep, 300 ~ 350 ∠ 30 ~ 75, and the southeast wing is slow, 120 ~ 150 ∠ 30 ~ 60. The core stratum is Nanhua stratum, and the wing stratum is composed of Sinian-Ordovician stratum. The south wing is widely exposed, and some secondary anticline structures are often formed.

(2) Huamei Mountain Syncline: It is distributed in the northeast of Sanqingshan Mountain, with the axis running northeast-southwest, with the southwest end on the side of Huaiyushan rock mass, and the northeast end extending to this area through the seismic source, with the axis running 67, the northwest wing slightly steep with an inclination of 40-60, and the southeast wing relatively gentle with an inclination of 30-50. The core stratum is the early Ordovician Yinzhubu Formation, and the wing stratum is composed of the late Cambrian stratum. The fault structure in this area is well developed, and the fault direction is mainly NE, followed by NE and NW. From the time of formation, the NE-trending fault is the earliest, followed by the NE-trending fault zone, and the NW-trending fault zone is the latest. The main fault structures are normal faults and reverse faults. The main faults are LAM Raymond-Zihuzhen fault zone, Xiaokeng-Bajiaowu fault zone and Bajiaowu-Xiaxikeng fault zone, all of which are normal faults, forming a fault valley, and cutting the main body of Sanqingshan into a "triangular fault block mountain".

(1) LAM Raymond-Zihuzhen Granite Fault: Located in the southeast of Sanqingshan Mountain, it is composed of many faults extending 50 ~ 60 to the northeast, with an inclination of 60 to the southeast. The northwest plate rises and the southeast plate falls. There are cleavage zone, schistosity zone and fault breccia zone along the fault formed by early shear activity, with a width of 10~40m, which are multi-stage active faults and a river valley system along the fault. Such as linear gullies and knee-shaped water systems.

(2) Egongling-Xiaxikeng granite fault: located in the east of Sanqing Mountain, it strikes northwest and leans northeast with an inclination of 65 ~ 70, with the southwest plate rising and the northeast plate falling. Foliated granite and structural breccia are developed on the fault plane, and the silicification of rocks and recrystallization of minerals are strong. See timely crystal clusters and agates. A fault valley landform is formed along the fault, and cliffs formed by silicified belts can be seen intermittently in the southeast of the fault.

(3) Xiaokeng-Bajiaowu granite fault: located in the northwest of Sanqing Mountain, it strikes NNE and tends to NW with an inclination of 70, cutting off the NE fault, and the southeast plate rises and the northwest plate falls. Structural breccia, silicified rock and cataclastic rock are developed along the fault. Along the strike of the main fault, a fault valley landform is formed. Magmatic rocks in Sanqingshan area are frequent and widely distributed, and their magmatic rocks are mainly super-acidic intrusive rocks, that is, Sanqingshan granite body (a part of Huaiyushan rock body) formed in the late Yanshan period, which constitutes the main body of Sanqingshan. Sanqingshan granite body is located in the middle of Sanqingshan Mountain, with irregular plane shape and exposed area of about 98km2. Granite intrudes into the Nanhua-Ordovician strata in the south wing of Huangtuling compound anticline, and is produced in the form of bedrock and rock plant. The intrusive contact boundary is irregular, wavy, harbor-shaped or branched, and the contact surface tends to the surrounding rock. In the inner contact zone, a dense and hard fine-grained condensation edge with a width of 1~3cm is seen, and the residual roof in the rock mass is general and the erosion degree is shallow. The outer contact zone has strong thermal contact metamorphism, forming a thermal contact metamorphic halo with a width of 500~2000 meters. The mainstream structure in the rock mass is not developed, but the inherited dikes are developed, mainly including granite fine-grained rocks, pegmatite, granite porphyry, diorite porphyry and gabbro diabase dikes. Diorite inclusions in rocks are relatively rich, and there are many dark minerals with different sizes and irregular shapes. Wall rock alteration mainly includes skarnization, silicification and chloritization. The main mineral components of rock mass are potash feldspar, plagioclase, quartz and biotite.

In Sanqingshan granite, there are many diorite inclusions with different sizes and irregular shapes, which are relatively rich in dark minerals. Granite complex is obviously controlled by NE-trending fault structure, but the intrusive contact boundary of rock mass is irregular, the residual roof in rock mass is developed, the exposed width of external contact thermal metamorphic belt is large, the primary flow structure is not obvious, and the average oxidation coefficient of rock is 0.47. During the main intrusion period, the rock mass in the granite foundation is divided into three facies zones, the marginal phase is fine-grained porphyritic potash granite, the transitional phase is medium-grained to medium-coarse porphyritic potash granite, and the central phase is coarse-grained porphyritic potash granite only found in the valley, with more residual roof in the surrounding rock, indicating that the degree of rock mass erosion is shallow. The emplacement depth of granite is estimated to be 4000 ~ 4500 meters. The main intrusions of the lithofacies Sanqingshan granite can be divided into three facies zones, namely:

Marginal facies: the lithology is fine-grained (fine-porphyritic) porphyritic biotite adamellite;

Transition phase: medium-fine grained porphyritic biotite-feldspar granite;

Internal phase: medium-coarse grained porphyritic biotite potassium feldspar granite.

The three facies belts do not form concentric rings on the plane, especially the internal facies distribution is irregular, which is caused by the great change of tectonic stress field in this area during the magma upwelling, the turbulent environment of magma condensation and crystallization, and the uneven degree of topographic cutting and denudation after the crust rises. The internal structure of granite body is in Sanqingshan granite body, which mainly has two groups of vertical joints, one is NE-NNE and the other is NW, forming a checkerboard combination. These joint and fissure structures are characterized by tensile shear, low density, high strength, long extension, deep cutting and banded output, which are the main transformation of granite landscape in Sanqingshan. In addition, a group of nearly horizontal joints are developed in the area, and their fracture network has changed from * * *, and various unique landscapes have been formed through erosion, scouring and weathering. Structural traces of joints can be seen in most hilltop forest landscapes. From southwest to northeast, the former tends to converge and spread, forming a broom-like output in macro, with a large scale of development, and often spreading in a strip shape in space, which is the main structure controlling the Xifeng wall (heavy wall in the West Sea, Jiutian Great Wall, etc.). ) and the Southern Canyon (Fushoumen, Yixiantian, etc. ). The latter generally moves to the northwest, turning slightly from south to east to north and south. Its scale gradually increases from north to south, showing a strip shape, which is the main structure controlling the central peak column, the southeast peak wall and some canyons. In addition, a group of nearly horizontal joints are developed in granite, which is the main control structure of modeling stone landscape, that is, the landscape such as peak wall and peak column is cut and weathered by horizontal joints, forming various unique landscapes.