Table 3-3 Characteristics of karst water system zoning in northern China
Continued
I. Western margin of Ordos Basin (Zone Ⅰ)
The western margin of Ordos Basin covers a total area of 36,261km2 , from Table Mountain and Helan Mountain in the north over the Black Mountain in the central part of the country, the big and small Luo Mountains and Qinglong Mountain, and to the south through the Yunwu Mountain and the east side of Liupanshan Mountain to the southern Jingfushan Mountain area, which is about 600km long in the north and south, east and west. North-south length of about 600km, east-west width of 50-100km strip spread. The geotectonic structure is the spine of Qilu-Helan Shan zigzag tectonics, which consists of a series of north-south oriented folds and reverse faults. Geomorphologically, the area is characterized by "dorsal sloping into mountains" and "dorsal sloping into valleys", with carbonate rocks exposed in the dorsal sloping mountainous areas. There are 19 karst water systems in the area***, and under such tectonic conditions, the main system structure types are "strike type" and "fault block and other types" (Table 3-1; Figure 3-2).
Second, the west side of Lvliang Mountain (Ⅱ area)
This area is roughly from the watershed of Lvliang Mountain Range in the east to the Yellow River in the west, and the northern boundary is in Qingshuihe County of Inner Mongolia, and the southern boundary is in Xiangning County of Shanxi, with a total area of 27,533km2. The regional geotectonic in the Lvliang Mountain compound dorsal to the Ordos Oblique Basin Transition of the slope area, the distribution of the stratum from the east to the west from the old to the new is generally to The inclination angle of the strata from east to west is less than 10°, and the Yellow River, which is the benchmark for controlling surface water and groundwater discharge, flows from north to south from the west side, which makes this area form a highly consistent situation of stratigraphic tendency, surface water flow direction, and karst groundwater flow direction, and the karst springs are blocked by the Carboniferous Diapiric Coal System strata in the west side from overflowing to the surface, which forms the typical "monoclinal submissive type" karst water system (the "monoclinal submissive type"). This forms a typical "monoclinic and conformal" karst water system (Table 3-1; Figure 3-2). The whole area is divided into three karst water systems, namely Tianqiao Spring Area, Liulin Spring Area and Laimingsi Spring Area Karst Water System. The Leimingsi spring area is located on the east side of the peak ridge of the Luliang Mountain Range, and because its system pattern type is consistent with the other two systems, it is also classified into this area.
Three, the Fenwei Rift Valley area (Ⅲ area)
The Fenwei Rift Valley area includes a series of north-east sloping basins and basins and valleys on both sides of the stepped fracture tectonics *** with the composition of the Fenwei Rift Valley, the total length of more than 800km. The total length is more than 800km. There are 20 karst water systems distributed within and on both sides of the rift valley structure (Table 3-1; Figure 3-2). The rivers developed along the valley control the discharge benchmark of karst groundwater in each system, and the karst water is discharged in the form of large springs when it meets the side mountain fracture or other fracture obstruction in the process of seepage toward the discharge benchmark, and there are as many as 12 karst large springs with natural dry water flow rate of more than 1.0m3/s in the 20 systems. The karst groundwater system patterns are distributed except for the "inclined-basin type", and the main factor determining its type is the regional tectonic site where it is located. In the south of Linfen Basin, the system on the northwest side of the valley, as well as the system of the Horse Circle Springs in Xinding Basin are located in the southeastern edge of the Ordos Oblique Basin and Tranquility Oblique Basin, and are mainly "monoclinic inverted-type" systems; the karst water systems in the north of the Linfen Basin and the two sides of the Taiyuan Basin are respectively controlled by the compound dorsal slope of Lvliang Mountain and the dorsal slope of Huoshan Mountain and are mainly "monoclinic conformal-type" systems. The northern Linfen Basin and the two sides of the Taiyuan Basin are controlled by the Lvliang Mountain compound dorsal slope and the Huoshan Dorsal Slope respectively, which are mainly the "monocline conformal" systems; and the systems developed in the inner part of the basins are mostly the "fault block or other type" systems.
Four, Taihangshan-Yanshan bordering area (Ⅳ area)
This area is located in the northern section of the Taihangshan Mountain west of the border with the Yanshan Mountain area, with a total area of 29,057km2. geomorphology is the north-north-east direction of the Taihangshan Mountain Range and the Near East to the two directions of the Yanshan Mountain Range intersection of the transition area, coupled with the insertion of the Fenwei rift valley, a small fractured basins, the development of the oblique tectonics, and therefore, "oblique - basin type" karst, "oblique - basin type" karst. Therefore, the "oblique-basin type" karst water system is the biggest feature of this area. The five karst water systems in the whole region*** are of this type (Table 3-1; Figure 3-2). They are the Shuishentang-Qilihe spring area karst water system constituted by the Guangling-Weixian Basin, the Chengtouhui karst water system constituted by the Lingqiu Basin, the Laiyuan spring area karst water system constituted by the Laiyuan Basin, the Pingshang spring area karst water system constituted by the Baizhenjiao-Baijiazhuang Complex Oblique, and the Shuimachou spring area karst water system constituted by the Lingshan Complex Oblique.
Fifth, the western region of the Taihang Mountains (Area V)
This area includes the west side of the Taihang Mountains from the south of Shanxi Yangcheng - Jincheng, the north to Yu County, six karst water system (Table 3-1; Figure 3-2), a total area of 28295km2. geotectonics in the east wing of the Qinshui tilt, the stratigraphy of the overall tendency of the northern part of the north-northwest inclination, the eastern part of the east, south side of the north-north-east tilt. The North China Plain on the southeast side controls the overall flow of surface water and groundwater, forming a stratigraphic tendency and surface water, groundwater flow in the opposite direction of the pattern, these systems of karst groundwater in the direction of the North China Plain in the process of transportation in the region of the Lower Cambrian separator (or the Lower Ordovician relative separator) drainage, mostly for the separator plate blocking the water under the contact erosion of the falling springs. 6 systems are all attributed to the "monoclinal reverse-dip type". All six systems are categorized as "monoclinic inversion type" system model.
Sixth, the east of the Taihang Mountains (Area VI)
The east of the Taihang Mountains is located in the transition slope area from the Taihang Mountains to the North China Plain, with a total area of 15,887km2. The regional tectonics includes the east side of the fold belt of the Taihang Mountains and the Taihang Mountains pre-mountainous rupture (Dingxing-Shijiazhuang and Xingtai-Anyang-Xinxiang rupture). Controlled by the fold tectonics, the stratigraphy is generally tilted to the south and east of the North China Plain, and the situation is similar to that of the karst water system in the western district of Lvliang, where the stratigraphic tendency and surface water flow direction are consistent with that of the groundwater flow direction. The whole area*** is divided into 10 karst water systems (Table 3-1; Figure 3-2), and is dominated by the "monoclinic subduction type". Influenced by the fracture zone in front of the mountain, and the typical "monoclinic submissive" system structure is the difference between the system downstream of the karst water pressure zone is cut by the fracture zone, spring water due to the fault side of the waterproof top plate strata of the water blockage overflow and become.
Seven, west of Yu (Ⅶ area)
The karst water system of west of Yu is mainly distributed in the northeast of west of Yu, with a total area of 24871km2. 11 karst water systems are divided in the whole area*** (Table 3-1; Figure 3-2). The main body of the area develops east-west, north-west and north-east three groups of tectonic traces, these tectonic complexes accommodate each other and constrain each other in the process of their development and evolution, obviously controlling the development and distribution of geomorphology, groundwater and surface water basins in this area. The overall characteristic of the karst water system in this region is that the development scale is relatively small, with the area of 11 systems exceeding 1,000km2, and the average area of 539.19km2.
Eight, Yanshan-Liaoxi Region (Ⅷ)
Yanshan-Liaoxi Region actually includes the east side of the northern section of Taihang Mountain, Yanshan Region and Liaoqi Region, with a total area of 78,681km2. Liao Xi District, Yanshan District, and Liao Xi District, the total area is 86,681km2. Because the karst water in the northern part of Yanshan District and Liao Xi District is less studied, the karst water system has not been divided yet, so they are temporarily merged into Yanshan-Liao Xi District. The Yanshan movement has the most profound influence on the geological structure of this area, and the strong regional tectonic movement makes the carbonate strata produce in the form of steeper strips or fault blocks, which determines the smaller scale of the karst water system, and the average area of the 11 karst water systems in the whole area is 823.53km2; the structure is of the "monoclinal paraphyletic type", Structurally, they are "monoclinic subduction type", "strike type" and "oblique-basin type" (Table 3-1; Figure 3-2).
Nine, Luzhongnan District (IX District)
Luzhongnan District is mainly for the Luzhong middle and low hills, with a total area of 57,163km2. The north and west sides are the North China Plain, and the east side is the Yiyi and Blossom Fracture which constitutes the Tantu Fracture, and the south boundary is roughly in the Tancheng-Tai'erzhuang-Weishan area in the Shandong-Jiangsu border, which is 57162.6km2 in total area, with a total area of 57162.6km2. The total area is 57,162.6km2, and the stratigraphic structure of the karst water system in the area is controlled by the Luzhong dome tectonics, and the overall distribution of the karst water system from the central part of the area to the surrounding area from the old to the new is in the form of a ring belt and interspersed with a number of basins and valleys in the east-west direction or the north-west direction, and at the same time, under the control of the geomorphology of the terrain and the karst groundwater is also discharged to the surrounding areas and the basins and valleys. This kind of geotectonic and geomorphologic pattern determines that the structural pattern of karst water system in this region is mainly "monoclinic sublime type" and "syncline-basin type". According to statistics, among the 31 karst water systems in the region (Table 3-1; Figure 3-2), 21 and 6 systems of "monoclinic subduction type" and "oblique-basin type" respectively account for 87% of the total number of systems, and the remaining 3 types account for 4. Due to the cutting of the strata by the basin and valley controlling fractures developed in the dome tectonics and the small topographic elevation difference in the carbonate rock area, the driving force of the karst groundwater formed is also small, which is the reason for the relatively small scale of karst water system development in this area. The average area of karst water system in the region is only 949.19km2 compared with the Taihang Mountains and Luliang Mountains where carbonate rocks are exposed over a large area.
Ten, Xuhuai District (Area X)
Xuhuai District is neighboring with Luzhongnan District in the north and is bounded by the Tantanlu Fracture in the east, North China Plain in the west, and the east-west Suxian Fracture in the south with the total area of 11,046.8km2.
Tectonics of Xuhuai Arc Tectonics is the main factor. Tectonically, it is the Xuhuai Arc Tectonics. The Xuhuai area is a "fault block or other type" system model, and the Huaibei system, which is dominated by the Sanzha syncline, is classified as a "syncline-basin type" model (Table 3-1; Figure 3-2).
Eleven, Taizihe District (Ⅺ District)
The Taizihe District is the northeastern end of the Qianshan Mountain Range, the southern extension of the Changbai Mountain Range. A series of bead-like oblique tectonics are distributed along the Taizihe River to form the Taizihe Complex Oblique Tectonics. From west to east, including the Liaoyang oblique, Niuxintai oblique, Benxi oblique, Tianshifu oblique, etc., they *** with the combination of nearly east-west spread of the Taizihe depression belt, depression belt north and south for the ancient metamorphic system of taikuyu, yuan guyu, Paleozoic carbonates and coal strata are distributed in the depression belt and by the north-south, east-west faults cut into different scales of the fault block. The region is temporarily divided into two systems, the Liaoyang karst water system and the Benxi karst water system (Table 3-1; Figure 3-2). The Benxi karst water system contains several oblique tectonic basins, and at least four underground rivers and several karst springs are distributed within the system, which is limited to the extent of research and cannot be refined. Under the control of regional tectonic structure, the karst water systems in the region belong to the "oblique-basin type" structural pattern. Climate, geological structure and the influx of a large number of external sources of water make the karst in this area particularly developed, and there are several underground rivers in the area, which are rare in the north.
Twelve, Brigade District (D.E.D.)
The Brigade District is located at the intersection of the Fuzhou Plateau Depression of the Jiaoliao Plateau Rise and the Fuzhou-Dalian Depression, and it is the only sea-front district in the northern karst system subregion (Table 3-1; Fig. 3-2). Under natural conditions, the karst water in the area receives infiltration of precipitation and recharge from surface river seepage in the eastern metamorphic area, and seeps westward to the coast to be discharged in the form of submarine springs.
Thirteen, Huainan District (ⅩⅢ District)
This district is in the eastern part of the Qinling latitudinal tectonic belt, adjacent to the Hefei Depression in the south, Bengbu Rise in the north, and Tantulu Fracture in the east, with a total area of 3,118.2km2. Folds have been developed in the area, and south of Huaihe River there are the Damaoshan Slope and Bakongshan Dorsal Slope with the axial direction of folds being mostly north of 70 ° ~ 80 ° west and dipping to the east. There are four karst water systems in the whole area, and the system structure is categorized into three modes, namely, "strike-type", "monoclinic submissive-type" and "oblique-basin-type". The karst groundwater is recharged by precipitation infiltration through the carbonate rock exposed area and the covered area, and is mainly submerged into the plains in front of the mountains or the Huaihe River, except for a small amount of drainage in the form of springs.