| Karst cave as the important kind of karst landform has a special position ingeomorphology, speleology, karstology, hydrogeology. The Taihang Mountain is the region ofNorth China where carbonate cave is more developed. Mulan cave and Caoxian cave as thetypical caves of Mancheng County are located in the low mountainous area of the northernTaihang Mountain. For the Karst caves of Taihang Mountain area, previous studies are mostlyconcentrated in the Baiyun cave, Tiangui Mountain caves and Sardonyx cave, etc. Theresearch with Mulan cave and Caoxian cave is lacking, especially in cave morphology,structure, landscape types, formation environment and so on. This thesis carry on research tocave morphology, structure, chemical deposition landscape and formation environment ofMulan cave and Caoxian cave, The aim of this study is to reveal the unique nature of thecauses and the differences of formed environment and controlled factors. In order to providebasic data for cave system in northern China and a comprehensive study. And provide thescience reference for the development of cave resources, utilization and protection.This thesis explored Mulan cave and Caoxian cave typical characteristics and theirinfluence factors, reshaped their formation and evolution, proposed protection advice for caveresource protection, on the basis of field investigations on geologic landforms, fieldobservations on caves and the analysis on various data. Research conclusions are as follows:1.Mulan cave and Caoxian cave developed mostly in the dolomite of wumishanformation, Jixian system. Interformational fault and a kind of faults tectonic, such as runningNE, NW and NEE, control Caverns morphology, structure, distribution. Faults control cavedeposits morphological characteristics and geomorphological processes as infiltration channelbetween atmospheric precipitation and surface water and contact channel between caveenvironment and surface environment.2.Mulan cave extend tortuously in the plane, which looks like dragons that have wings.The cave is180metres long and62metres width. The distribution area is about11160m2.Mulan cave showed Hall-like caves and corridors. Caoxian cave is251metres long and123.5metres width. The distribution area is about31000m2. Caoxian cave showed Hall-like caves.3.It caused different landscape types of Mulan cave and Caoxian cave that amount of water is different in early developing stage and environment differ in wet and dry isdistinct.Mulan cave gravity water sediment are type complex, varied shapes, both drippingdeposition formed stalactites, geese tube, stalagmites and stone pillars, and also flowed waterdeposited flowstone, most of which are still developing. Caoxian cave are lesser chemicalsediments,only a small amount of pillars, but the erosion-corrosion landscape are richer,including orientational flute type, pocket type, tubing type.4.Caves are mainly under the control of several groups steep faults and bedding planefault.Bedding plane faults are developed in Mulan cave. Which not only influenced cavemorphology, structure, landscape types but also influenced cave-in collapse. Along withTaihang Mountains crustal movement, caves happened repeatedly collapse.In Mulan cave,early cave collapse deposit are size mixed, which block is smaller and calcareous，sandy witha compact cementation. Late cave collapse deposit block is large. Mechanical sediment inCaoxian cave are mainly cave collapse deposit. Early cave collapse deposit are compactcementation，Late cave collapse deposit are elevated structures.5.Tubular sinkholes and Linear sinkholes are developed in Mulan cave, Tubularsinkholes in Mulan cave is under the control of interformational fault. Linear sinkholes isunder the control of vertical fault. Water from sinkholes run into underground river finally.Underground river flows from south to north. Large sinkholes at Caoxian care mouth is one ofthe main source of cave flow in early development period. The sinkhole to the lower cave iscatchment area of two rivers,which was filled by running water clastic particle.The waterfrom sinkholes is important for the development of karst caves.6.Mulan cave and Caoxian cave are located south slope and north slope of Daniu-Tianpan mountain.They belong to different hydrologic systems. The formation anddevelopment of caves date from mid-late early Pleistocene. Mulan karst cave distribution atan altitude of242～260m range.which correspond to the fourth river terrace of Jie river.Caoxian karst cave distribution at an altitude of290～300m range. which correspond to thefourth river terrace of Cao river. Karst caves subjected to a number of intense tectonic activityafter their formation and caves collapsed seriously. Nowadays, Mulan cave roof rockthickness is about40m, relatively thin. Top of the cave rock fault is development.And the topof the hill is a depression.Vegetation is lush. which led to Mulan cave environment is more moist and chemical deposit landscape is rich. Nowadays, Caoxian cave roof rock thickness isabout50m. Cave lies to sunny side of the mountain. The vegetation is sparse. Exposedbedrock in most places that against the conserving water. which led to Caoxian caveenvironment is more moist dry.7.Mulan cave CO2concentration is relatively low compared with neighboring caves.Where faults are well developed, air exchange is frequent. And observation of Mulan caveCO2concentration is in the low season for tourism. During tourist season,a large number oftourists enter into cave,which will result in CO2concentration increase, air temperature rises,the humidity decreases. And undermine the development of the sediment. so scientificallyassess the cave environmental carrying capacity, reasonably develop cave tourism resourcesare is significant. The ceiling of the Caoxian cave was full of algae, fungi, ferns and otherplant in light source range. The breeding of these plants will have corrosive effect tosediment.. Transformation of the lighting system inside the cave, the prevention and control oflighting plant breeding is an important job. |
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