A Comprehensive Study On The Weathering Of The Grottoes At The Fajing Temple In Xihe, Gansu Province

Gansu Xihe Fajing Temple Grotto was excavated during the Northern Wei Dynasty and has a history of more than a thousand years.It is one of the oldest cave temples in Longnan City,Gansu Province,and has important cultural relics and cultural values.Due to changes in the natural environment,economic development,and high population density around the Fajing Temple Grottoes,the preservation environment of the Grotto Temples has been affected.Especially in recent years,the grottoes cultural relics have gradually become more popular among tourists,coupled with local folk activities such as incense rituals during the Chinese New Year's days and folk festivals,the destruction of the various pollutions on the Grotto Temple have been significantly aggravated.Through a survey conducted in this area from January 2017,this article explores the various diseases that already exist in the grotto,and analyzes the sources of these diseases based on the objective environment of the grotto.In order to propose effective protection measures for cave temples,this article focuses on the analysis of rock properties,weathering simulation experiments on rock artifacts,and grotto cultural relics investigation and analysis.A Comprehensive analysis of the weathering mechanism of the weather of stone artifacts in the open air environment of the dry area to which the Fajing Temple Grottoes belong is taken.In further the author determines its maintenancelife in the future.To understand the weathering rate,the weathering degree and corrosion resistance of the cultural relics in the Grotto Temple,relevant simulation experiments are conceived.The work done and conclusions drawn in this article mainly include:(1)Using X-ray diffraction technology,polarized light microscope and portable XRF technology,the authorcarries out scientific and standardized detection and analysis of selected rock samples to effectively detect the main components and contents of weathering products in grotto diseases,and to get better understand the rock weathering mechanism of the body.The results show that the rocks in the cave temple are mainly composed of quartz,anorthite,calcite and kaolinite,and the rock sample has obvious porosity,which means that the cave is very vulnerable to weathering and erosion.For example,the migration of water in the rock body will cause the cations in the minerals to dissolve and migrate inside the rock.At the sametime,due to atmospheric pollution factors,the rock decomposes into various anions,such as sulfate ions,chloride ions,and nitrate ions.After the rock decomposes,cations are exchanged to form different kinds of soluble salts,and then they are lost with the water.(2)Through a four-month soluble salts simulation experiment,the author observes the changes in sandstone samples and various indicators of anions in rock samples,and realizes that the dissolution-crystallization-re-dissolution of soluble salts is the main factor for the occurrence of weathering diseases of stone cultural relics.(3)By conducting a freeze-thaw simulation experiment on sandy conglomerate samples for about 2 months,it was observed that the local temperature difference between day and night and the thermal expansion and contraction effects of solidification and dissolution of water have a considerable destructive effect on the rock samples.Wind erosion and weathering and the change in temperature difference between day and night are the main causes of cracks in the statues of Fajing Temple Grottoes.(4)The paper pulp desalination method is used to evaluate the desalination effect of rock samples,recognizing that through desalination to balance the internal salt content of stone cultural relics,it can slow down the erosion and damage of its internal and surface,thereby reducing the repeated erosion of soluble salts and slowing the solubility impact of salt on this major hazard in the preservation of stone cultural relics.According to the relevant results made by the simulation experiment,this article attempts to propose to reduce the impact of salt on the surface of the stone,strengthen the surrounding greening,reduce rain and snow erosion,and strengthen the protection of local cultural relics.Effective countermeasures and recommendations for longevity.