The stonemasons in history might never have imagined that,in order to obtain stone materials,many quarrying relics left on the earth would become ancient and fantastic places of interest and scenery in later generations.

Stone is one of the oldest building materials of mankind.Before gunpowder was used for quarrying,stone mining was done with hand tools.Following the texture of the rock,drills and hammers were used to chisel the mountain body,and the cliffs and caves left on the mountain body formed some special landform landscapes.If the quarry is related to important monuments or events at that time,it can awaken people's deep cultural recollection and become a historical site for people to remember the past,such as the ancient Aswan mine in Egypt famous for its unfinished obelisk,the Dionyssos Quarries in the Pendelikón Mountains in Greece as the source of the Parthenon stone,and the Yangshan stele mining site in Tangshan,Nanjing.There are also some quarries that have been preserved by chance.After years of panning,they have become one with nature,just like a natural creation.After the landscape adjustment and processing of later generations,they have become rare landscapes,such as the East Lake in Shaoxing and Changyu Cavern in Wenling,Zhejiang,China.

Since the invention of gunpowder,blasting quarrying has gradually replaced manual digging.With the continuous improvement of quarrying efficiency,quarrying has gradually evolved into an extremely extensive industry.The wound surface of quarrying is getting bigger and bigger,and the damage to the land surface is getting increasingly serious.Because quarrying brings a series of environmental problems such as deforestation,soil loss,water pollution,loss of biological habitat,and the risk of geological disasters,the abandoned quarry pits are considered to be scars on the earth.

Quarry pits are usually required to be re-greened for environmental restoration.Due to the difference in geology,landform,climate,type of stone obtained,mining method,mining cycle and mine idle time after the mine is closed,the condition of each quarry pit is also different.Under certain circumstances,the quarry after the mining stops will start the ecological self-repair process.After being hit by wind and rain,the dangerous rock will collapse,the stone wall will gradually become stable,and some pioneer plants will sprout and grow from the stone crevice and continue to multiply.However,since the quarrying process has removed the original vegetation and surface soil layer,there are often only rock layers and slag left in the quarry,and especially on the smooth stone walls,there is hardly any soil,so only relying on natural processes to restore the quarry pit vegetation and form a lush landscape usually takes a long time.

If we only see the serious damage to the surface and the ecological environment caused by the quarry,then trying to eliminate or hide the quarry landform will inevitably become the ultimate goal of ecological restoration of the quarry pit.Five years ago,when I was designing the 7 quarry gardens in Nanning Garden Expo Park,I was advised: to either use some excess earthwork in urban construction to fill these quarry pits to restore their original landforms and vegetation,or take corresponding engineering measures to anchor the steep rocky cliff side slopes and create opportunities for covering soil on the cliffs,so as to grow plants and restore the green pit.I did not accept these suggestions,because the former was too expensive and unfeasible,while the latter was too intensive,and it would even bring about further damage to the landscape,and the restored vegetation lacked natural flavor.In fact,it is not necessary to take high-intensity engineering measures for the ecological restoration of quarry pits without personal and property safety hazards.It is only necessary to carry out certain risk elimination and avoidance treatments on the steep walls of the pits,supplement artificial soil in the flat area,follow the natural process,and grow corresponding plants,and it can speed up the restoration of the ecological environment of the abandoned quarry pits.

There is no doubt that the extensive quarrying method has caused serious damage to the natural landscape and ecological environment,but from another perspective,the mining of rocks also exposes the rock formations hidden inside the mountain to the outside.Unique,rough and precipitous landforms,such as giant barrier-style cliffs,precipitous cliffs,dangerous rocks,and craggy residual rocks,are cut out,and the water comes together to form quiet deep pools or lakes;at the same time,quarry pits are also a heterogeneous landscape completely different from the original environment,bringing diverse base sites and different habitat conditions,thus expanding the habitat types in the area;and this special landform formed under human action is related to local economic development and social changes.Therefore,many quarrying pits that seem to be devastated have the potential to form unique landscapes with deep humanistic colors.If we can make full use of the unique characteristics of the quarry pits,on the premise of ensuring safety,we can excavate and strengthen the landscape characteristics of the quarry,restore the ecological environment of the quarry,create a special habitat,reorganize and strengthen the pit space,reuse,transform the quarry into a unique landscape that displays human mining relics,reflect the historical connotation of mining development,and conduct activities such as tours,recreation,and popular science education.Thus resourcedepleted quarries can once again develop new values,producing comprehensive ecological,social,economic and aesthetic benefits.

There are endless possibilities for the reuse of abandoned quarry pits: the pits can be transformed into citizen parks,such as the Parc des Buttes-Chaumont in Paris;they can be renovated into landscape sceneries,such as the Mining Pit Garden in Shanghai Chenshan Botanical Garden,and Luoxia Pond,Junya Pool and Feipu Lake in Nanning Garden Expo Park;they can become scenic spots,such as the Quarry Pit in Jinyun,Zhejiang;become botanical gardens,such as the Butchart Gardens in Canada,the Rock Garden,Water Garden and Terrace Garden in Nanning Garden Expo Park;become open-air theaters,such as the St.Margarethen Quarry in Austria;create resort hotels,such as InterContinental Shanghai Wonderland;be formed as a wilderness in the city,such as Shuangxiu Garden in the Quarry Garden of Nanning Garden Expo Park;or be designed as a tourist attraction and holiday area,such as Nanjing Horticultural Expo Park.

The characteristics and conditions of quarry pits are different,and the restoration meth ods and functional transformation ways should also be appropriately selected.The ecological restoration,reuse and final appearance of the quarrying pits are all products of specific conditions.No matter how desolate the abandoned quarry pit is,it can and should become a new resource,not just an ugly scar on the earth that needs to be ecologically restored and that the traces of mining to be hidden.