Feng Jinglan and Danxia Landform

Du Haiyan, Shi Jing'an Lizhi

(China Geological Library)

Feng Jinglan is a famous geologist and educator in my country. pioneer. Feng Jinglan has carried out a lot of practical work in the areas of neotectonic movement, landforms, mineralization control, mineralization laws and geological education in the Guangdong and Guangxi regions, the Yellow River and Heilongjiang basins, and has expressed unique and profound insights on many aspects, not only at the time It has foundational and pioneering significance and still has important guiding significance today.

1. Life of Feng Jinglan

Feng Jinglan was born in Tanghe County, Henan Province in 1898. He studied in the United States in his youth and returned to China after completing his studies in 1923. He has been engaged in geological science and geological education for a long time and has worked hard for more than 50 years. He is one of the pioneers of modern geology and geological education in my country. Feng Jinglan has done a lot of foundational work in modern mineral deposit science in my country, especially in the geology of gold, copper and other mineral deposits, and has been praised and respected by the academic community.

In 1918, Feng Jinglan went to the United States to study at public expense and attended the Colorado School of Mines. He graduated in 1921 with a degree in mining geological engineering. In the same year, Feng Jinglan was admitted to the Graduate School of Columbia University in the United States to study mineral deposits, petrology and geology. He received a master's degree in 1923. He returned to China that year and embarked on the long road of dedicating himself to the motherland's geological education and mineral geological exploration.

From 1923 to 1927, Feng Jinglan served as lecturer, professor and director of the Department of Mineral Geology at Henan Zhongzhou University. In conjunction with his teaching work, he studied the sand dunes along the Yellow River near Kaifeng. This was the beginning of Feng Jinglan’s indissoluble bond with the management and development of the Yellow River. In 1927, Feng Jinglan went to the Heishanzhai watershed in Changping, Hebei Province to investigate the geology of gold mines. This is one of the earliest modern gold deposit geological works in my country.

From 1927 to 1929, Feng Jinglan served as the technical chief of the Guangdong and Guangxi Geological Survey Institute (Guangzhou). He successively worked with Zhu Huisheng, Le Sen and other colleagues to investigate the geology along the Guangzhou-Kowloon Railway (1927). They also conducted comprehensive inspections of the geology and mineral resources in northern Guangdong (at the end of 1927) and the geology and mineral resources along the Guangzhou-Shaoguan section of the Guangdong-Hankong Line (in 1929).

From 1929 to 1933, Feng Jinglan served as a professor at Beiyang University, teaching courses in mineralogy, petrology, mineral deposits and general geology. At the same time, he was hired by Tsinghua University to teach part-time at Tsinghua University. During this period, Feng Jinglan investigated the geology and mineral resources along the Shenhai Railway, Xuanlong Iron Mine in Hebei, and the geology of northern Shaanxi. At this time, Feng Jinglan was not only committed to domestic geological education and geological survey practice, but also paid attention to international geological trends, and tried his best to introduce main information to the country to improve the level of geological work. In addition to introducing the progress of foreign volcanology research, he also edited the book "Prospecting" in order to promote the development of my country's mineral resources. After the book was published by the Commercial Press in 1933, it was reprinted more than once and has been widely distributed. The book is comprehensive and concise, introducing the advanced international experience at that time. It can be said that this book is the predecessor of the current "Geology of Prospecting and Exploration". In the same year, he also published the article "The Theory of Radioactivity and Geothermal Energy".

Since 1933, Feng Jinglan was employed at Tsinghua University and taught in the Department of Earth Science, teaching mineral deposits, mineralogy and petrology. During the summer vacation from 1933 to 1937, Mr. Feng investigated the geology, rocks and minerals in Pingquan, Hebei, Datong, Shanxi, Zhaoyuan, Shandong and Mount Tai. Feng Jinglan is one of the pioneers in the geological research of Zhaoyuan Linglong Gold Mine. At this time, Feng Jinglan guided Mr. Wang Zhi to conduct research on the geology of Mount Tai, Shandong. This was the earliest research work on Precambrian topics in China.

During the Anti-Japanese War, Feng Jinglan moved with the school and searched for mineral resources for the Anti-Japanese War. At the beginning of the Anti-Japanese War in 1937, Tsinghua University moved south to Changsha and then to Kunming. Feng Jinglan served as a professor at Southwest Associated University, and concurrently served as dean of the School of Engineering and director of the Mining Department of Yunnan University from 1943 to 1945. During this period, Feng Jinglan was not only in charge of academic affairs but also devoted himself to copper mine geology and other work in Sichuan, Kangxi, and Yunnan provinces to support the Anti-Japanese War.

At that time, there was a lot of field work, such as the copper mine in Yongsheng area of ​​Yunnan Province in the autumn of 1938, the Yingjing copper mine in Xikang and Pengxian copper mine in Sichuan Province in 1939, and the copper mines in eastern Xikang and western Sichuan in 1940. , 1942 Geological and mineral surveys of various copper mines in Dongchuan, Yunnan and Lunan, Yunnan. Based on the above work, Feng Jinglan completed the book "Minutes of the Sichuan-Kangdian Copper Mine" in 1942. The book won the Academic Award from the Ministry of Education at that time.

In the subsequent "Problems of Supergene Enrichment in Sichuan-Kangdian Copper Mines", Feng Jinglan discussed the phenomenon of supergene enrichment in the copper mines in the above three provinces and the geological and geographical conditions for its formation. In addition, Feng Jinglan has also done many other mineral geological surveys, including the Xikang Huili Tianbaoshan lead-zinc mine in 1941 and the geology and minerals of Baoshan, Changning, Shunning and Menghua in the western section of the Yunnan-Burma Highway, and the Yunnan Road in 1942. The geology and mineral resources of Nan County, the geology along the Yunnan-Burma Railway in 1944, the geology and mineral resources of Yuxi County, Yunnan Province, and the geology of Chenggong County, Yunnan Province in 1945. He also wrote articles discussing the future of the Sichuan-Kangdian copper mining industry, the mining period of Yunnan, and the mineral areas and Yunnan geology, mineral resources and mining, etc.

Feng Jinglan has always paid attention to water resources conditions and water system issues. In 1941, he published "The Asymmetric Characteristics of China's Water Systems", which discussed the asymmetric characteristics of the Huaihe River, Weihe River, Haihe River, Liaohe River, Tarim River, Xijiang River and Yangtze River, and analyzed their causes. In 1946, he published "Geography of Dali County, Yunnan" and believed that there were watershed migration and diversion phenomena in the area. It was possible to use the geography characteristics to dig canals from Diantou, and put forward outstanding insights into the development of water power and water conservancy resources.

After the founding of the People's Republic of China in 1949, Feng Jinglan, who was over fifty years old, became even more youthful and energetic. He actively participated in the construction of the motherland and taught successively at Tsinghua University and Beijing Institute of Geology. He was also ordered to travel among the rivers and mountains of the motherland to engage in mineral exploration and hydraulic resources investigation and research.

In June 1951, Feng Jinglan was appointed as a member of the China Geological Work Plan Steering Committee and participated in the comprehensive planning of the geological work in New China. In 1954, Feng Jinglan wrote the article "Characteristics and Problems of the Yellow River". That year, Feng Jinglan was hired as the leader of the Geological Group of the Yellow River Planning Commission. In December of the same year, Feng Jinglan participated in the preparation of the geological part of the "Technical Investigation Report on Comprehensive Utilization Planning of the Yellow River". The article specifically pointed out: Soil and water conservation work in the upper and middle reaches of the Yellow River must be promoted on a large scale and actively.

In 1956, Feng Jinglan participated in the national 12-year scientific development planning work. In the same year, he was selected as an activist for socialist construction and attended the National and Beijing Advanced Workers Congress. In 1957, Feng Jinglan was elected as a member (academician) of the Chinese Academy of Sciences, a first-class professor, and had many part-time jobs in society. These reputations and statuses were not what he deliberately pursued, but the recognition of all his work results by the society and the geological community. .

Feng Jinglan devoted himself to the geological cause of the motherland for 53 years from 1923 when he returned to China after completing his studies to his death in 1976, and made many contributions, including the geology of Guangdong and Guangxi, Danxia topography, Sichuan-Kangdian Copper Mine, Henan He also conducted a lot of practical work on the geology and landforms of the Yellow River and Heilongjiang basins, neotectonic movements and engineering geology. He compiled mineral deposit science textbooks and worked on mineralization theory (formation theory). He also made important contributions in terms of mineral sealing theory, mineral deposit formation, mineralization control and mineralization laws, etc. These are models for future generations.

2. Feng Jinglan’s discussion of Danxia landform

1. He discovered the unique landform of “Danxia landform” and discussed it in detail in his 1928 article

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From 1927 to 1929, Feng Jinglan served as the technical chief of the Geological Survey of Guangdong and Guangxi (Guangzhou). He and his colleagues conducted on-site surveys of the geology and mineral resources of Guangdong and Guangdong, and wrote the book "Geology and Mineral Resources of Nanxiong in Renhua, Qujiang, Guangdong" (Feng Jinglan and Zhu Feisheng) , "Geology along the Guangdong-Han Line" (Feng Jinglan, Zhang Huiruo), "Geology of Luochengsimen Coalfield in Qianjianghe Mountain, Guangxi" (Feng Jinglan, Lesen), "Geology of Northeastern Guangxi" (Feng Jinglan), "Geology and Mining Summary of Guangdong and Guangxi" ( Feng Jinglan), "Geological Problems in Guangdong and Guangxi" (Feng Jinglan), "Some problems in the geology of Kwangtung and Kwangsi" (Feng Jinglan), etc. This is the first modern geological survey work carried out by the Chinese themselves in Guangdong and Guangxi.

In the winter of 1927, Feng Jinglan and others inspected and studied the topography, stratigraphy, structure and mineral resources of this area during the geological survey in northern Guangdong, paying special attention to the Tertiary red sandy conglomerate system in the area. It is widely distributed and is most fully developed in Danxia Mountain in Renhua County, so it is named "Danxia Formation". This layer is 300 to 500m thick and gentle in appearance. After weathering and erosion, it forms cliffs with numerous peaks everywhere, forming a unique topography, the "Danxia topography".

Feng Jinglan and others studied this at the time, and described this topographic (landform) characteristics, The distribution, formation, etc. are all explained in detail and are excerpted as follows:

“The most easily identifiable feature of the red rock series gravel, sandstone, shale and laterite is its blood-red color, so it is named red. The name of the rock system refers to the red rock system in this area, located on top of various rocks, covering all rocks, and widely distributed, south of Renhua, north of Qujiang, west of Jilong, east of Dajing, and on the Nanxiong Plain Inside, beside the Zhenshui River Valley, there are red rock formations everywhere, with a total area of ​​no less than 5,000 square miles.

Although the red rock formations are characterized by their color, they are the same from top to bottom without much difference. The thickness of its constituent materials is very different. In short, it can be divided into upper and lower parts: the lower part is mainly conglomerate and red sandstone with cross bedding, with a foot or several inches of red shale and laterite in between. Mainly, there are sandstone or gray sandstone layers that are several minutes or even several feet thick. The thickness of the upper and lower parts varies from place to place due to the relationship between sedimentation and erosion. The area near Danxia Mountain is almost entirely in the lower part of the Red Earth System. It is about 300 meters thick. The red conglomerate system in the Cangshi Yangli Rock and other places in the northwest of Nanxiong is also 300 meters thick. The red rock system in the lower part of Nanxiong City is the thinnest, only a few dozen meters. The lower part of the system is most developed in the Nanxiong Basin. It is about three to four hundred meters thick. However, because it is too loose, it is easy to wash away. After modern washing, the thickness left behind is also very consistent.

Named after a representative area, the upper part of the red soil and red shale is about three to four hundred meters thick, which can be called the Nanxiong layer. It is most developed near Nanxiong and the lower part is about three hundred meters thick. The red conglomerate sandstone can be called the Danxia layer. It is most developed in Danxia Mountain, thirty miles south of Renhua City. The Danxia layer tilts between ten and fifteen degrees, and it is unconformable with the lower layer to form Danxia. The materials of the layers are also inconsistent, depending on the rocks they come from. In short, wherever they are close to the Huanggangling rocks, the gravels in the red conglomerate are mostly quartz or siliceous discs, which is obviously due to The rocks of the Huanggangling Series or the Meiling Series were eroded. Wherever near the limestone outcrops, there are limestone blocks among the conglomerate in the red conglomerate. There are many examples of contact with granite at Danxia Shixing and other places. , granite and gravels that have turned into feldspathic sandstone are common. Various gravels are often combined with red clay, so at first glance, the sandstone grains are mostly siliceous, with different thicknesses, and are often mixed with red clay. Red clay, sandstone in contact with granite, is often mixed with kaolinized feldspar grains, which are obviously derived from direct weathering of granite, with very little other materials mixed in. The interlayering of sandstone sometimes has a fine texture, like red. The name of Jinyan Rock (at the foot of Danxia Mountain, about two miles away from Danxia Mountain Temple) is derived from this. In the Jinyan Buddhist cave, there are solid red mud sandstones that protrude into cracked patterns and are set in alternating layers of sandstone. The edges are like lace under a brocade curtain, and they seem to be the remains of material filled in sun cracks. However, the local people already believe that it is a creation of heaven and earth, and it is magical and incomparable.

The Nanxiong Formation in the upper part of the red rock system. , mainly made of blood-red clay (according to analysis results, the iron content is about 3%) and shale, with thin layers of sandstone, or very rare calcareous sandstone and conglomerate. All rock layers have a gentle slope, about Between the tenth and fifteenth degrees, they are integrated with the Danxia layer below them, and then eroded, each becomes a significant small class of land, which is more significant in the Nanxiong Plain. The red soil on the ground is weathered and broken into loose particles, as big as millet. After rain, it becomes loose like sand. The shape is not very cohesive, which is quite unique. And within the red soil, you can see small calcareous veins and cross-clay layers as thin as paper, especially in the loose red soil, which seem to be formed by the immersed calcareous solution filling the cracks in the red soil.

The location of this red rock series and its relationship with the underlying rocks suggest that it is the latest in age, so there is no doubt that it is a product of the Tertiary Period. It is also believed that the Nanxiong Formation belongs to the Tertiary Age than the Danxia Formation. The Nanxiong layer was dated to the late Tertiary period. The Danxia layer and the Nanxiong layer seemed to have been weathered and deposited in a hot and humid climate. Therefore, they were violently oxidized and turned dark red. They seemed to have been deposited in shallow water, so they were sun-dried. Various structures of gaps and interaction layers. The materials it consists of seem to come from nearby without long-distance migration, so the separate effects and sorting actions are not very obvious, and they are often similar to nearby materials. The Danxia layer can represent the erosion and sedimentation when the mountains were first uplifted in the early Tertiary Period, so the material is relatively coarse. The Nanxiong layer can represent the gradual flattening of the ground, erosion and sedimentation in the late Tertiary Period (Paleo-Neogene), so the material is finer.

Both seem to belong to continental deposits in basins or river valleys, so there are very few fossils and the red rock series has many layers. It is imaginable that the sedimentary conditions at that time were complicated.

The red rock system is widely distributed in Guangdong Province. The red clay in the suburbs of Guangzhou City seems to be equivalent to the Nanxiong Formation in this area. The red conglomerate sandstone in Shixia Mountain in Shixia Village on Guangjiu Road and the red conglomerate sandstone in Humen Mountain at the Pearl River Estuary seem to be equivalent to the Danxia Formation in this area. "

In the "Topography" section of the same paper, there is an incisive and detailed research and analysis on the relationship between this terrain and geological structures, terrain and rocks, and the origin of this terrain. The excerpt is as follows: < /p>

“The relationship between topography and geological structures is quite obvious in this area. At the end of the Mesozoic Era or the beginning of the Tertiary Period, due to the intrusion of granite and the uplift of the Dayuling Mountains, a mountain range oriented slightly to the northeast, southwest, east and west was formed. At the same time, south of Nanxiong, there seemed to be igneous rocks intruding, and the strata were uplifted, resulting in the formation of the Tertiary Period. The red basin of the 19th century, and the sediments in this red basin. Later, due to the rise of the red basins in Danxia Nanxiong, the downstream rivers in the basins eroded downwards and carved into the Tertiary red rock formations, creating a canyon with a depth of about a thousand feet and a unique scenery. The relationship between this large structure and topography is formed by the victory of Wumaguicao in Abang Mountain of Danxia Jinyan. For example, the Meiling Longitudinal Valley and the Shaoguan Fault Valley opened up tunnels, and their impact on the terrain and people is not superficial. Details can be found in the structure chapter.

The rock formations of the two series of Huanggang Ridge and Meiling are alternating sandstone and shale, which are easy to erode, so the hills and ridges formed are all very flat, and the slopes of the hillsides are often below fifteen degrees. However, the places in contact with granite are affected by contact metamorphism and are solid and resistant to erosion, and can also become high cliffs. However, it is only limited to local areas, and there is no vast area of ​​Huanggangling or Meiling series rock formations. Instead, it presents a peculiar terrain, such as the red rock formations. The Permian and Carboniferous limestones in this area are at lower levels and are not widely distributed. There are outcrops due to erosion or faults, such as Meilingxia Scarab Rock, Zhonggu Rock, and Linglong Rock in Shixingnan. The rocks, goose mouth, etc. are all exquisite and small, which is completely different from the tall and strong terrain formed by red conglomerate, with neat edges and corners, standing on all sides and flat top. Moreover, the slope of its slopes is mostly between 35 degrees and 55 degrees. Except for faults, it is rare for cliffs to be formed by erosion. Intruded granite contains a lot of feldspar phenocrysts and is easily weathered and broken, so the mountain shape formed is not very unique. However, because of its large size and high elevation, it is difficult to remove the overlying rock formations and has not been directly affected by erosion for a long time. Therefore, it is still a great and powerful mountain today. On the water-removing boat, or in the Nanxiong and Shixing plains, looking forward, backward, left, and right, you will see that all the mountains are huge and strong, with granite reaching into the clouds; and those adjacent to the mountains, forming their edges, are also water-formed rocks; the volume of the water-formed rock mountains is relatively large. Those with large, gentle slopes are Huanggangling or Meiling systems; those with neat, flat upper parts and overhanging cliffs are red conglomerate; and those in valleys and plains have intermittent hills and ridges with slopes ranging from Huangshan to Huanggang. The Permian Carboniferous limestone between the Meiling Mountains and the Juese Rock Mountains is the Permian Carboniferous limestone. By inferring the rocks from this topography, the geology within dozens of miles can be understood at a glance. ”

In summary, based on the common language and Cihai’s interpretation of the word “discovery”, from 1927 to 1928, Feng Jinglan and others investigated and researched and discovered the Danxia topography (morphology). They discovered the Danxia topography. The discussion of topography attracted the attention of geologists and began more research.

2. Further in-depth research and expression of "Danxia layer" and "Danxia topography"

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In 1939, Feng Jinglan discussed the "Division of Red Rock Formations in Southeast China" published in 1935 in "Opinions on the 'Division of Red Rock Formations in Southeast China'" and once again discussed the "Danxia Formation" , "Danxia terrain" has been further studied and described. The geological term "Danxia terrain" was named and used many times in the article:

"...There is no paleontological aspect or structure. Significant evidence in this aspect can also be used as the basis for field investigation based on rock properties, terrain characteristics, strata, and distribution. Therefore, during the investigation of Danxia Mountain and Nanxiong Basin in the 16th year of the Republic of China, the red rock formations in northern Guangdong were divided into Danxia Formation and Nanxiong Formation. The Danxia layer represents the lower part of the red rock layer, which is dominated by conglomerate sandstone, and the Nanxiong layer represents the upper part of the red rock layer, which is dominated by shale and sandstone. Although continental sedimentation is highly variable, the Danxia Formation is often not without a little shale, and the Nanxiong Formation is also indispensable with conglomerate. However, in the well-developed Danxia Formation and Nanxiong Formation, from a topographic point of view Look, at least in northern Guangdong, it’s absolutely different.”

"In the winter of the 16th year of the Republic of China, I entered the Nanxiong Basin from the northwest side of the Nanxiong Basin, then crossed the Dageng Ridge from the northeast side of the Nanxiong Basin to Jiangxi, then turned around and returned to Nanxiong. The southwest corner of the Nanxiong Basin goes out to Shidian; during a few days of resting in Nanxiong, we even reached the Nanshan Mountain of Nanxiong. Therefore, all aspects of the northwest, southwest, northeast, and south of the Nanxiong Basin have been investigated and found. There is a basal conglomerate (Danxia layer) in contact with Paleozoic shale or granite, and a loose shale sandstone layer (Nanxiong layer) above it. Nanxiong City) and the gradual changes between its upper and lower layers are quite obvious."

"The Danxia Basin I saw is surrounded by Paleozoic limestone. In the real Danxia rock layer, there is limestone conglomerate. There are many, the strength of bonding is self-strengthening, and the inclination angle is small in the center of the basin, so it is easy to cut the gently sloping limestone like Guilin, Yangshuo or Lunan to form cliffs. The edges of the Nanxiong Basin are granite (east, southeast, south and south). Northwest) and shale (Northeast, Southwest), not very cohesive, not much gravel, not thick, not solid, and at the edge of the basin, the slope is large, so it is not easy to form a special Danxia terrain...that is, in the south On the edge of the Xiong Basin, the thickness of the Danxia conglomerate is different, and the degree of perfection of the Danxia terrain is also different. In short, in the northwest of the Nanxiong Basin, the conglomerate layer is thicker, and the resulting Danxia terrain is also thicker. Next, the northeast and southwest of the Nanxiong Basin are medium in layer thickness and topography; followed by the south and southeast, the layer thickness is the smallest and the Danxia topography is the least developed."

" In short, the Danxia terrain is one of the characteristics of the Danxia layer..."

"...Mazu Cliff is unique and has the characteristics of Danxia terrain. It is also a conglomerate layer and coarse sandstone, which should be Feng Zhidan "Xia layer..."

3. The development of "Danxia landform" research

1. Early research

From 1927 to 1929, Feng Jinglan served as the Guangxi Geological Survey Institute (Guangzhou) Technical Zheng, he and his colleagues worked with Zhu Huisheng, Le Sen and other *** to investigate the geology along the Guangzhou-Kowloon Railway (in 1927, this was the first modern geological survey conducted by the Chinese themselves in Guangdong and Guangxi), Guangdong Comprehensive investigation of geological and mineral resources in the North (end of 1927) and the geological and mineral resources along the Guangzhou-Shaoguan section of the Guangdong-Hankong Line (1929), etc. They conducted a detailed investigation and study of the terrain, stratigraphy, structure and mineral resources in northern Guangdong, and fully noted the widespread distribution of Tertiary (Paleo- and Neogene) red sandy conglomerate layers in the area. This layer is most fully developed in Danxia Mountain in Renhua County, so it is named "Danxia layer". The Danxia layer is 300 to 500m thick and is produced in a gentle shape. After weathering and erosion, it forms cliffs with strange peaks everywhere, forming a unique topography. In 1928, Feng Jinglan discovered widespread Tertiary (Paleo-Neogene) (65 million to 1.65 million years ago) red sandy conglomerate layers while conducting geological surveys in Shaoguan, Guangdong. This type of rock layer was most developed in the Danxia Mountain area of ​​northern Guangdong. Completely, due to long-term erosion by running water, wind, etc., it has formed fortress-like peaks and peak clusters as well as various strange rocks, stone bridges and caves. Feng Jinglan, who returned from Columbia University with a master's degree in geology, realized that this was a unique landform and began to study it.

In 1928, Feng Jinglan noticed the widely distributed Tertiary (Paleo- and Neogene) (65 million to 1.65 million years ago) red sandy conglomerate layers in Renhua County, northern Guangdong, my country. In the Danxia Mountain area, the 300-500m thick rock formations have been eroded by water, wind and other weathering forces, forming fortress-like peaks and peak clusters, as well as various strange rocks, stone bridges and caves. Feng Jinglan realized that this was a unique landform and named the red gravel layer forming the Danxia landform the Danxia layer.

The research on "Danxia Landform" started due to geological survey. China's first generation geologists, Feng Jinglan and Zhu Feisheng, conducted geological surveys in Qujiang, Renhua, Shixing, Nanxiong and other counties in Shaoguan City in 1928. In order to fill in the geological map, the strata must be divided, so they conducted geological surveys in Renhua A set of red clastic rock series exposed in the Danxia Mountain area is named "Danxia Formation" and its age is designated as the Tertiary Period. "Danxia layer" was first used as a geological term. Feng Jinglan gave a vivid description of the rock combinations, landform characteristics, formation reasons, and distribution examples of the Danxia Formation: "The relationship between terrain and rocks is more obvious. The lower part of the Tertiary (Paleocene and Neogene) red rock formations is often deep. The solid blocks of sandstone and conglomerate alternate with each other. After erosion, the cliffs are as straight as a man-made, solid and majestic fortress. It is unknown that it was created by heaven and earth.

Nanxiong Cangshi Village, Yangli Rock, Renhua Jinyan, Danxia Mountain, Rentou Stone, Qianjinzhai, Shutang Rock, Duanshi Rock, Guanyin Rock, Bijia Mountain, Matou Village, Guitou Mountain of Qujiang, Gua Bangshan Mountain, Sanfengjie, Wumagui Cao, etc. are all formed by the erosion of this kind of rock. The peaks and cliffs are steep, the rivers are rushing, the red cliffs are standing on all sides, and the green trees are growing on them. It is a wonder of Lingnan. "Although Feng Jinglan did not propose the term Danxia landform, he has made an incisive discussion on the characteristics of Danxia landform, which laid a solid foundation for the proposal of Danxia landform.

Feng Jinglan's identity at the time was the Geology Department of Sun Yat-sen University The Guangdong and Guangxi Geological Survey Institute (equivalent to the current professor), in the 1920s and 1930s, was the initial stage of modern geography in my country, and a series of studies in Lingnan geography were pioneers.

2. In-depth research

In 1928, when Feng Jinglan and others were investigating the topography, stratigraphy, structure and mineral resources in northern Guangdong, they named the typical red sandy conglomerate layer in Danxia Mountain the "Danxia layer", and its age was determined to be The Tertiary Period (Paleo-Neogene) analyzed the fortress-like mountains and various terrains developed by the Danxia layer under the influence of long-term erosion, weathering, gravity and other external forces, and was the first to vividly describe this unique landform. . In a discussion article with Mr. Chen Guoda in 1939, Feng Jinglan began to use the taxonomic term "Danxia terrain" many times. Feng Jinglan first proposed the geological term "Danxia layer" to describe the rock combinations of Danxia layer. The landform characteristics and formation causes are vividly described, laying a solid foundation for the proposal of Danxia landform.

Danxia landform is mainly distributed in China, the western United States, Central Europe and Australia, with the largest distribution in China. Guangdong. So far, more than 780 Danxia landforms have been discovered in China, distributed in 26 provinces and regions. The Danxia Mountain in the northeast of Shaoguan City, Guangdong Province is characterized by red Danxia and is composed of red gravel continental sedimentary rocks. It is the world's "Danxia". "Landform" named place, the research on stratigraphy, structure, landform, development and environmental evolution is the most detailed and in-depth among the Danxia landform areas in the world.

In the 1920s and 1930s, Chinese geologists Feng Jinglan proposed the "Danxia layer" during his investigation in the Danxia Mountains in northern Guangdong. It is a special rock landform named by Chinese geologists. Its classic definition can be simply described as a continental red bed landform with steep cliffs. Chinese Geology. In 1928, the scholar Feng Jinglan named the "Danxia layer" after the Danxia Mountains in Guangdong; in 1954, "topography" was renamed "geomorphology", so the "Danxia topography" was correspondingly called "Danxia landform". With a history of more than 80 years, dozens of domestic universities and research institutes have been involved in research in various related fields, forming a relatively complete research system on Danxia landforms in China, from tropical to temperate zones, from humid areas to arid areas, and from coastal areas. Danxia red layers are distributed from hilly plains to the Qinghai-Tibet Plateau, and Danxia landforms of various origins have developed, forming unique natural geographical landscapes and beautiful natural scenery.

IV. Conclusion

In the 1928 paper "The Geology and Mineral Resources of Nanxiong in Renhua, Qujiang, Guangdong" (Feng Jinglan and Zhu Huisheng) named the red layer characterized by the unique landforms of Nanxiong Danxia Mountain and other areas as "Danxia layer", although The Danxia terrain was not named, but Feng Jinglan's description and research on its origins clearly clarified their properties. In 1939, it was named Danxia terrain. In the same year, Chen Guoda used the term "Danxia topography" in his article "Geology of Gongshui Basin in Jiangxi" but did not discuss it. Chen Guoda and Feng Jinglan were thousands of miles apart. It was very difficult to exchange documentary information at that time, but each used the geological term "Danxia topography" in their works. Feng Jinglan clearly pointed out: "The rocks formed by this landform are the red beds of the lower Tertiary period, which are deep and solid massive sandstones and conglomerates. Its topography is characterized by steep rock cliffs, as straight as man-made solid fortresses... There are 15 peaks, cliffs, and red cliffs standing on all sides. "It was formed by water erosion. There are 15 examples of them, and Danxia Mountain is one of the most wonderful ones. Chen Guoda used the term "Danxia terrain" based on Feng Jinglan's description. In 1943, Zeng Zhaoxuan proposed that 20m platform, 200m quasi-plane and vertical joints have an important impact on the development of Danxia topography. In 1946 and 1948, Wu Shangshi and Zeng Zhaoxuan further discussed the geology and topography of the red rock series in northern Guangdong. In recent years, Huang Jin has published many papers on field investigations and further in-depth research on Danxia Mountain and other places... The investigation and research are continuing to deepen. The scope of investigation and research is also expanding day by day. Currently, there are 6 typical areas and more than 780 Danxia landforms discovered in China, distributed in 26 provinces (autonomous regions and municipalities).

Danxia Mountain in Shaoguan, Guangdong is the world's "Danxia Landform" named place, with the most detailed and in-depth research on stratigraphy, structure, landform development and environmental evolution. Similar landforms have been discovered in other countries around the world. Geoscience terminology has also been adapted to "Danxia landform" from the "Danxia landform" before the 1960s in line with international standards. "Chinese Danxia" has been listed as a world famous natural heritage. The unique natural heritage of Danxia landform is bringing richness and beauty to life to more and more people in China and around the world. This is the greatest joy for Feng Jinglan and the people who have worked or are working hard and ingenuity on this.

References

[1] Liu Haolong. Brief summary of Professor Feng Jinglan’s life and achievements [J]. Modern Geology, 1998(4): 3～6

[ 2] I offer treasures for the motherland: Album of Academicians of the Land and Resources System [M]. Beijing: Geological Press, 2009, 97～98

[3] Feng Jinglan, Zhu Xiangsheng. Shixingnan, Renhua, Qujiang, Guangdong Xiong Geology and Mineral Resources [J]. Geological Annual Report of Guangdong and Guangxi Geological Survey, No. 1: 29~51

[4] Feng Jinglan. Opinions on the division of red rock formations in southeastern China [J]. Geological Review , 1939 (3～4): 173～192

[5] Chen Anze. Discussion on some issues of Danxia landform [C]. See: Theory and Practice of Tourism Geoscience (Collection of Tourism Geosciences, Volume 11 ).Beijing: China Forestry Press, 2005, 88～92