As far as geomorphology research methods are concerned, the initial research is limited by objective conditions and cognitive level, and the research mostly stays on descriptive perception, but these conclusions obtained through geomorphology investigation can provide theoretical guidance for quantitative methods. In recent years, with the new thinking of earth science and the progress of science and technology, remote sensing technology and quantitative calculation methods have been introduced into geomorphology research, and the dynamic erosion, transportation and accumulation are quantified by calculating the magnitude and rate of mountain uplift and erosion (Li Qiong, 2008; Fu Jianli, 2009; Yuan Cunyong, 2009; Jiang Yongbiao, 2065438+00; Cui Zhijiu, 2007; Yuan Wanming et al, 20 1 1). This is one of the development directions of geomorphology, and it is also a sign that a subject is maturing.
As far as geomorphology is concerned, it mainly focuses on Danxia landform, karst landform and granite landform. Danxia landform is a "national brand" for China to go global, and there are a large number of geological parks with Danxia landform as the main body in China. 20 10 In August, six geological parks, namely Longhu Mountain in Jiangxi, Danxia Mountain in Guangdong, Langshan Mountain in Hunan, Jiang Lang in Zhejiang, Taining in Fujian and Chishui in Guizhou, were tied together and successfully declared as the eighth world natural heritage in China under the name of "Danxia in China". Due to unique factors, China scholars are in the leading position in the research of Danxia landform in the world. Granite landform is the most important geological tourism resource in the world, and China is a country with the largest number, many types, high aesthetic value and outstanding characteristics of granite scenic spots in the world. Among the seven granite landforms in the world, China accounts for six. In July 2006, the first international conference on granite geology and geomorphology was held in Sanqingshan, Jiangxi. More than 100 granite geology and geomorphology experts from home and abroad attended the meeting, published special papers and set up a granite landscape research center. It can be said that China is an indispensable and important member in the study of global granite landforms.
The classification of granite landforms is one of the hot issues that geomorphologists often discuss, but it is difficult to reach a consensus. Among many granite geological and geomorphological scenic spots, there are many outstanding features such as different landscapes, diverse causes and numerous classifications.
As early as the 1960s, a famous geomorphologist in China divided granite into five types in his book Rock Topography: alpine granite landform, tropical granite landform, dry granite landform, stone egg landform and gully landform (note: the landform here is equivalent to landform).
Some scholars have classified granite mountain areas into five categories according to the dominant factors of genesis: water erosion landform of medium-high mountain granite in humid areas, erosion and accumulation landform of low mountain granite in humid areas, wind erosion landform of granite in arid areas, ice and snow erosion landform of granite in alpine areas and marine erosion landform of granite in coastal areas (Lu, 2007). In this scheme, Sanqingshan belongs to water-eroded granite in humid area.
Some scholars put forward a classification scheme of granite tourism landforms from the perspective of tourism service, which can be divided into * *11categories: (high mountain) peak granite landforms, (high mountain) cliff granite landforms, (low mountain) dome granite landforms, stone egg granite landforms, (low mountain) granite pillars and (low mountain) tower peak granite landforms. In this scheme, Sanqingshan Mountain belongs to the granite landform type at the peak (mountain).
Some scholars divide granite landforms into four categories from the perspective of weathering and denudation: chemical weathering crust, chemical weathering crust peeling, chemical weathering+uplift and undercut and physical weathering and denudation; It is further divided into eight sub-categories: erosion hilly valley type, outcrop rock type, medium and small outcrop rock type, medium and small concave type, residual stone egg independent giant peak type, uplift and undercut giant peak type, freeze erosion type and weathering-wind erosion type (Cui Zhijiu, 2007). Mr Cui Zhijiu classified Sanqingshan as chemical weathering+uplift and undercut.
"World Granite Landscape" (Migon, 2006) puts forward the classification scheme of eight main geomorphic genetic types corresponding to the world granite landscape, including union valley, multiple depressions, plains and low mountains, plains, multiple depressions, steep slopes and cut plateaus, and these types evolve with each other, as shown in figure 1. 1. Migan thinks that some granite landforms can have different genetic types, so although Sanqingshan can't completely correspond to a certain landform, the mountain shape of Sanqingshan does represent the "full slope" landform, and also has the characteristics of "cutting plateau" and "joint valley" landform.
According to Twidale( 1982) and Campbell( 1997), granite landforms can be divided into large landforms and small landforms: ① large landforms can be divided into four categories: boulder, island mound, full slope topography and granite plain. There are four types of boulders: core rocks, crushed gravel, rockery and slope drift gravel. Island mountain includes remnant mountain, bedrock remnant mountain and castle island mountain. The spire mountain includes two sub-categories: the surrounding hillside and the hilltop forest. Granite plains include buried and bare plains, eroded plains, piedmont eroded plains, quasi-plains and stepped plains. ② Small landforms can be divided into four categories: gentle slope, steep slope, karst cave, Taverny and cracked block. The gently inclined landform includes four subtypes: rock basin, mushroom stone, rock ring and shallow ditch. The steep slope landform is divided into six sub-categories: trumpet dip, bottom erosion dip, wave erosion platform, foothill depression, foothill angle and trench; Caves and honeycomb caves are divided into two subcategories; Cataclastic rocks include four subtypes: cataclastic rocks, flaky rocks, multilateral cataclastic rocks and displacement blocks.
Figure 1. 1 Granite Landscape Evolution Roadmap
(According to Migon, 2006)
Some scholars suggest that granite landscape series should be classified according to certain standards, and standard types should be established through comparative study (Yang Minggui et al., 2009; Yin et al., 2007), which is similar to the gold nail in the stratigraphic standard profile.
The development mechanism of granite landform is the research focus of granite landform. The classic definition of landform is "landform is the result of the interaction of external force and internal force on the earth's surface". Based on this, two sub-disciplines of climate geomorphology and structural geomorphology have been formed, and many teaching materials have been compiled along this line (Yang Jingchun et al., 2005; Zhang Genshou, 2005; Shu Gao et al., 2006). However, it is worth noting that this definition ignores the material composition of landforms-the proper position of rocks. Zeng (1960) thought that "landform is the expression of interaction between lithology and dynamics". To sum up, the granite landform is mainly influenced by structure, rocks, climate and other factors, and there is little difference with other types of rock landform genetic control factors. The three major control factors of granite landform development are also recognized by most geomorphologists (Campbell,1997; Yin, 2007; Pu Qingyu, 2007; Wei et al., 2007; Dong et al., 2007). To the specific landscape area, it only increases the dimension of time and space, and the specific situation is analyzed. Since granite is the basis of forming granite landform, we have to mention the research progress of granite (class) here. This is also the concrete embodiment of the intersection of granite geology and geomorphology.
Granite has always been one of the important research objects of geologists, and its understanding has also made important progress, which can be divided into the following stages.
In the first stage, Chapel & White (1974+0974) classified granites into I-type and S-type according to their material sources, while Chinese scholar Xu Keqin classified granites into three types: continental crust transformation type, syntectic type and mantle source type, which opened the prelude to the study of granite source rocks.
In the second stage, Pitcher (1979, 1983, 1997) combined the genetic types of granitoids with the tectonic environment, put forward the division of A-type granites, and the study of granites went deep into the discussion stage of the tectonic environment of rock mass formation;
In the third stage, the American Continental Dynamics Program (NSF, 1993) proposed that granite is actually the product of continental growth and the process of crust-mantle interaction. Chinese scholars also believe that the interaction between crust and mantle, especially the interaction between lower crust and lithospheric mantle/asthenosphere system, plays an important role in controlling the genesis of granite (David Hong,1994,2000; Mo Metaphysics, 2002; Wang Dezi et al.,1999; Wang Tao, 2000; Deng et al.,1996; Wu Fuyuan,1997; Xiao Qinghui et al., 2002), thus opening a new stage of studying the relationship between granite formation and continental growth from a new perspective of transporting mantle materials from the asthenosphere to the crust.
Through a lot of work, Chinese scholars have basically found out the time series and spatial distribution law of granitoids in China, which has the following characteristics.
First, the granitic magmatism lasted for a long time, from Archean to Cenozoic, with the Mesozoic as the climax. The granite exposed in Precambrian accounts for 1 1%, 37% in Paleozoic, 40% in Mesozoic and 12% in Cenozoic (Zhang Dequan, 2002). Each granite belt is composed of granites of multiple eras. For example, the Nanling granite belt moved from Proterozoic to Triassic in Paleozoic and Mesozoic, and reached its climax in Jurassic and Cretaceous. The Tianshan-Inner Mongolia-Daxing 'anling granite belt in the north began to be active in Proterozoic, reached its climax in early Paleozoic and late Paleozoic, and there was still weak magmatic activity in Cretaceous. Even in such a large-scale batholith, there are characteristics of multicycle evolution, and the Wanyangshan-Zhuguangshan granite batholith is a complex rock mass with many ages (David Hong, 2007).
Secondly, in space, China is one of the most widely distributed countries in the world, with an area of 86× 104km2, accounting for 9% of the land area. Archean to Late Paleozoic granites are mainly exposed to the north of Qinling-Kunlun Mountain. Mesozoic granites are mainly developed in the eastern and southwestern parts of Daxing 'anling-Taihang Mountain-Wuling Mountain. Cenozoic granites developed in Tibet and western Yunnan. Taking Helan Mountain-Longmen Mountain as the boundary, the spatial distribution of granite in the east and west is obviously different. Granite in the west is obviously distributed in a belt, controlled by plate subduction and collision, and developed in the junction zone between rigid blocks. The eastern part is mainly plane, controlled by extensional structure and developed in intraplate tectonic environment (David Hong, 2007). Guangdong, Fujian, Guangxi, Jiangxi and Hunan provinces have the largest exposed areas, with the granite areas of the former two accounting for 30% ~ 40% of the whole country and the latter three accounting for 10% ~ 20% (Cui Zhijiu, 2007). The so-called "the granite of the world looks at China, and the granite of China looks at the East".
Thirdly, in lithology, the composition of granitoid rocks in China has undergone an evolution from basic to acidic and alkaline from Archean to Cenozoic. According to the weighted statistics of 768 combined samples from 6080 samples of 750 large-area granite bodies, the content of SiO _ 2 and SiO _ 2 tends to increase, while the content of al2o 3, MgO, CaO and TFeO tends to decrease (Shi Changyi et al., 2007), which is consistent with the gradual transformation of the crust from siliceous magnesium to siliceous aluminum in the vertical direction (Cheng, 1994).
Fourthly, from the relationship with the tectonic environment, different tectonic environments often have different combinations of granitoids. Some granites are related to plate subduction and collision, and some granites are formed in the intraplate environment after collision. Accordingly, the combination of granite is also different. For example, the Mesozoic granite in Nanling is adamellite-feldspar granite-mica granite-granodiorite combination, the Mesozoic granite in North China platform is diorite-quartz diorite-granodiorite granite-quartz monzonite combination, the Himalayan belt is muscovite granite-tourmaline granite combination and the Gangdise belt is granite-granodiorite combination. Different rock assemblages determine that their petrochemical and geochemical properties are also significantly different (Shi Changyi et al., 2007). At the same time, due to the different tectonic environments in different periods in the same area, there are often overlapping, interlacing and transformation phenomena of different types of granites. For example, in the southeast coastal areas of China, due to the subduction of the Cretaceous Pacific plate, I-type granite along the coast of Fujian and Zhejiang was formed. After that, the tectonic environment changed from compression to extension, forming A-type granite, and the two granites closely coexist in space (David Hong et al., 2007).
Geological survey and geological research in northeast Jiangxi began in 1930s. This paper reviews the research history of geology in northeast Jiangxi and landforms in Sanqingshan Mountain.
1939, Liu Huisi, a geologist of the older generation, conducted a geological survey of1∶ 250,000 in Yushan County-guixi city area, established the stratigraphic system in this area for the first time, and made a preliminary study on magmatic rocks and volcanic rocks. Since 1954, geological teams belonging to geology, metallurgy, building materials system, scientific research, universities and other units have carried out systematic geological and mineral investigation and scientific research in this area.
During the period of 1954- 1959, Team 409 of the Central South Geological Bureau of the Ministry of Geology and Minerals conducted general survey and exploration in Dexing Copper Factory and Zhushahong, and found and proved Dexing super-large porphyry copper mine.
During the period of 1975- 1978, Jiangxi Geological Bureau organized Dexing Copper Mine General Meeting, adding 350× 104t of copper reserves, and systematically summarizing and studying porphyry copper deposits. 1983, Zhu Xun and others published the monograph Dexing Copper Mine.
During the period of 1959- 1980, Beijing Institute of Geology, Zhejiang survey team and Jiangxi survey team carried out the regional geological survey of Shangrao City Sheet1∶ 200,000, basically established the stratigraphic sequence, magmatic activity sequence and regional tectonic framework of the survey area, and accumulated rich basic geological data.
1976- 198 1 year, Jiangxi Hydrogeological Engineering Geology Brigade carried out a hydrogeological survey of Shangrao City Sheet1∶ 200,000, and preliminarily found out the hydrogeological, engineering geological conditions and groundwater resources in the working area.
During the period of 1983- 1988, the Geological Brigade of Northeast Jiangxi carried out a geological and mineral survey of1∶ 50,000 in Zihukou, Yushan and Gucheng, and studied the emplacement mechanism and formation age of Sanqingshan granite.
65438-0993, Jiangxi Urban and Rural Planning and Design Institute compiled the master plan of Sanqingshan Scenic Area. In 2000, the management committee of Sanqingshan invited the Institute of Landscape Science of Tongji University to revise the master plan of Sanqingshan Scenic Area. From June 5, 2003 to March 2004, Jiangxi Urban and Rural Planning and Design Institute revised the master plan of Sanqingshan Scenic Area again, which provided a scientific basis for the development and protection of Sanqingshan.
In 2000-2002, Jiangxi Geological Survey and Research Institute carried out a regional geological survey of1∶ 250,000 in Shangrao City. According to the evolution sequence of homologous magma, Sanqingshan granite is classified as Huaiyushan tectonic magmatic community, and a rock lineage unit system is established, which further improves the research level of Sanqingshan geological science.
1July 1985 to1August 1986, Jiangxi Geological Survey and Research Institute conducted a special tourism geological survey on Sanqingshan.
1999 ~ 2003, during the investigation of geological relics in Jiangxi province, Jiangxi Geological Survey and Research Institute conducted a general survey and evaluation of the granite peak forest landform in Sanqingshan.
From 2002 to 2004, scholars from Nanchang University and Jiangxi Normal University cooperated with Sanqingshan Management Committee to compile Sanqingshan annals, and systematically studied the historical materials of Sanqingshan from the fourth year of Taikang in the Western Jin Dynasty (namely, AD 283) to the first half of 2004, with a time span of 192 1 year. It highlights the research on tourism resources, physical geography and historical and cultural heritage.
From 2005 to 2006, the people's government of Jiangxi Province organized experts from different disciplines and hired geological science consultants at home and abroad to make an international comparative study on the scientific value of Sanqingshan natural heritage, focusing on biology and ecology. Lin Ying (1986), a famous ecologist, once pointed out that Jiangxi is an important origin center of China flora in East Asia-North America flora.
From 2005 to 2006, the Chinese Academy of Geological Sciences, Jiangxi Geological Survey and Research Institute and other units conducted a comprehensive investigation and preliminary study on the geological relic landscape of Sanqingshan Geopark, and put forward the concept of "Sanqingshan-style" granite landscape.
It should be said that the area where Sanqingshan is located has a high degree of geological research and many achievements (Chen Si Ben et al.,1986; Deng et al., 2005; Li et al., Li, 2000; Lu Songnian,1998; Ma Changxin,1991; Wang Yixian,1999; Xing et al.,1992; Xu Bei,1990; Xu Bei et al, 1989,1992; Zhao Jianxin et al.,1995; Zhao Chonghe et al.,1997; Ceng Yong et al., 2002; Zhou Guoqing, 199 1), to sum up, there are three most important achievements: the discovery of Dexing copper mine; Study on the scale, scope and genesis of deep fault zone in northeastern Jiangxi: the discovery of Mesoproterozoic ophiolite melange belt in northeastern Jiangxi. It can be seen that the research on northeast Jiangxi mainly focuses on Precambrian paleoorogenic belt and its structural framework, paleometamorphic rocks and their chronology, Proterozoic ophiolitic melange belt and its geological significance. Granite related to mineralization in northeast Jiangxi is also one of the research hotspots (Zhu Xun,1983; Yang Minggui et al., 2004; Jin et al., 2007; Rui Zongyao et al.,1984; Wang Qiang et al., 2007; Yuan Zhongxin, 1988). However, there are few scientific and quantitative studies on granite in Sanqingshan Scenic Area, and most of the related documents are the introduction of geological tourism resources in Sanqingshan or the description of granite landscape (Liu Xiyuan et al., 2005, 2006; Yang Minggui et al., 2007). Sanqingshan Mountain is a natural museum of granite micro-landforms, which records the crustal evolution history since Mesozoic. Traditionally, the mechanism of mountain formation and landscape formation is explained by the fact that the crust is constantly uplifted by internal forces, and external forces are constantly weathered and denuded along joints and cracks, creating various vivid micro-landscapes. But what does it have to do with granite itself as a material basis? On the premise that the lithospheric thinning in eastern China is recognized as scientific knowledge, what is the relationship between the formation of many granite mountains in eastern China and the lithospheric thinning in eastern China? Is it formed in an extrusion environment or a tensile environment? What are the characteristics of the uplift and erosion process of Sanqingshan Mountain? Does Sanqingshan Mountain have the same uplift and erosion process compared with Huangshan Mountain, which is located in the same orogenic belt with the same rock type and landform type?
Mr. Chen Anze once pointed out that granite experts do not study granite landforms, while geomorphologists know little about granite petrology and cannot explain the relationship between granite landforms and geology. It is not advisable to divide the geological landscape into two skins. Geomorphologists should understand the basic knowledge and frontier research fields of geology, and researchers of geoparks should also understand that geoparks are only the carrier of research, and the research contents can be petrology, geomorphology, geochemistry, geophysics and tectonics. Granite landform is an important evidence to study the geological evolution process (Chen Anze, 2007), because landform contains the relevant information of environmental changes in the past geological history, which is helpful to understand the history of environmental changes of the earth, and more importantly, it can provide scientific basis for predicting the direction and trend of future changes (Li Qiong, 2008). Markov (1948), a geomorphologist in the former Soviet Union, studied the magmatic movement in the process of geomorphology. At the First International Symposium on Granite Geology and Geomorphology (Geological Review, Volume 53, Supplement), there were papers published by Hong David, Xiao Qinghui, Luo and other lithologists, which was a good start and contributed to the discussion and exchange between geomorphologists and lithologists. But generally speaking, granite landforms have not been paid due attention to in the study of geological evolution history. Based on this consideration, this monograph will study the rock geochemistry of Sanqingshan, the low-temperature geochronology constraints of Sanqingshan uplift and erosion, the geomorphological characteristics and genetic mechanism of Sanqingshan.