Geography is a science that studies the relationship between man and earth. Geology represents "man land", which is "half the sky", which plays a very important role in geography. The field practice teaching of geography includes two parts: Human Geography and physical geography. Geological knowledge is not only closely related to the practical teaching of human geography, but also plays an important role in the practical teaching of physical geography. Taking the field practice teaching of physical geography as an example, this paper makes a preliminary analysis. For one's own words, please criticize and correct.

The author believes that geological knowledge includes three parts: crustal material composition, geological structure and geodynamics. Geology itself is a highly theoretical and practical science. The greatest feature of physical geography is to highlight the study of epigenetic processes and their relationship with human activities. How to closely link the two is a problem worthy of serious exploration and thinking in the teaching process. Because if we don't find the combination of the two, the teaching of geological knowledge may deviate from the track, or make the practical teaching of physical geography evolve into the practical teaching of geology, or become popular in the "sightseeing" tourism because it is separated from the support of geological knowledge. Therefore, the author emphasizes the following three points.

1. Geological knowledge is the knowledge basis for understanding natural geographical phenomena in the field. The field natural geographical phenomena include both macro scale and local typical natural geographical phenomena. The macro scale involves regional spatial changes, such as the development of landform, the formation of soil, the transportation and accumulation of sediments, the formation of sand and dust (there are four dust source areas providing atmospheric dust particles on the earth), the role of water, etc., which are inseparable from the analysis of geological knowledge such as rock and structure. Even the atmospheric circulation is related to geological knowledge. For example, the concept of "Anthropocene" is a scientific understanding obtained by computer simulation based on the oxygen isotope analysis results of dust particles over the Sahara desert in North Africa and the tropical rain forest in South America. Therefore, geological knowledge penetrates into all aspects of physical geography and is the knowledge basis for understanding physical geographical phenomena.

In the analysis of various natural geographical phenomena, rock weathering is its core. Weathering is closely related to geomorphic type characteristics, soil development, vegetation distribution, ion composition of flowing water, etc. Therefore, the author believes that various forms of physical geography field practice should pay special attention to the understanding and analysis of weathering. The weathering of rock involves the observation and analysis of many specific phenomena, such as the type, degree, products of weathering and its relationship with soil development. These phenomena are often closely related to the knowledge of rock type, mineral composition, geological structure and so on.

Different from geology, various natural geographical phenomena developed on the surface are not only related to internal dynamic geological processes, but also controlled by various external dynamic geological processes. For example, the same karst landform, Jiuzhaigou, Huangguoshu and Guilin show different geomorphic characteristics. From the perspective of geology, this is caused by different crustal movements under different tectonic backgrounds; It is also the result of various factors such as surface CO2 concentration, temperature and air pressure.

Therefore, the author believes that the national joint field practice teaching of geography should pay special attention to the application of geological knowledge in the field practice teaching of physical geography.

2. Geology provides the basic method of field work for physical geography. As an important branch of geography, physical geography has strong comprehensiveness, practical exploration and its own unique working methods. For example, observation, description and recording of field phenomena. To a certain extent, the field work methods of physical geography and geology are interlinked. But the field work method of geology has more professional characteristics. Since the lithosphere part of physical geography is the embodiment of geological expertise in a general sense, the author believes that geology provides the basic method of field work for physical geography. For example, geological working methods such as lithology description, occurrence measurement and rock stratum thickness measurement are applicable in physical geography, and they are also the basic working methods in the field of physical geography. However, it is found that many students majoring in geography do not measure the occurrence of rocks. To study the landform, understand the distribution of river gravel, and even explore the structural characteristics of soil profile, we need to grasp the characteristics of rock occurrence. This requires us to master the basic field work methods. The observation and analysis of lithology and typical structures in geology provide basic working methods for the field practice of physical geography.

3. Geological knowledge provides professional training for field practice teaching of physical geography. From the perspective of scientific research, physical geography and geology have many ideas or the same working methods. That is, we need to observe, describe, express and analyze the field physical and geographical phenomena, and then carry out scientific processing and logical thinking analysis. Judging from many master's and doctoral dissertations reviewed in recent years, this basic work link is a weak link for many graduate students majoring in physical geography. That is, there is a lack of basic skills in the observation, description and expression of the research object, and the description and expression of field data, that is, the scientific analysis and expression of the first-hand field data obtained by yourself, is the basic work of forming scientific research materials and supporting materials for scientific analysis, and the embodiment of the basic skills of field work of geography specialty. However, I feel that some graduate students' training in this field is obviously insufficient.

Like the study of geology, the study of physical geography emphasizes the grasp of field first-hand data and materials, because field first-hand data and materials are the basis for our original innovation. Therefore, it is hereby suggested that the national field geography joint practice teaching should especially strengthen the training and grasp of students' basic skills in this aspect. To achieve this goal, we need to closely combine the design and layout of field practice teaching of geological knowledge associated with physical geography.