Morphostructure of the territory of the Republic of Burundi

Abstract

Introduction: the scientific problem in studying the morphostructure of the territory of the Republic of Burundi is to clarify its relationship with the tectonic structure of the foundation. The purpose of the article is to highlight the main elements of the morphostructure and evaluate their role in reflecting the structure of the foundation.

Methodology: the study site is located within the western branch of the East African Rift System, east of Lake. Tanganyika. The sequence of the study included a description of the main subdivisions of the territory's relief, an analysis of the geological structure of the Precambrian foundation (section and lithology of rocks, as well as the identification of structural levels, the study of their relationship with each other and a description of the main features of the internal structure). The next stage involved studying the morphostructure of the territory, identifying its lithomorphic and neotectonic components. Based on visual interpretation of satellite images, lineaments and ring morphostructures were identified. During decryption, a planned drawing of the hydraulic network was used as a decryption feature. For ring morphostructures, using the dependence of their sizes on the depth of location of the initiating foci, a schematic map of the surface of the initiating foci was compiled. At the last stage, the results of morphostructural analysis were compared with the geology of the basement. The materials used in the work were geological survey data of the territory, satellite images, a digital elevation model, as well as published materials.

Results and discussion: as a result of the research, the relief of the territory was characterized, which includes (from west to east): the low-lying area of ​​Imbo along the eastern shore of lake. Tanganyika, the Congo-Nile ridge, the Central Plateau, a strip of relatively low areas on the border with Tanzania - Buragan, Kumoso, Buyogama. An analysis of the geological structure of the territory of the Republic of Burundi was carried out. The section of rocks composing the Precambrian basement includes formations of the Upper, Middle and Lower Proterozoic – Archean. Of great importance are the quartzite layers, which play the role of armoring horizons. The western and northwestern parts of the territory are saturated with granitoids, which determine the hilly nature of the relief. Tectonically, based on the presence of unconformities, the territory can be divided into three structural levels, differing in their internal structure. In the morphostructure of the territory, two types are distinguished: lithomorphic and neotectonic. Lithomorphic elements are clearly recognizable on the digital elevation model. When interpreting satellite images, some of the identified regional lineaments coincide with the marking layers. The neotectonic component of the morphostructure is formed by the eastern side of the lake rift. Tanganyika. The Congo-Nile ridge represents a fragment of a shoulder of a rift structure. The Central Plateau and adjacent low areas are fragments of the African Plate.

Conclusion: as a result of the research, the following conclusions can be drawn: the features of the morphostructure exhibit both lithomorphic and neotectonic components. The lithomorphic component clearly shows the structure of the Proterozoic. The field of lineaments reflects faults in the basement only in fragments and is apparently associated with neotectonic ruptures. An important place in the morphostructure is occupied by ring elements. the depth of the sources that initiate them may correspond to the depth of the earthquake hypocenters and, possibly, to the position of the base of the earth’s crust. This conclusion deserves special attention from a methodological point of view and requires additional research.