Research On Geological Landscape Classification And Genesis Of Mid-western Section Of Daba Mountains

Located in the north-south boundary zone of China,Daba Mountains is at the southern foot of the Tsinling-Daba Mountains' orogenic belt and northern edge of the Yangtze platform,and the transitional edge of the Sichuan Basin and the Tsinling Mountains' orogenic belt.The arc-shaped tectonic belt of Daba Mountains is a typical example of the fold mountain system in China.In the meantime,Daba Mountains is a natural place for the studies of geography-climate-animal and plant differentiation between north and south areas of China,intracontinental orogenic movement,and the Karst geological landscape in the transitional zone between the north and the south.Thanks to the unique geographical location and geological structure of Daba Mountains,this region boasts rich geological landscape resources.The mid-western section of Daba Mountains has a subtropical continental montane monsoon climate,and due to the joint influence of geological structures,crustal movements,and climate and hydrology,Daba Mountains presents rich geomorphologic types and diverse geological landscapes,and the natural tourism resources here are abundant as well.However,the regional economic development of Daba Mountains lags behind.The gross domestic product(GDP)per capita of the region in the study area is only 2/5 of whole country,which belongs to the less developed area.It is part of the concentrated area with special difficulty of TsinlingDaba Mountains in China,and it belongs to the 14 concentrated poverty aleviation development zones in China;the urbanization rate of the region of the study ares is far lower than that of Sichuan Province,Chongqing Municipality,Shanxi Province,Hubei Province,Gansu Province,and even the national average level of development.Sharp contrast can be observed between its rich geographical landscape resources and backward economic development.Therefore,the starting point of this study is to find ways to rationally develop and scientifically protect the rich geological landscape resources in the mid-western section of Daba Mountains so as to promote the sustainable development of the local economy,society and ecological environment.Based on theories in such fields as geology,geomorphology,ecology,geography,geographic information technology,statistics,and taxology,this article discusses classification,controlling factor analysis,causes analysis of formation and characteristic analysis of geological landscapes in the mid-western section of Daba Mountains,explores the development direction and protection strategies of the midwestern section of Daba Mountains' unique geological landscape resources.This study is also the application and practice of Quaternary geology in the direction of geological landscape research.The rich geological landscape resources in the study area are closely related to the thrust fold belt of the mid-western section of Daba Mountains and the tectonic setting of the northeastern Sichuan Foreland basin.The regional tectonic conditions have laid a solid material foundation and geotectonic environment for the formation of the geological landscapes of the study area.The following results have been achieved through the study:(1)The rich geological landscape characteristics of the study area are closely related to its location in the thrust nappe tectonic belt,the Daba Mountains' thrust fold belt and the tectonic setting of the northeastern Sichuan Foreland basin.The geological structure in the mid-western section of Daba Mountains has generally undergone the transformation from marine sedimentation caused by Indosinian movement in Late Paleozoic to Early Mesozoic to inland lacustrine sedimentation,the paleocontinental platform uplift-thrust nappe-tectonic detachment deformation resulted from Tsinling Mountains' orogeny in the late of Middle Triassic,and the intracontinental orogenic uplift in the regions of Qilian-Qinling Mountains from the Middle Jurassic to the Early Cretaceous,resulting in the formation of successive head-to-tail “Daba Mountains arcuate structures” in the plane,and the continuous oblique uplift of the study area caused by Himalayan orogeny in the Late Eocene Epoch.Under the background of neotectonic movement,the unique NW-SE parallel distribution of middle Daba Mountains and the nearly EW trending fold mountains,faults,hills and intervalley basins in Western Daba Mountains were formed.In the middle of Daba Mountains,the northern massif spreads from the north,west to the south and finally to the east(NW-SE),and the southern one shows an arc-shaped distribution protruding from the south to the east;in the west of Daba Mountains,the massif presents nearly a east-west(EW)distribution.These distribution laws are consistent with the regional structural traces,showing that they have a genetic relationship.Under the action of superimposed external dynamic conditions such as flowing water,biology,wind and climate,abundant flowing water landforms and karst landforms have been formed.Under the superposition of external dynamic conditions such as running water,biology,wind power and climate,the rich fluvial geomorphology landscapes and karst landscapes in Daba Mountains have been formed.(2)The geological landscape in the middle and western Daba Mountains can be divided into four landscape systems: the Daba Mountains arc structure landscape system,the Micangshan-Hannan basement fold uplift landscape system,the northern Sichuan foreland hill landscape system and the Hanjiang River flow aluvial fault basin landscape system.The geological landscapes of the mid-western section of Daba Mountains can be classified at three levels:two major categories,three subclasses and five geological landscape types.In the primary classification,the geological landscapes of the study area are divided into geological landscape broad heading(I),dominated by endodynamomorphic geologic function,and ectodynamomorphic geologic function(II);In the secondary subclasses,the main types of geological landscape dominated by endodynamomorphic geologic function include: subcategory(I-1)of crustal movement landscape,the main geological landscapes dominated by ectodynamomorphic geologic function are landscapes of climate and water flow(II-2),and the landscapes(?-3)of paleontological sedimentation.In the third-level classification,the geological landscapes of the mid-western section of Daba Mountains is subdivided into five types of geological landscape: geological structural feature,geological section landscape,geomorphologic landscape,fluvial geomorphology landscape and paleontological landscape.From the aspects of controlling factors and function process of geological landscapes in the study area,the typical representatives of 5 types of geological landscapes in the study area are analyzed in detail.(3)The geological landscapes of the mid-western section of Daba Mountains have high ornamental value,scientific research value and development value.There are 101 major geological landscapes evaluated in the mid-western section of Daba Mountains: 5 five-level landscape areas,13 four-level landscape areas,8 third-level landscape areas,35 second-level landscape areas,and 40 first-level landscape areas.The geological structure landscape is the guiding landscape tourism resource in the study area,of which five geological landscape areas,Daba Mountains Geopark,Daba Mountains Natural Reserve,Hua'e Mountains Natural Reserve,Nuoshui River Scenic Area and Guangwu Mountain Scenic Area,have international influence.(4)Promote the sustainable development of regional tourism on the basis of geological landscape resources.Give full play to the scientific research experience,health care and leisure,green health,and ecological tourism advantages of the study area,and this can be achieved by the mode of ecological priority,coordinated development,"Travel & Science and Technology",three-dimensional development and multi-point multi-polar development to assist the research area in poverty aleviation and regional socio-economic-environment coordinated development.(5)The strategy is that the construction of "Daba Mountains National Park" should be declared to protect the geological landscape resources in the mid-western section of Daba Mountains.It is also suggested that delineate the functional division of “Daba Mountains National Park”reasonably,establish a community co-management mechanism,improve the ecological protection compensation system,improve the community participation mechanism,and effectively promote the protection of geological landscape resources in the study area.