The Application Of 3D Visualization Technology In Digital Geological Mapping

Due to the complexity and diversity of geological information during geological survey,some geological phenomena which are actually in form of three-dimensional space cannot be accurately expressed through two-dimensional maps.To rationally analyze and explain the geological problems,it is urgent to use three-dimensional geological modeling software to simulate and visualize the geologic bodies.Predecessors have done a lot of research in Hetao plain,but almost all of them were based on the traditional two-dimensional way of field geological survey,there is a lack of 3D special analysis in the study area.Therefore,this paper mainly adopted the method of borehole exposure,using1-5m groove drill and 1-15 m percussion drill,with the aid of furtherly remote sensing interpretation and geological radar detection,to carry out geological research on the basis of comprehensive reconnaissance.As a result,a lot of drilling data and other related materials have been collected.After the indoor data processing,I adopted the DSI interpolation algorithm and triangulation algorithm,mainly use the method of “object box” to construct the 3D geological model.Through the gradual construction of the model,this study mainly completes the following results:(1)During the field geological survey,we collected all kinds of borehole core data systematically,and determined the formation and distribution of lithology characteristics of quaternary sediments in the study area.In addition,the multi-source data and geological maps were digitized,vectorized and integrated,the problematic data was modified,and the modeling basic database was organized.(2)Using the GOCAD operating platform,I resampled and densified the data.Adopting the DSI interpolation,I mainly used the method of “object box” to construct 3D model.As a result,I completed three 3-D granularity attribute models at the scale of 1:50000.And I furtherly processed,and then finished the establishment of a three-dimensional stratigraphic structure model at the scale of 1:25000.The model reflects the distribution of fine sand and clay layers,which are instructive to theselection of land use in farming areas,the judgement of underground aquifers,and the analysis of engineering geological conditions.(3)According to the sedimentary assemblage characteristics,we determined the division standard of sedimentary facies in the studied area.In accordance with the characteristics of granularity attribute model and field core sediments observation,I discussed the sedimentary characteristics of each map.And with reference to the two-dimensional route geological mapping results,we identified the ancient Yellow River staging,and then taking advantage of the three-dimensional sedimentary profile to build the 3D expression of the ancient Yellow River channel evolution process.We concluded that there are 4 ancient channels in our study area: In Hulesitai brazilwood,there are two stages of river channel,they are the phase ? and the phase ?.Taer lake buried the phase ? paleochannel.In Fuxing town,besides the modern Yellow River,there are two phases of the Yellow River paleochannel—Phase ? and phase ?.Our research are closely corresponding to the results of remote sensing interpretation and geological mapping.This paper summarized the technical methods and basic processes of establishing the three-dimensional granularity attribute model and the 3-D stratigraphic structure model in the process of digital geological mapping.And it provides a good reference to deeper geological survey and 3-D modeling.