The Development Of Motive Paleogeographic Reconstruction Modeling System

This dissertation firstly sets up a comprehensive database which serves for paleocontinental and paleogeographic reconstruction, and accomplished a system of motive paleogeographic reconstruction. Based on all sorts of geology data and taking the theory and method on motive global tectonics as the guidance, the modules of paleocontinental reconstruction is developed by terms of the Euler’s theory and mathmatic fomulus. Futhermore, the results of paleocontinental and paleogeographic reconstruction are integrated closely together. Thereby, the evidence can be provided for studying petroleum accumulation and distribution for petrogeologist from the aspect on mobilistic tectono-paleogeography. The major results and innovation of this dissertation is as follows.1. developing the modules of paleocontinental reconstructionUtilizing the ArcObjects components and the functionalities of data management and visualization in ArcGIS, this dissertation developed the functionalities of paleocontinenal reconstruction including euler rotation, which can be embedded in ArcGIS. Because the existing functionalities of ArcGIS are employed in development, the time of development is shorted and the process of data convertion is reduced. Moreover, the function of ArcGIS is extended, the developed function can be loaded to ArcGIS conveniently and there is more flexible. These functionalities provide a technological support for paleocontinental reconstruction. At the same time, the developed functionalities are universal and can also be applied to paleocontinental reconstruction in other regions,3. Proposing a technology route served for paleocontinental and paleogeographic reconstructionAfter studying the existing results thothoughly, a technology route and workflow served for paleocontinental and paleogeographic reconstruction is put forward. In the light of the workflow, the maps of paleoterranes’position on the interval of ten-million-year are accomplished. And also, the motion evolution of paleoterranes is showed. Addtionally, the three-dimention shading maps of paleo-height including paleotopography and paleobathymetry are fulfilled. The approach utilizes the advantage and tools of ArcGIS software and integrates the developed functionalities into the paleogeographic reconstruction closely. Therefore, employing the computer and GIS technology, it is easier for paleogeography reconstruction. And the workflow provides the approach for the information technology development of our country on paleogeographic reconstruction.4. Accomplishing paleocontinental reconstruction based on GIS technologyEmploying the developed functionalities of paleocontinental reconstruction and spatial presentation tools of ArcGIS, the terranes’past position maps in Tethys region in Tibet are drawn according to all sorts of data including paleocontinental reconstruction maps based on geology data, paleomagnetic data and the existing geology results. In addition, utilizing the research results of American Prof. Scotese etc in the Chicago university, the terranes’past position of the neighbor regions in Tibet are vectorized. Consequently, the terranes’motion evolution with the time in Tethys region in Tibet is modeled dynamically, and also the open and closure of the Tethys Ocean and the terranes evolution in the region are showed.5. Accomplishing paleoterrain recovery (paleoheight) based on GIS technologyCombining paleoterrain recovery technology with spatial interpolation method and three-dimension visualization of ArcGIS, the paleodigital elevation models are completed based on the lithological paleogeographical maps. Then, the models are shaded from three-dimension and the paleotopographic maps are generated. Also, the three-dimension paleogeographic maps with paleotopography are agreement with paleogeographic sedimentary distribution. The results show that this approach can better represent the relief features indicated by sedimentary facies of paleogeographic maps.6. Constructing the motive paleogeographic reconstruction databaseAccording to the principle of paleogeographic reconstruction, the motive paleogeographic reconstruction database of Tethys region are designed on the basis of the spatial database-Geodatabase in ArcGIS, which includes paleomagnetic data and the terrane graph features etc. The database provides a data support for the plate motion modeling subsystem. Futhermore, with data management function in ArcGIS, the terrane features are closely connected with the geology data. And also, it is easy for geologist to model the plate position iteratively with the computer directly. Moreover, it is more convenient to check and correct the errors during modeling the plate motion.