The Research Of Method Of Geochemical Element Spatial Quantitative Association And Visualization

Stream sediment geochemical prospecting the ore is that using stream sediment geochemical survey to find out the concentration and dispersion regulation of chemical elements in stream sediments, then discover the geochemical anomalies in stream sediments, in order to determine the dispersion train of the ore deposit and specify direction of orebody; But more is the using of stream sediment geochemical anomalies to delineation the mineralization potential.Dissertation depends on the measured 1:200,000 stream sediment geochemical survey in Hebei shanghuangqi and 1 : 200,000 topography map. Geochemical anomalies are identified by the method of factors - universal kriging, and using this method to implement the spatial quantitative association anomaly of element; Relying on sources data of topography map, the digital elevation model (DEM) have been found; Through the hydrological analysis on digital elevation model, the catchment basins and water network maps are extracted. Then combine the metallogenic geological conditions and the map of catchment basins water network to make the metallogenic prognosis for the dispersion of the orebody which determined by the anomaly. The aim is to establish a theoretical model about the spatial visualization method of earth geochemistry element, and make application.Geochemical data processing has two purposes: First, to determine the regularity of elements symbiotic association; Second, to separate geochemical background and geochemical anomalies. The dissertation uses factor analysis of multivariate statistical analysis to study the paragenetic association regularity of element. Factor analysis has the function of compressiing variable space and reproducing inner correlations of primitive variables. Using the techniques that factor comes from the linear association and the rotation transformation of original variables we can convert multi-element variables collection which in geochemical data matrix into a few index of elemental quantitative composition which has a specific significance of instructions the orebody. There are 1,413 samples and 24 geochemical elements variables in the study area, they are: MgO, Na2O, Fe2O3, K2O, Mn, P, Cr, Pb, Zn, Sr, Ba, Ag, Cd, W, Mo, As, Sb, Bi, Hg, Sn, Al2O3, Co, Cu, Au. Through conversion of R-variance factor orthogonal rotation greatly those samples simplified into six main factors. High load variables in F1 are: Fe2O3, Co, Mg, P, Cu, Cr, Ba, Sr; High load variables in F2 are: As, Mo, Sb; High load variables in F3 are: Cd, Pb, Zn, Ag, Mn; High load variables in F4 are: As, Al2O3. High load variables are not obvious in F5 and F6. So they will not be discussed in this dissertation.At the basis of variance factor orthogonal rotation greatly solution, we can find out anomaly from the new lattice which rely on the original grid data. The process followed the correlation and designability of spatial data and multivariant of raspatial objects. In the process of search for anomaly, the lattice of the above data can be understand into Z(x) of drift regions variable, so Z ( x ) = m ( x ) + R ( x),then, through the seeking of mathematical expectation m(x) can obtain R(x) which is a anomaly region. of course, it is assumed that Z (x) has variability function, its theoretical model is the spherical model, and increment with first moments and second moment, solving kriging equations without bias and under optimal conditions we can get m(x). Abnormal Results express by contours, according spacing of contours and scope of the abnormal, the study area were ringed 11 parts. Direction of abnormal distribution was roughly NE-SW, the same as the direction of main tectonic line in the region.Through data sources of 1:200,000 topographic map and method of irregular triangular network modeling, the DEM of the study area has been found in ArcGIS, stacking remote sensing images and geological grid map in the ENVI, implement the 3D visualization of topographical features and the distribution of geologic body in the study area, then professional information is visual expressed and the natural landscape features are simulated, which are shared, collaborative and distributed. 3D visualization of anomaly about elements of quantitative association in space is more concise visual showed the direction of anomaly in space and distribution in space of the scope and morphology.The extraction of the hydrological characteristics in stream area is depending on data sources of the digital elevation model (DEM). The United States Environmental Systems Research Institute (ESRI) provided a hydrological analysis model (Hydrology Model) for ArcGIS, mainly for the extraction and analysis about terrain and river networks in order to implement terrain model visualization.The study area is subordinate to the axis of Inner Mongolia in construction, north latitude reached 42°, at the northern edge of china- North Korea Yanshan structural layer and cenozoic cover and strong tectonic movement which made fracture is the mainly tectonic and sub-fold is secondary, and the direction of this tectonic is more obvious with the mainly direction of north east- south west. Late Jurassic magmatic is activity in the region, the activities kinds are volcano eruption and magma intrusion, resulting in a series of volcanic and intrusive rocks. The region basement, Jurassic basin, magmatic activity and faults controlled polymetallic mineralization.Tracing the source of anomaly with anomaly precondition of elements in space quantitative association in study area and the combination geological background of mineralization the of mineralization with river network in stream basin,a total of 9 polymetallic mineralization districts were ringed , the main ore-forming elements are: Fe, Co,Cu, Cr,Cd,Pb,Zn, Ag,As, Sb, Mo.The information on existing research and analysis shows that the area has more potential for exploration. Suggesting that start 1:50000 regional geochemical survey in the abnormal area, meanwhile with geophysical exploration. The gravitation and magnetic prospecting can help interpret the old basement and deep faults and identify geological body which causes the anomaly, to provide evidence for searching minerals.