3D Spatial Distribution Rules Of BIF In Anshan-benxi Area

With the increasing demand of the resources of the deposit and thedecreasing amount of the exploitable mineral resources in surface and shallow,prospecting patterns have been changed from the exploration anddevelopment of mineral resources in the shallow to geological prospecting inthe deep. Finding out the total of mineral resources and the rules of spatialdistribution, can not only to provide basic information on geology and mineralresources of our country, but also provide guidance and reference in majorstrategic decisions.Anshan-Benxi area, which is China’s Archean “Anshan Type” BIF(bandediron formation) Metallogenic region, has found a number of very large iron oredeposits. Since BIF has been founded, many domestic and foreign experts ofgeological has carried out a lot of depth research in different aspects, andmade a lot of important research results. But there are still many problems tobe solved. Many Chinese experts have been researched the iron’sconstruction characteristics, causes model, age, evolution and distribution indetail in Anshan-Benxi as well. They have been proposed many differenttheories and konwledge, and have many different views on the spatialdistribution of Iron formation in Anshan-Benxi. While predecessors have donea lot of work on BIF, but not yet adopted a method of3D geological modeling,which study the spatial distribution of iron formation from the perspective of3D. In early2012,"Deep Geological Survey and the3D geological mapping"experimental project marked the3D geological modeling has entered a periodof rapid development. Expression of geological information is also developedfrom traditional forms such as plans and sections into a3D space. Therefore, itis an inevitable trend to research the rules of3D spatial distribution of Ironformation in Anshan-Benxi and establish3D spatial distribution model.Predecessors have done a lot of research work on BIF, which mainlyfocused on the causes, the material source, mineralization time, the times ofdeformation, the history of evolution. They had made a lot of achievements,but got no uniform conclusion. Since the mineralization age of BIF is old, thelate alteration is complex, so its original form and the transformation process isquite difficult to recover. This paper based on predecessors’ studies, conducted geological data acquisition, mining area information summarizing,geophysical inversion and a series of work, used the methods of undergroundgeological inference, integrated geophysical inversion, geochemical analysis,3D modeling methods comprehensively, studied3D spatial distribution rules ofBIF in Anshan-Benxi area in detail. The main knowledge and results achievedare as follows:(1) Summarized rules of BIF, spatial distribution rules of iron ore body,spatial distribution rules of hematite, enrichment rules of rich iron ore andproposed folds and ductile shear are the significant factors of iron ore becomerich.(2) Summarized three modeling methods to build spatial distribution ofiron formation.①The3D geological modeling method based on the geologicalcross-section;②The method of Block-divided geologic modeling;③Thegeological modeling method of geophysical comprehensive constraint.(3) Summarized hook-like, board-like, ingot-like three kinds of3Dgeometry models of iron formation.(4) Determined the occurrence space of BIF.①Core of the syncline;②Covering by cap rock;③Smaller tectonic uplift, buried deep in the area.(5) Cleared tectonic, magmatic intrusion, weathering and erosion thosefactors effect the spatial distribution of BIF.(6) Summarized three development patterns of concealed orebodies.①Overthrust type;②Syncline cover type;③Cenozoic cover type.