The Metallogenic Types Characteristics And Prospecting Indicator Of The Molybdenite In Dawan, Lai Yuan County,Hebei

This article relies on two projects, one is Chinese geological survey project,"Mesozoicmagmatism and mineralization in the Taihang mountains "(project Numbers:1212011121076);The other is National Natural Science Fund project, the spatio-temporal evolution ofMesozoic magmatism and mineralization in the Taihang mountains(project number:4104002).According to the field observation,combined with rock slice microscopy indoor,compared with the alteration characteristics of typical porphyry-type ore deposits, this articledid some Re-Os analysis of the molybdenite,and determined the age of molybdenitemineralization; Through the analysis,such as major elements and trace elements, sulfurisotope, lead isotope, and hydrogen and oxygen isotope, the article determined the source ofore-forming materials of three types are the same or different; Via systematic sampling andanalysising on alteration zone in which the geological character changes more obvious, thisarticle determine whether there is a regularity or not; The article want to verify whether theore-rock is rhyolite porphyry or not, establish the relationship between mineralization andmagmatism,and set up the metallogenic model, point out the prospecting indicators and mainore-prospective areas.Through the above research, this article came to the following conclusion:（1）This paper puts forward a new classification method, according to the metallogenictypes: porphyry type molybdenum body, skarn type molybdenum body, hydrothermal veintype molybdenum body; According to ore-hosting rock types: porphyry type molybdenum,skarn type molybdenum and gneiss type molybdenum and a little quartz vein type.（2）The ore-forming material,which mainly derived from the upper mantle and lowercrust, is a melt-granite, in part from the surrounding rock. The Rb-Sr age of rhyolite porphyryis139.7Ma (the predecessor’view,142.8Ma), which is basically the same as volcanic rocks inEast Ridge (140Ma), and has the characteristics of volcanic rock; The mode Re-Os age ofmolybdenite is137Ma.It further determines the conclusion that the ore-rock are rhyoliteporphyry.（3）Division of metallogenic series: Dawan deposit producted in Xing’an-South ofTaihang metallogenic belt, it is relates to crust-mantle mixed source relating tointermediate-acid intrusive rock in Yanshanian, it can further relate to the secondary depositsseries of volcanic-subvolcanic.（4）Prospecting indicators:The lower and buffering of magnetic anomaly and induced polarization anomaly can be used as the basic geophysical prospecting signs; primary haloanomaly and main ore-forming elements enhanced field and reduced field can be used as thegeochemical symbol; ring structures which is in Remote sensing image, can be used as aindirect prospecting marks, especially the intersection between ring structures and linearstructure can make for mineralization. In addition, the tectonic symbol, times, strata signs,porphyry marks, wall-rock alteration sign can be used as direct prospecting marks.（5）There are three ore-prospective within the mining area: intergrowth silver depositvision sections, molybdenum vision section, and skarn iron ore prospect section.There are two ore-prospective the mining external area: FuTu valley-WangAn town andDongTuan fort-YeGu.The former is favorable zones to looking for the hidden ore aboutsubvolcanic rock, and it can be used as a key analysis research.The latter, especially Antuoling, Yegu and Lianbaling, is favorable zones to looking forPorphyry deposit, and it can evaluate porphyry of subvolcanic rocks, and it can evaluate theore potential in shallow porphyry in later period.