Geological Characteristics And Prospecting Direction Of The Sujia Fe-Zn Deposit,Heilongjiang Province

Sujia Fe-Zn Deposit is located in Bindong area,Heilongjiang province,theimportant metallogenic belt of hydrothermal deposits and skarn deposits, tectonicallyin border of east edge of Xiao Xing’an range-Songnen block and west edge ofYichun-Yanshou geosynclinal fold system, belongs to Xiao Xing’an range-Zhangguangcai range metallogenic belt. The natural geographical condition in studyarea is superior, labor resources is sufficient, transportation is convenient, water andelectricity is supply, provides a favorable condition for the mineral development.The metallogenic rock body is Yizuomao rock body,it is composed of gabbros-diorites,granodiorites and Porphyrys,etc.of Yanshan epoch;Various ages stratas of Palaeozoic-Cenozoic has a inordinately esposed, which close to Sujia Fe-Zn deposit are mainlyrhyolitic porphyry,sandstone of Yuquan group,upper carboniferous and slate,sand-slate of Pingshan group,lower Permian;Bindong area is divided into two parts ofNW and SE by Yishu fault, fault and fold structure development, structure linedirection are mainly NE and NNW.Ore bodies are mainly skarn Fe, skarn Fe-Zn and skarn Mo ore bodies,occurrence in the skarn zone, sedimentary rock fracture zone which is nearby theoutside contact zone of syenogranite and interlayer rupture belt of marble. Themorphology of ore bodies are mainly vein, lenticular, layered and stratiform-like,more of them occurrence above50m elevation, controlled by the NW construre,hasa certain mineralization zoning.The main metallic minerals of Sujia Fe-Zn deposit includes magnetite and sphalerite, and associated with galena, chalcopyrite, bornite, molybdenite andpyrrhotite and so on; Nonmetallic minerals are mainly andradite,grossular anddiopside,and with wollastonite,tremolite,actinolite,epidote,sericite,quartz,chlorite andcalcite etc. The ore texture commonly are grain texture,erosion metasomatic texture,exsolution texture and poikilitic texture etc.;The ore structure mainly includes massiveand disseminated structures,with lccal veinlet,filling and spotted structure.Ore typesare mainly magnetite,sphalerite,and then molybdenite, galena, associated with copperore.The main types of the wall rock alteration include skarn,petrified, sericitization,quartzitification,horfels,carbonation and chloritization etc.Generally,it is mainly skarnand petrified when the wall rock is marble; silicification and sericitization are oftenappeared in the marble of orebody edge accompanied by other alterations;it is oftenskarn, horfels, chloritization and carbonation when the wall rock is slate;it showsskarn, horfels and chloritization while the wall rock is granite aplite;the tuffaceoussandstone near the ore bodies is often horfels,and carbonatite becomes intomarmarization,above all wall rock alteration commonly begin with skarn and end withcarbonatation.Ore bodies are mainly pyritization and chalcopyrite.Analysis of major elements shows that marble has a different degree ofsilicification,reflects its features that metasomated by siliceous fluid (magmatichydrothermal);correlation coefficient between the ore-forming elements and differentelement groups show the close relationship between the main mineral elements andindicator elements, provides an important clue for prospecting;The Nb/Ta of graniteporphyry in the area shows that the magma comes from the crust,the Rb/Sr and Zr/Hfof ore show that the metallogenic material of Sujia Fe-Zn deposit is also comes fromcrust;each ore samples have obvious Eu negative anomaly,the distribution of rareearth elements are consistent, on behalf of they have common source and similarformation mechanism.Through summarizing predecessors’ research results,the age of metallogenic rockrelated to Sujia Fe-Zn deposit concentrated in175~200Ma, further researchcompared with other deposits surrounding,we conjecture that the metallogenic rock of Sujia Fe-Zn deposit probably formed in lower Jurassic.Tectonic movement ofZhangguangcai range brought rich ore-forming materials for the study area, such asFe and Mo, the characteristics of trace elements and REE of rock and ore all show thatore-forming material comes from crust. Magma evolution and metasomatism withsurrounding rock during the process of its rise makes the ore-forming materials likeFe,Zn enriched in the fracture zone between the marble, formed skarn ore bodies andmineralized bodies.According to the geological characteristics, geochemical characteristics and thestudy of the surrounding deposits with the same geological background and similarlyfactor, determine the Sujia Fe-Zn deposit is a typical skarn deposit. Sujia Fe-Zndeposit metallogenic geologic condition is superior,Yanshanian syenogranite,granodiorite and granite porphyry vein are ore-forming parent rock,formation andwall rock is mainly sandstone,marble of Yuquan group and slate,sandy slate ofPingshan group,the NE and NW structure are major ore-control structure,ore bodiesare mainly occurrence within the interlaminar fracture structure.Based on a variety ofdifferent types of ore-prospecting criteria, as well as regional aeromagnetic structuralinterpretation, combined with the geological background in the study area,we believethat mining area periphery has the potential of looking for the same types of deposits.