Geology And Mineralization In Antuoling Mo Deposit,Hebei

Antuoling porphyry molybdenum deposit is one of the most important metal deposits of polymetallic mineralization belt in north Taihang Mountain.It is located in the tectonomagmatic belt of NNE-trending,which is controlled by Wulonggou and Zijingguan fault zone.This study based on the research of the geologic feature of Antuoling molybdenum deposit,trace the source of ore-forming materials through the characters of the rhenium,lead and sulfur isotope.The origin and evolution of the ore-forming fluids is discussed by means of the study of the fluid inclusion and oxygen and hydrogen isotope.The age of the rock and the orebody are definited by means of the isotopic geochronology.At last,the paper make a preliminary exploration of the metallogenic mechanism.In combination with the study of fluid inclusion and the character of H-O Isotope,considering Antuoling molybdenum deposit belongs to middle-high tempreture and salinity deposit.From early to late stage of mineralization,the ore-forming fluid evolves from high temperature,high salinity,and rich carbon dioxide to middle-low temperature,low salinity and poor carbon dioxide.The sulphur isotope of pyrite indicates that the sulfur may roots in deep magma and mixed with the sulfur of the upper mantle.The lead isotope of molybdenite and pyrite are changed little,and show that it mainly derived from the deep crust.The rhenium isotope of molybdenite is also within the numerical range of crust and mantle source.So implication of the three isotope above have a good consistency,they all elucidate the ore-forming material roots in upper mantle and lower crust.The U-Pb isotopic age data of Zircon of Antuoling granodiorite porphyry indicates that the intrusive age of granodiorite porphyry is(136.6±1.3)Ma.The Re-Os isotopic age data of molybdenite indicates that the mineralization age of the deposit is(147.3 ± 3.7)Ma.Although the results of the two tests show that the rock is younger than the ore,but the numerical results are similer,and indicate that both diagenesis and mineralization are the productions of structure-magma-fluid activities in the middle-late YanShanian period.Extensive crust-mantle interaction took place on background of the transition of regional stress field.The granitoid magma formed and rise along the fault,and invade the fuping group.After magmatic stage,mineral precipitation happened when Crust mantle mixed hydrothermal fluid ascending.Mineralization ended with the mixing of the meteoric water.