The Study Of Genetic Mineralogical Of Amphibole In Mesozoic Intrusive Rocks In Han-Xing Area,Southern Hebei Province

The Hanxing area in the south of Taihang Mountain is located in the middle of the North China Craton.The high magnesium diorite produced in this area is one of the main responses to the failure of the North China Craton and is of great significance to the study of the failure of the North China Craton.At the same time,the widely developed "Hanxing type iron ore" in this area is a typical skarn type iron ore in China.The iron ore in this area is characterized by large scale and high ore grade.Further study on the genesis and evolution of high magnesium diorite is of great geological significance for ore prospecting and Research on the failure mechanism of North China Craton.Taking genetic mineralogy as the research method and amphibole in different lithology as the research object,this paper analyzes the main and trace elements of amphibole by means of EPMA and LA-ICP-MS,and obtains the change information of physicochemical conditions during magma crystallization of different lithology by integrating field geological observation and petrographic research;Thus,the magmatic processes such as magma mixing and crystallization differentiation can be discussed,and the diagenetic metallogenic model in this area can be established.In addition,the amphibole information in intrusions with different metallogenic intensity is compared,such as Kuangshan intrusion in strong metallogenic area,Fushan intrusion in weak metallogenic area and Guzhen intrusion in non metallogenic area.To explore whether the metallogenic intensity of these metallogenic areas is related to the trace element characteristics of amphibole in the intrusion and the physicochemical conditions during crystallization.The Kuangshan intrusion of the central magmatic belt in Hanxing area is located in the strong metallogenic region,the Fushan intrusion of the Western magmatic belt is located in the weak metallogenic region,and the Guzhen intrusion is located in the non-metallogenic region.In this study on the major elements of amphibole in different intrusions,the F and Cl of amphibole in the Kuangshan intrusions(strong metallogenic area)are significantly higher than those in the other two intrusions,and the Fe O of amphibole in Guzhen intrusion(weak metallogenic area)is significantly higher than those in the other two intrusions,This shows that strong metallogenic areas have higher mineralizer F and Cl,which is conducive to mineralization,while weak metallogenic areas have more Fe in the form of oxide,which consumes too much Fe,which is not conducive to mineralization.The temperature pressure oxygen fugacity meters of amphibole minerals in different intrusions are systematically compared and analyzed.According to the crystallization depth of amphibole,amphibole is divided into type I amphibole(20 ~ 25 km crystallization in deep magma chamber),type II amphibole(10 ~ 20 km crystallization in shallow magma chamber)and type III amphibole(1 ~ 3 km crystallization in shallow magma chamber),Only type III amphibole was found in the intrusion of the Kuangshan,type I,II and III amphibole were found in the Fushan intrusion,and type I and III amphibole were found in the Guzhen intrusion.Through comprehensive research and analysis,The microscopic characteristics of secondary amphibole of shallow metasomatic crystallization show poor automorphism and uneven interference color.Thermobarometer calculation shows that the formation depth and temperature pressure of this part of amphibole are low,the water content of amphibole host magma is low,and the oxygen fugacity is high.The Si O2 content of amphibole ranges from47% to 55%,Al2O3 content ranges from 2% to 5%,and Nb content ranges from 5%×10-6to30%×10-6;The microscopic characteristics of deep crystalline primary amphibole show that the degree of automorphism is good,the interference color is uniform,the formation depth and temperature pressure of amphibole are high,the water content of amphibole host magma is high,the oxygen fugacity is low,amphibole has lower Si O2(39% ~ 45%),higher Al2O3(10% ~ 14%),and the content of trace element Nb is less than 2×10-6,Ta content is also lower.The test samples of this study show that the amphibole in the strong metallogenic area(Kuangshan intrusion)is shallow amphibole,and the amphibole in the weak metallogenic area(Fushan and Guzhen intrusions)also has deep crystallization.From the results shown in the Boxu diagram,the trace elements of amphibole minerals in the Kuangshan intrusion are more different than those in Fushan and Guzhen intrusions.Combined with the projection results of amphibole magma Ti O2-Al2O3 diagram,all the samples in the strong metallogenic area(Kuangshan intrusion)fall in the crust source and mantle crust mixed source area,and the samples in the weak metallogenic area(Fushan and Guzhen intrusions)have deeper magmatic sources,mainly from crust source,mantle source and mantle crust mixed source.