Mesozoic and Cenozoic magma activity in the Wolong Lake mining area of Huaibei is frequent,and the degree of magma intrusion into coal seams remarkable.On the one hand,magma intrusion affects the utilization of coal r...Mesozoic and Cenozoic magma activity in the Wolong Lake mining area of Huaibei is frequent,and the degree of magma intrusion into coal seams remarkable.On the one hand,magma intrusion affects the utilization of coal resources;on the other hand,the macro and trace elements in coal are redistributed to form new mineral types.This study uses the Wolong Lake magma intrusion coal seam as a research object.The mineral paragenesis for igneous rock,coke,and thermally-altered coal in an igneous intrusion zone is studied using SEM,XRD,and Raman spectroscopy.During igneous intrusion,the temperature and pressure of igneous rock metamorphose ambient low-rank coal to high-rank coal and coke.The response mechanism of minerals and trace elements to magmatic intrusion is discussed.The results are:①SEM analysis shows that ankerite and pyrite are formed from magma intrusion.Both minerals are strongly developed in the magma-coal contact zone,and less well developed in thermally-altered coal.②XRD analysis shows that igneous intrusion strongly influences the types and content of minerals in coke and thermally-altered coal.In addition to the increase amounts of ankerite and pyrite,chlorite,serpentine,and muscovite,and other secondary minerals,are generated following igneous intrusion.③Raman analysis suggests that thermally-altered coal possesses the characteristics of both pyrite and coke.Coke from the magma-coal boundary zone possesses the typical characteristics of pyrite.Igneous rock contains a mineral similar to pyrite,confirmed by both having similar Raman peaks.The scattering intensity of Ag indicates that the formation pressure of pyrite increases from thermally-altered coal via the boundary between the coke zone and the igneous rock.展开更多
G. El Sela is located in the Southern Eastern Desert of Egypt cropping as two parts, occupied by monzogranites that were categorized as biotite granite, muscovite granite and two mica granites. The northern part is mo...G. El Sela is located in the Southern Eastern Desert of Egypt cropping as two parts, occupied by monzogranites that were categorized as biotite granite, muscovite granite and two mica granites. The northern part is more significant according its high concentrations of uranium that controlled by complicated structure regime;faulting, infrastructures and shearing are the most common structural criteria of this part. The Egyptian Nuclear Materials Authority (NMA) mined this part to produce the uranium ore. The previous mineralogical studies indicated that this granite was dominated by primary uranium minerals (pitchblende and coffinite) and secondary minerals belong to the autunite group (autunite, metautunite, phurcalite) in addition to uranophane. In the present work, petrographic and mineralogical studies are applied for the granites using the polarized and stereo microscopes and followed by electron microscope and XRD. The result of the microscopic examinations revealed the tectonic regime controlling the radioactivity and recognized the sodic autunite (meta-natroautunite) beside the pre-mentioned autunite group minerals completing the paragenetic sequrnce of these minerals. In this study, it is concluded that the sheared biotite granite is monzogranite originated during the episode of the continental plate collision (syncollision). The study finished to presence of two main types of the alteration corresponding to the two high levels of radioactivity (moderate and anomalous). The first is the thermal alteration (saussiritization, sericitization, kaolinization, silicification and hematization) and the second is the chemical transformation (oxidation, dehydration, ion substitutions and confusion) responsible for formation of the secondary uranium minerals. The temperature needed for the thermal alteration is sourced by the hydrothermal solutions, while the temperature needed for the uranium minerals transformation may be generated during the episode of the continental plate collision (syncollision). Paragenesis o展开更多
基金This work was supported by the National Natural Science Foundation of China(No.41373108 and 41702176)Natural Science Foundation of Anhui Province(No.1608085QD79)+1 种基金the Scientific and Technological Project of Huaibei Mining Industry(Group)Co.Ltd.(HK-2018-1)the Scientific and Technological Project of Anhui Traffic and Aviation Engineering(Group)Co.Ltd.We acknowledge the editors and reviewers for polishing the language and providing in-depth discussion.
文摘Mesozoic and Cenozoic magma activity in the Wolong Lake mining area of Huaibei is frequent,and the degree of magma intrusion into coal seams remarkable.On the one hand,magma intrusion affects the utilization of coal resources;on the other hand,the macro and trace elements in coal are redistributed to form new mineral types.This study uses the Wolong Lake magma intrusion coal seam as a research object.The mineral paragenesis for igneous rock,coke,and thermally-altered coal in an igneous intrusion zone is studied using SEM,XRD,and Raman spectroscopy.During igneous intrusion,the temperature and pressure of igneous rock metamorphose ambient low-rank coal to high-rank coal and coke.The response mechanism of minerals and trace elements to magmatic intrusion is discussed.The results are:①SEM analysis shows that ankerite and pyrite are formed from magma intrusion.Both minerals are strongly developed in the magma-coal contact zone,and less well developed in thermally-altered coal.②XRD analysis shows that igneous intrusion strongly influences the types and content of minerals in coke and thermally-altered coal.In addition to the increase amounts of ankerite and pyrite,chlorite,serpentine,and muscovite,and other secondary minerals,are generated following igneous intrusion.③Raman analysis suggests that thermally-altered coal possesses the characteristics of both pyrite and coke.Coke from the magma-coal boundary zone possesses the typical characteristics of pyrite.Igneous rock contains a mineral similar to pyrite,confirmed by both having similar Raman peaks.The scattering intensity of Ag indicates that the formation pressure of pyrite increases from thermally-altered coal via the boundary between the coke zone and the igneous rock.
文摘G. El Sela is located in the Southern Eastern Desert of Egypt cropping as two parts, occupied by monzogranites that were categorized as biotite granite, muscovite granite and two mica granites. The northern part is more significant according its high concentrations of uranium that controlled by complicated structure regime;faulting, infrastructures and shearing are the most common structural criteria of this part. The Egyptian Nuclear Materials Authority (NMA) mined this part to produce the uranium ore. The previous mineralogical studies indicated that this granite was dominated by primary uranium minerals (pitchblende and coffinite) and secondary minerals belong to the autunite group (autunite, metautunite, phurcalite) in addition to uranophane. In the present work, petrographic and mineralogical studies are applied for the granites using the polarized and stereo microscopes and followed by electron microscope and XRD. The result of the microscopic examinations revealed the tectonic regime controlling the radioactivity and recognized the sodic autunite (meta-natroautunite) beside the pre-mentioned autunite group minerals completing the paragenetic sequrnce of these minerals. In this study, it is concluded that the sheared biotite granite is monzogranite originated during the episode of the continental plate collision (syncollision). The study finished to presence of two main types of the alteration corresponding to the two high levels of radioactivity (moderate and anomalous). The first is the thermal alteration (saussiritization, sericitization, kaolinization, silicification and hematization) and the second is the chemical transformation (oxidation, dehydration, ion substitutions and confusion) responsible for formation of the secondary uranium minerals. The temperature needed for the thermal alteration is sourced by the hydrothermal solutions, while the temperature needed for the uranium minerals transformation may be generated during the episode of the continental plate collision (syncollision). Paragenesis o
