A thrust and nappe tectonic zone with imbricate branch thrusts is developed along the southern margin of the coal-forming region of North China. This tectonic zone is tightly related to the Qinling-Dabie collision oro...A thrust and nappe tectonic zone with imbricate branch thrusts is developed along the southern margin of the coal-forming region of North China. This tectonic zone is tightly related to the Qinling-Dabie collision orogen in genesis and belongs to the frontal zone of a huge thrust system developed during Yanshanian episode at the northern foot of the orogen. It is pointed out that thrusting had distorted the original depositional margin of the coal-forming region and some new coal-bearing blocks would be found out in the frontal sheets and under the undulate sole thrust.展开更多
Tectonically deformed coal(TDC)develops because of the superimposed deformation and metamorphism of a coal seam by tectonic movements.The migration and accumulation of trace elements in TDC is largely in response to s...Tectonically deformed coal(TDC)develops because of the superimposed deformation and metamorphism of a coal seam by tectonic movements.The migration and accumulation of trace elements in TDC is largely in response to stress-strain conditions.To develop a law governing the migration and aggregation of sensitive elements and investigate the geological controls on TDC,coal samples from different deformation sequences were collected from the Haizi mine,in the Huaibei coalfield in Anhui Province,China,and the concentrations of 49 elements were determined by XRF and ICP-MS,and then microscopically analyzed.The results show that the distribution and morphology of minerals in coal is related to the deformation degree of TDC.The evolutionary process runs from orderly distribution of minerals in a weak brittle deformed coal to disordered distributions in ductile deformed coal.According to the elemental distribution characteristics in TDC,four types of element migration can be identified:stable,aggregate,declining,and undulate types,which are closely related to the deformation degree of TDC.Present data indicate that the overall distribution of rare earth elements(REE)does not change with metamorphism and deformation,but it shows obvious dynamic differentiation phenomena along with the deformation of TDC.Tectonic action after coal-formation,brittle or ductile deformation,and the metamorphic mechanism and its accompanying dynamic thermal effects are the main factors that influence the redistribution of elements in TDC.We conclude that tectonic movements provide the motivation and basis for the redistribution of elements and the paths and modes of element migration are controlled by brittle and ductile deformation metamorphic processes.The dynamic thermal effect has the most significant effect on coal metamorphism and tectonic-stress-accelerated element migration and accumulation.These factors then induce the tectonic-dynamic differentiation phenomenon of element migration.展开更多
基金This project was supported by the Coal Science Foundation of China
文摘A thrust and nappe tectonic zone with imbricate branch thrusts is developed along the southern margin of the coal-forming region of North China. This tectonic zone is tightly related to the Qinling-Dabie collision orogen in genesis and belongs to the frontal zone of a huge thrust system developed during Yanshanian episode at the northern foot of the orogen. It is pointed out that thrusting had distorted the original depositional margin of the coal-forming region and some new coal-bearing blocks would be found out in the frontal sheets and under the undulate sole thrust.
基金supported by National Science and Technology Major Project(Grant No.2011ZX05034)the Research Fund of Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process,Ministry of Education(Grant No.2013-007)+1 种基金Innovation of Graduate Student Training Project in Jiangsu Province(Grant No.CXZZ13-0944)Fundamental Research Funds for the Central Universities(Grant No.2013XK06)
文摘Tectonically deformed coal(TDC)develops because of the superimposed deformation and metamorphism of a coal seam by tectonic movements.The migration and accumulation of trace elements in TDC is largely in response to stress-strain conditions.To develop a law governing the migration and aggregation of sensitive elements and investigate the geological controls on TDC,coal samples from different deformation sequences were collected from the Haizi mine,in the Huaibei coalfield in Anhui Province,China,and the concentrations of 49 elements were determined by XRF and ICP-MS,and then microscopically analyzed.The results show that the distribution and morphology of minerals in coal is related to the deformation degree of TDC.The evolutionary process runs from orderly distribution of minerals in a weak brittle deformed coal to disordered distributions in ductile deformed coal.According to the elemental distribution characteristics in TDC,four types of element migration can be identified:stable,aggregate,declining,and undulate types,which are closely related to the deformation degree of TDC.Present data indicate that the overall distribution of rare earth elements(REE)does not change with metamorphism and deformation,but it shows obvious dynamic differentiation phenomena along with the deformation of TDC.Tectonic action after coal-formation,brittle or ductile deformation,and the metamorphic mechanism and its accompanying dynamic thermal effects are the main factors that influence the redistribution of elements in TDC.We conclude that tectonic movements provide the motivation and basis for the redistribution of elements and the paths and modes of element migration are controlled by brittle and ductile deformation metamorphic processes.The dynamic thermal effect has the most significant effect on coal metamorphism and tectonic-stress-accelerated element migration and accumulation.These factors then induce the tectonic-dynamic differentiation phenomenon of element migration.
