Deep carbonate reservoirs affected by prominent strike-slip faults represent crucial targets in oil and gas exploration owing to their immense resource potential.However,the complex geological environments and poorly ...Deep carbonate reservoirs affected by prominent strike-slip faults represent crucial targets in oil and gas exploration owing to their immense resource potential.However,the complex geological environments and poorly understood histories of the associated paleo-fluid activity have hindered the development of robust theories regarding pore formation and preservation mechanisms,resulting in suboptimal exploration strategies.Leveraging the extensive well deployment by the China Sinopec Group in the Shunbei area of the Tarim Basin,this study addresses these challenges by establishing a comprehensive framework for the evolution of diagenetic fluids within the Middle-Lower Ordovician carbonate formations.Using core samples,thin-section analysis,and cathodoluminescence observations,this study employs high-resolution geochemical methodologies,including isotopic analyses,rare earth element profiling,fluid inclusion studies,and uranium-lead dating,as primary tools for identifying and interpreting paleo-fluid characteristics across various rock types and calcite cement varieties within this stratigraphic interval.The findings reveal several key insights:(i)both RFC and C1 cements are derived from seawater,with C1 forming under burial conditions;(ii)C2,C3,and VC cements result from distinct tectonic events,specifically during the first and third episodes of the Middle Caledonian movement,with meteoric water infiltrating fault systems independently of orogenic belts or paleo-karst systems;and(iii)previous conclusions are challenged,as the influence of hydrothermal activity in this area is found to be minimal.Furthermore,the model presented here serves as a valuable reference for understanding fluid activity events at distal locations within orogenic belts under compressive stress,while accurately capturing fluid variations over different temporal scales within fault zones plays a decisive role.展开更多
Based on a functional group composite strategy,the first Ag-containing phosphate-tellurite nonlinear optical(NLO)crystal,Ag(Te_(2)O_(3))(PO_(4)),was synthesized via a subcritical hydrothermal method.This crystal cryst...Based on a functional group composite strategy,the first Ag-containing phosphate-tellurite nonlinear optical(NLO)crystal,Ag(Te_(2)O_(3))(PO_(4)),was synthesized via a subcritical hydrothermal method.This crystal crystallizes in the noncentrosymmetric space group Pmn2_(1),featuring a unique zigzag two-dimensional[(Te_(2)O_(3))(PO_(4))]_(∞)layer.It possesses the strongest powder second-harmonic generation(SHG)response among all reported phosphate-tellurite compounds,reaching 2.1×KH_(2)PO_(4),along with a moderate birefringence of 0.045@546 nm.Theoretical calculations indicate that the TeO_(4)group with stereochemically active lone-pair electrons,together with AgO_(7)polyhedra and PO_(4)group,synergistically contributes to its optical properties.This functional group composite strategy not only facilitates the integration of phosphate and tellurite units with Ag+cations,but also offers a versatile route for designing NLO materials across diverse inorganic systems.展开更多
基金supported by the National Natural ScienceFoundation of China(42102191)。
文摘Deep carbonate reservoirs affected by prominent strike-slip faults represent crucial targets in oil and gas exploration owing to their immense resource potential.However,the complex geological environments and poorly understood histories of the associated paleo-fluid activity have hindered the development of robust theories regarding pore formation and preservation mechanisms,resulting in suboptimal exploration strategies.Leveraging the extensive well deployment by the China Sinopec Group in the Shunbei area of the Tarim Basin,this study addresses these challenges by establishing a comprehensive framework for the evolution of diagenetic fluids within the Middle-Lower Ordovician carbonate formations.Using core samples,thin-section analysis,and cathodoluminescence observations,this study employs high-resolution geochemical methodologies,including isotopic analyses,rare earth element profiling,fluid inclusion studies,and uranium-lead dating,as primary tools for identifying and interpreting paleo-fluid characteristics across various rock types and calcite cement varieties within this stratigraphic interval.The findings reveal several key insights:(i)both RFC and C1 cements are derived from seawater,with C1 forming under burial conditions;(ii)C2,C3,and VC cements result from distinct tectonic events,specifically during the first and third episodes of the Middle Caledonian movement,with meteoric water infiltrating fault systems independently of orogenic belts or paleo-karst systems;and(iii)previous conclusions are challenged,as the influence of hydrothermal activity in this area is found to be minimal.Furthermore,the model presented here serves as a valuable reference for understanding fluid activity events at distal locations within orogenic belts under compressive stress,while accurately capturing fluid variations over different temporal scales within fault zones plays a decisive role.
基金support by the National Natural Science Foundation of China(22375147,52332001,22305174)the National Key Research and Development Plan of the Ministry of Science and Technology(2023YFF0718900)the Natural Science Foundation of Tianjin City(22JCYBJC01380).
文摘Based on a functional group composite strategy,the first Ag-containing phosphate-tellurite nonlinear optical(NLO)crystal,Ag(Te_(2)O_(3))(PO_(4)),was synthesized via a subcritical hydrothermal method.This crystal crystallizes in the noncentrosymmetric space group Pmn2_(1),featuring a unique zigzag two-dimensional[(Te_(2)O_(3))(PO_(4))]_(∞)layer.It possesses the strongest powder second-harmonic generation(SHG)response among all reported phosphate-tellurite compounds,reaching 2.1×KH_(2)PO_(4),along with a moderate birefringence of 0.045@546 nm.Theoretical calculations indicate that the TeO_(4)group with stereochemically active lone-pair electrons,together with AgO_(7)polyhedra and PO_(4)group,synergistically contributes to its optical properties.This functional group composite strategy not only facilitates the integration of phosphate and tellurite units with Ag+cations,but also offers a versatile route for designing NLO materials across diverse inorganic systems.
