Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) was used to analyze chemical elements—major, trace and rare earth elements (REE) concentrations, augmented with quantitative X-ray diffraction (XRD) analysis and ...Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) was used to analyze chemical elements—major, trace and rare earth elements (REE) concentrations, augmented with quantitative X-ray diffraction (XRD) analysis and thin-section petrography for mineralogical characterization of the Triassic Montney Formation in northeastern British Columbia, Western Canada Sedimentary Basin (WCSB). Results from this study indicate that integration of chemical elements with mineralogy shows affinity to the host lithologies. Evidently, chemical elements are the building blocks for minerals, thus, their significances in the interpretation of geological systems are unambiguous. Herein, major elements concentration such as Al, Fe, K, Mg, Ca, Mn in the samples analyzed from the Montney Formation are interpreted as: 1) indication of dolomitization and diagenesis;2) trace elements—Rb, Th, U, and Cs are related to the organic matter—kerogen in the clay component of the Montney Formation source rock;and 3) transition metals—Sc, V, Co, Cr, Zn show strong affinity with diagenesis in the study interval.展开更多
Objective The Altyn Tagh marks the northern margin of the Qinghai-Tibet Plateau and lies between the Tarim block to the north and the Qaidam block,Qilian Orogen,and Kunlun orogenic belt to the south.The Altyn Tagh reg...Objective The Altyn Tagh marks the northern margin of the Qinghai-Tibet Plateau and lies between the Tarim block to the north and the Qaidam block,Qilian Orogen,and Kunlun orogenic belt to the south.The Altyn Tagh region contains ophiolite,high-to ultrahigh-pressure metamorphic rocks,and igneous rocks.Previous research has virified the occurrence of continental rifting,subduction,slab roll-back,and collision between the Tarim block and Proto-Tethys oceanic plate.Moreover,Kaladaban volcanic rocks are mainly distributed in the north Altyn region.Studies of the magmatic evolution of this region have proposed that Altyn oceanic plate was subducted during the Ordovician(Han et al.,2012;Wang et al.,2017).However,the specific timing and other aspects of the subduction are debated,and an investigation of granite porphyry in the Kaladaban area would improve our understanding of this subduction event.In this study,we present new U-Pb zircon dating result and Sr-Nd isotope composition data for granite porphyry from the North Altyn region.The objective is to constrain the timing of subduction of the North Altyn oceanic plate and establish the petrogenesis and magma source of the granite porphyry.展开更多
Ophiolites along the E-W trending Yarlung-Tsangpo Suture(YTS),which separates the Indian plate from the Eurasian plate,have been regarded as relics of the NeoTethyan Ocean.The Xigaze ophiolite in the central YTS
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)<span style="font-size:12px;font-family:Verdana;"><span style="font-size:12px;font-family:Verdana;"> </span></span><s...Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)<span style="font-size:12px;font-family:Verdana;"><span style="font-size:12px;font-family:Verdana;"> </span></span><span style="font-size:12px;font-family:Verdana;">was used to analyze </span><span style="font-size:10pt;font-family:'}', serif;"><span style="font-size:12px;font-family:Verdana;">chemical elements—</span><span style="font-size:12px;font-family:Verdana;">major, trace and rare earth elements</span><span style="font-size:12px;font-family:Verdana;"> </span><span style="font-size:12px;font-family:Verdana;">(REE) concentrations, </span></span><span style="font-size:10.0pt;font-family:" color:#222222;"=""><span style="font-size:12px;font-family:Verdana;">augmented with quantitative X-ray diffraction (XRD) analysis and thin-section petrography for</span><span style="font-size:12px;font-family:Verdana;"> </span></span><span style="font-size:10pt;font-family:'}', serif;"><span style="font-size:12px;font-family:Verdana;">mineralogical characterization of the Triassic Montney Formation in northeastern British Columbia, Western Canada Sedimentary</span><span style="font-size:12px;font-family:Verdana;"> </span><span style="font-size:12px;font-family:Verdana;">Basin (WCSB). Results from this study indicate</span><span style="font-size:12px;font-family:Verdana;"> </span><span style="font-size:12px;font-family:Verdana;">that integration of chemical elements with mineralogy shows affinity to the host lithologies. Evidently, chemical elements are the building blocks for minerals, thus, their significances</span><span style="font-size:12px;font-family:Verdana;"> </span><span style="font-size:12px;font-family:Verdana;">in the interpretation of geological systems are unambiguous. Herein, major elements concentration such as Al, Fe, K, Mg, Ca, Mn in the samples analyzed from the Montney Formation are interpreted as: 1) indication of dolomitization and diagenesis;2) trace elements—Rb, Th, U, and Cs are related to the organic matter—kerogen in the clay component of the Montney Formation source rock;and 3) transition metals—Sc, V, Co, Cr, Zn show strong affinity with diagenesis in the study interval.</span></span>展开更多
The 65 whole-rock REE samples studied come from the classic sections of Early Cambrian to Early Silurian in the Yichang area, Hubei Province. REE concentrations tested on ICP-AES are normalized to the North American S...The 65 whole-rock REE samples studied come from the classic sections of Early Cambrian to Early Silurian in the Yichang area, Hubei Province. REE concentrations tested on ICP-AES are normalized to the North American Shale Composite (NASC), and Ce anomaly values are calculated based on log[3Cen(2Lan+Ndn)]. With the whole-rock Ce anomaly used as a quantitative index of sea-level changes, 5 prominent eustatic circles are recognized, and a good corresponding relationship is observed between the black shale episodes and the transgressive events. On account of the global distributions of coeval black shales and the specified paleogeographic background of South China, a genetic hypothesis based on the model of O2-minimum zone expansion is suggested for the Early Paleozoic multi-episode black shales in South China.展开更多
文摘Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) was used to analyze chemical elements—major, trace and rare earth elements (REE) concentrations, augmented with quantitative X-ray diffraction (XRD) analysis and thin-section petrography for mineralogical characterization of the Triassic Montney Formation in northeastern British Columbia, Western Canada Sedimentary Basin (WCSB). Results from this study indicate that integration of chemical elements with mineralogy shows affinity to the host lithologies. Evidently, chemical elements are the building blocks for minerals, thus, their significances in the interpretation of geological systems are unambiguous. Herein, major elements concentration such as Al, Fe, K, Mg, Ca, Mn in the samples analyzed from the Montney Formation are interpreted as: 1) indication of dolomitization and diagenesis;2) trace elements—Rb, Th, U, and Cs are related to the organic matter—kerogen in the clay component of the Montney Formation source rock;and 3) transition metals—Sc, V, Co, Cr, Zn show strong affinity with diagenesis in the study interval.
基金jointly supported by the National Key R&D Program of China(Grant No.2018YFC0603704)a Geological Survey Project of the China Geological Survey(DD20160050).
文摘Objective The Altyn Tagh marks the northern margin of the Qinghai-Tibet Plateau and lies between the Tarim block to the north and the Qaidam block,Qilian Orogen,and Kunlun orogenic belt to the south.The Altyn Tagh region contains ophiolite,high-to ultrahigh-pressure metamorphic rocks,and igneous rocks.Previous research has virified the occurrence of continental rifting,subduction,slab roll-back,and collision between the Tarim block and Proto-Tethys oceanic plate.Moreover,Kaladaban volcanic rocks are mainly distributed in the north Altyn region.Studies of the magmatic evolution of this region have proposed that Altyn oceanic plate was subducted during the Ordovician(Han et al.,2012;Wang et al.,2017).However,the specific timing and other aspects of the subduction are debated,and an investigation of granite porphyry in the Kaladaban area would improve our understanding of this subduction event.In this study,we present new U-Pb zircon dating result and Sr-Nd isotope composition data for granite porphyry from the North Altyn region.The objective is to constrain the timing of subduction of the North Altyn oceanic plate and establish the petrogenesis and magma source of the granite porphyry.
文摘Ophiolites along the E-W trending Yarlung-Tsangpo Suture(YTS),which separates the Indian plate from the Eurasian plate,have been regarded as relics of the NeoTethyan Ocean.The Xigaze ophiolite in the central YTS
文摘Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)<span style="font-size:12px;font-family:Verdana;"><span style="font-size:12px;font-family:Verdana;"> </span></span><span style="font-size:12px;font-family:Verdana;">was used to analyze </span><span style="font-size:10pt;font-family:'}', serif;"><span style="font-size:12px;font-family:Verdana;">chemical elements—</span><span style="font-size:12px;font-family:Verdana;">major, trace and rare earth elements</span><span style="font-size:12px;font-family:Verdana;"> </span><span style="font-size:12px;font-family:Verdana;">(REE) concentrations, </span></span><span style="font-size:10.0pt;font-family:" color:#222222;"=""><span style="font-size:12px;font-family:Verdana;">augmented with quantitative X-ray diffraction (XRD) analysis and thin-section petrography for</span><span style="font-size:12px;font-family:Verdana;"> </span></span><span style="font-size:10pt;font-family:'}', serif;"><span style="font-size:12px;font-family:Verdana;">mineralogical characterization of the Triassic Montney Formation in northeastern British Columbia, Western Canada Sedimentary</span><span style="font-size:12px;font-family:Verdana;"> </span><span style="font-size:12px;font-family:Verdana;">Basin (WCSB). Results from this study indicate</span><span style="font-size:12px;font-family:Verdana;"> </span><span style="font-size:12px;font-family:Verdana;">that integration of chemical elements with mineralogy shows affinity to the host lithologies. Evidently, chemical elements are the building blocks for minerals, thus, their significances</span><span style="font-size:12px;font-family:Verdana;"> </span><span style="font-size:12px;font-family:Verdana;">in the interpretation of geological systems are unambiguous. Herein, major elements concentration such as Al, Fe, K, Mg, Ca, Mn in the samples analyzed from the Montney Formation are interpreted as: 1) indication of dolomitization and diagenesis;2) trace elements—Rb, Th, U, and Cs are related to the organic matter—kerogen in the clay component of the Montney Formation source rock;and 3) transition metals—Sc, V, Co, Cr, Zn show strong affinity with diagenesis in the study interval.</span></span>
文摘The 65 whole-rock REE samples studied come from the classic sections of Early Cambrian to Early Silurian in the Yichang area, Hubei Province. REE concentrations tested on ICP-AES are normalized to the North American Shale Composite (NASC), and Ce anomaly values are calculated based on log[3Cen(2Lan+Ndn)]. With the whole-rock Ce anomaly used as a quantitative index of sea-level changes, 5 prominent eustatic circles are recognized, and a good corresponding relationship is observed between the black shale episodes and the transgressive events. On account of the global distributions of coeval black shales and the specified paleogeographic background of South China, a genetic hypothesis based on the model of O2-minimum zone expansion is suggested for the Early Paleozoic multi-episode black shales in South China.
