The optimal conditions for the complexation reaction of meso- tetra(3-methoxy-4-hy-droxyphenyl) porphine T(3-M-4HP)P with platinum and rhodium are presented. Beer' s Law is obeyed when the concentration of rhodium...The optimal conditions for the complexation reaction of meso- tetra(3-methoxy-4-hy-droxyphenyl) porphine T(3-M-4HP)P with platinum and rhodium are presented. Beer' s Law is obeyed when the concentration of rhodium is in the range of 0. 45-1.15 μg/25mL. The molar absorptivity of rhodium was found to be 1.99×106 L·mol-1·cm-1 at 460 nm. The value of εPt was found to be 6. 28×105 L·mol-1·cm-1 by linear regression method. The K coefficient method and compensating coefficient were used to determine platinum and rhodium simultaneouly without removal or masking of the interferents in the sample. The results for the determination of platinum and rhodium in the mixed solution of platinum and rhodium are satisfactory.展开更多
As a window of insight into the lower crust, high pressure granulite has received much attention since last decade. Yushugou high pressure granulite-peridotite Complex was located in the northeast margin of Southern T...As a window of insight into the lower crust, high pressure granulite has received much attention since last decade. Yushugou high pressure granulite-peridotite Complex was located in the northeast margin of Southern Tianshan, NW China. Previous ideas agreed that the peridotite unit in Yushugou, combined with the ultramafic rocks in Tonghuashan and Liuhuangshan, represent an ophiolite belt. However, the metamorphic evolution and tectonic mechanism of the Yushugou high pressure （HP） granulite remain controversial. Petrological investigations and phase equilibrium modelling for two representative fclsic granulitc samples suggest two stages metamorphism of the rocks in Yushugou Complex. Granulite facies metamorphism （Stage I） with P-T conditions of 9.8-10.4 kbar at 895-920℃ was recorded by the porphyroblastic garnet core; HP granulite facies metamorphism （Stage II） shows P-T conditions of 13.2-13.5 kbar at 845-860℃, based on the increasing grossular and decreasing pyrope contents of garnet rims. The Yushugou HP felsic granulites have recorded an anti- clockwise P-T path, characterized by the temperature decreasing and pressure increasing simultaneously. The LA-ICP-MS isotopic investigations on zircons from the felsic granulite show that the protolith ages of the granlulites are -430 Ma, with two age groups of-390 Ma and 340-350 Ma from the metamorphic rims of zircon, indicating the Stage I and II metamorphic events, respectively. A tectonic model was proposed to interpret the processes. The investigated felsic granulite was derived from deep rooted hanging wall, with Stage I granulite facies metamorphism of -390 Ma, which may he related to the Devonian arc magmatic intrusion; Stage II HP granulite facies metamorphism （340-350 Ma） may due to the involvement of being captured into the subducting slab and experienced the high pressure metamorphism.展开更多
Metapelite is one of the predominant rock types in the high-pressure–ultrahigh-pressure（HP–UHP） metamorphic belt of western Tianshan, NW China; however, the spatial and temporal variations of this belt during meta...Metapelite is one of the predominant rock types in the high-pressure–ultrahigh-pressure（HP–UHP） metamorphic belt of western Tianshan, NW China; however, the spatial and temporal variations of this belt during metamorphism are poorly understood. In this study, we present comparative petrological studies and 40^Ar/39 ^Ar geochronology of HP and UHP pelitic schist exposed along the Habutengsu valley. The schist mainly comprises quartz, white mica, garnet, albite and bluish amphibole. In the Mn O–Na2O–Ca O–K2O–Fe O–Mg O–Al2O3–Si O2–H2O（Mn NCKFMASH） system, P–T pseudosections were constructed using THERMOCALC 333 for two representative pelitic schists. The results demonstrate that there was a break in the peak metamorphic pressures in the Habutengsu area. The northern schist has experienced UHP metamorphism, consistent with the presence of coesite in the same section, while the southern one formed at lower pressures that stabilized the quartz. This result supports the previous finding of a metamorphic gradient through the HP–UHP metamorphic belt of the Chinese western Tianshan by the authors. Additionally, phengite in the northern schist was modelled as having a Si content of 3.55–3.70（a.p.f.u.） at the peak stage, a value much higher than that of oriented matrix phengite（Si content 3.32–3.38 a.p.f.u.）. This indicates that the phengite flakes in the UHP schist were subjected to recrystallization during exhumation, which is consistent with the presence of phengite aggregates surrounding garnet porphyroblast. The 40^Ar/39^ Ar age spectra of white mica（dominantly phengite） from the two schists exhibit similar plateau ages of ca. 315 Ma, which is interpreted as the timing of a tectonometamorphic event that occurred during the exhumation of the HP–UHP metamorphic belt of the Chinese western Tianshan.展开更多
This paper is supported by the Special Doctoral Grant of the Ministry of Education of China （No. 98049114） and the National Natural Science Foundation of China （No. 49972023）.
Permo-Triassic high-pressure(HP) mafic granulites, together with the Bibong retrogressed eclogite,preserved along the central western Korean Peninsula provide important insights into the Late Permian to Triassic colli...Permo-Triassic high-pressure(HP) mafic granulites, together with the Bibong retrogressed eclogite,preserved along the central western Korean Peninsula provide important insights into the Late Permian to Triassic collisional orogeny in northeast Asia. The metamorphic pressureetemperatureetime(P-T-t)paths of these rocks, however, remain poorly constrained and even overestimated, owing to outdated geothermobarometers and inaccurate isopleth techniques. Here we evaluate the metamorphic Pe T conditions of Triassic HP mafic granulites including those in Baekdong, Sinri and Daepan and the Bibong Triassic retrogressed eclogite in the Hongseong area, and the Permo-Triassic Samgot mafic granulite in the Imjingang Belt of the central western Korean Peninsula through the application of modern phase equilibria techniques. The Baekdong and Samgot mafic granulites and the Bibong retrogressed eclogite yield a range of 12.0 -16.0 kbar and 800 -900℃, representing HP granulite facies conditions. The Sinri and Daepan granulites from the Hongseong area show relatively lower grade metamorphic conditions between HP granulite and normal granulite facies, and are characterized by sub-isothermal decompression during exhumation. The similarities in the metamorphic ages and the post-collisional igneous activity from the central western Korean Peninsula indicate that the Triassic ages represent the retrograde stage of the metamorphic Pe T paths. In contrast, the Late Permian metamorphic ages, which are older than protolith ages of the post-collisional igneous rocks, correspond to the possible prograde stage of metamorphism. The P-T-t paths presented in this paper, together with the metamorphic ages and post-orogenic igneous events reported from these areas suggest trace of the subduction, accretion and exhumation history, and indicate a tectonic linkage among the northeast Asian continents during the Paleo-Tethyan Ocean closure.展开更多
文摘The optimal conditions for the complexation reaction of meso- tetra(3-methoxy-4-hy-droxyphenyl) porphine T(3-M-4HP)P with platinum and rhodium are presented. Beer' s Law is obeyed when the concentration of rhodium is in the range of 0. 45-1.15 μg/25mL. The molar absorptivity of rhodium was found to be 1.99×106 L·mol-1·cm-1 at 460 nm. The value of εPt was found to be 6. 28×105 L·mol-1·cm-1 by linear regression method. The K coefficient method and compensating coefficient were used to determine platinum and rhodium simultaneouly without removal or masking of the interferents in the sample. The results for the determination of platinum and rhodium in the mixed solution of platinum and rhodium are satisfactory.
基金financially supported by the National Natural Science Foundation of China(Grants 41330210,41520104004)
文摘As a window of insight into the lower crust, high pressure granulite has received much attention since last decade. Yushugou high pressure granulite-peridotite Complex was located in the northeast margin of Southern Tianshan, NW China. Previous ideas agreed that the peridotite unit in Yushugou, combined with the ultramafic rocks in Tonghuashan and Liuhuangshan, represent an ophiolite belt. However, the metamorphic evolution and tectonic mechanism of the Yushugou high pressure （HP） granulite remain controversial. Petrological investigations and phase equilibrium modelling for two representative fclsic granulitc samples suggest two stages metamorphism of the rocks in Yushugou Complex. Granulite facies metamorphism （Stage I） with P-T conditions of 9.8-10.4 kbar at 895-920℃ was recorded by the porphyroblastic garnet core; HP granulite facies metamorphism （Stage II） shows P-T conditions of 13.2-13.5 kbar at 845-860℃, based on the increasing grossular and decreasing pyrope contents of garnet rims. The Yushugou HP felsic granulites have recorded an anti- clockwise P-T path, characterized by the temperature decreasing and pressure increasing simultaneously. The LA-ICP-MS isotopic investigations on zircons from the felsic granulite show that the protolith ages of the granlulites are -430 Ma, with two age groups of-390 Ma and 340-350 Ma from the metamorphic rims of zircon, indicating the Stage I and II metamorphic events, respectively. A tectonic model was proposed to interpret the processes. The investigated felsic granulite was derived from deep rooted hanging wall, with Stage I granulite facies metamorphism of -390 Ma, which may he related to the Devonian arc magmatic intrusion; Stage II HP granulite facies metamorphism （340-350 Ma） may due to the involvement of being captured into the subducting slab and experienced the high pressure metamorphism.
基金financially supported by National Natural Science Foundation of China(Nos 41372004,41330210,41121062)
文摘Metapelite is one of the predominant rock types in the high-pressure–ultrahigh-pressure（HP–UHP） metamorphic belt of western Tianshan, NW China; however, the spatial and temporal variations of this belt during metamorphism are poorly understood. In this study, we present comparative petrological studies and 40^Ar/39 ^Ar geochronology of HP and UHP pelitic schist exposed along the Habutengsu valley. The schist mainly comprises quartz, white mica, garnet, albite and bluish amphibole. In the Mn O–Na2O–Ca O–K2O–Fe O–Mg O–Al2O3–Si O2–H2O（Mn NCKFMASH） system, P–T pseudosections were constructed using THERMOCALC 333 for two representative pelitic schists. The results demonstrate that there was a break in the peak metamorphic pressures in the Habutengsu area. The northern schist has experienced UHP metamorphism, consistent with the presence of coesite in the same section, while the southern one formed at lower pressures that stabilized the quartz. This result supports the previous finding of a metamorphic gradient through the HP–UHP metamorphic belt of the Chinese western Tianshan by the authors. Additionally, phengite in the northern schist was modelled as having a Si content of 3.55–3.70（a.p.f.u.） at the peak stage, a value much higher than that of oriented matrix phengite（Si content 3.32–3.38 a.p.f.u.）. This indicates that the phengite flakes in the UHP schist were subjected to recrystallization during exhumation, which is consistent with the presence of phengite aggregates surrounding garnet porphyroblast. The 40^Ar/39^ Ar age spectra of white mica（dominantly phengite） from the two schists exhibit similar plateau ages of ca. 315 Ma, which is interpreted as the timing of a tectonometamorphic event that occurred during the exhumation of the HP–UHP metamorphic belt of the Chinese western Tianshan.
基金This paper is supported by the Special Doctoral Grant of the Ministry ofEducation of China(No.98049114)and the National Natural Science Foundation of China(No.49972023).
文摘This paper is supported by the Special Doctoral Grant of the Ministry of Education of China （No. 98049114） and the National Natural Science Foundation of China （No. 49972023）.
基金supported by a Basic Research Project (GP2017021 Development of integrated geological information based on digital mapping) of the Korea Institute of Geoscience and Mineral Resources (KIGAM)+1 种基金funded by the Ministry of Science, Information, Communication and Technology (ICT),and Future Planning, Koreasupported partially by the Basic Science Research Program through the National Research Foundation (NRF) funded by the Ministry of Science and ICT 2013R1A1A2058070, 2017R1D1A1B04028521 to H.S. Kim, and 2015R1D1A1A09058914, 2017R1A6A1A07015374 to S. Kwon
文摘Permo-Triassic high-pressure(HP) mafic granulites, together with the Bibong retrogressed eclogite,preserved along the central western Korean Peninsula provide important insights into the Late Permian to Triassic collisional orogeny in northeast Asia. The metamorphic pressureetemperatureetime(P-T-t)paths of these rocks, however, remain poorly constrained and even overestimated, owing to outdated geothermobarometers and inaccurate isopleth techniques. Here we evaluate the metamorphic Pe T conditions of Triassic HP mafic granulites including those in Baekdong, Sinri and Daepan and the Bibong Triassic retrogressed eclogite in the Hongseong area, and the Permo-Triassic Samgot mafic granulite in the Imjingang Belt of the central western Korean Peninsula through the application of modern phase equilibria techniques. The Baekdong and Samgot mafic granulites and the Bibong retrogressed eclogite yield a range of 12.0 -16.0 kbar and 800 -900℃, representing HP granulite facies conditions. The Sinri and Daepan granulites from the Hongseong area show relatively lower grade metamorphic conditions between HP granulite and normal granulite facies, and are characterized by sub-isothermal decompression during exhumation. The similarities in the metamorphic ages and the post-collisional igneous activity from the central western Korean Peninsula indicate that the Triassic ages represent the retrograde stage of the metamorphic Pe T paths. In contrast, the Late Permian metamorphic ages, which are older than protolith ages of the post-collisional igneous rocks, correspond to the possible prograde stage of metamorphism. The P-T-t paths presented in this paper, together with the metamorphic ages and post-orogenic igneous events reported from these areas suggest trace of the subduction, accretion and exhumation history, and indicate a tectonic linkage among the northeast Asian continents during the Paleo-Tethyan Ocean closure.
