The Nangqen Basin is one of the typical shearing-extensional basins situated in the north part of the Hengduan Mts. Nine ages of the Cenozoic volcanic rocks from the basin by K-Ar isotope-dilution technique have been ...The Nangqen Basin is one of the typical shearing-extensional basins situated in the north part of the Hengduan Mts. Nine ages of the Cenozoic volcanic rocks from the basin by K-Ar isotope-dilution technique have been reported in the note. The apparent ages of whole rock and separated biotite range from 32.04 to 36.50 Ma. The 40Ar-K (%) correlation isochronal line shows that there existed neither argon excessing , nor radiogenetic argon loosing, i.e. the age represents the true diagenetic time. Volcanic activity in this area occurred in the post-collision environment and is controlled by lithosphere substantial thickening and violent intercontinental shearing-strike slip faults. There is age difference of the magmatic activity in the east, the west and the north Tibet. The multi-periodic eruption-intrusion of the magmatic melt since Cenozoic is a tracer showing the pulsating uplift of the Tibetan Plateau.展开更多
In southern Asia, there are three large-scale wave-like mountains ranging from the Tibetan Plateau westward to the Iranian Plateau and the Armenian Plateau. On the southern side between plateaus, there are the Indian ...In southern Asia, there are three large-scale wave-like mountains ranging from the Tibetan Plateau westward to the Iranian Plateau and the Armenian Plateau. On the southern side between plateaus, there are the Indian Peninsula and the Arabian Peninsula. What dynamic mechanisms form the directional alignment of the three plateaus with the two peninsulas remains a mystery. In the early stages of the Earth’s geological evolution, the internal structure of the Earth was that the center was a solid core, and the outmost layer was a thin equatorial crust zone separated by two thick pristine continents in polar areas, while the middle part was a deep magma fluid layer. Within the magma fluid layer, thermal and dynamic differences triggered planetary-scale vertical magma cells and led to the core-magma angular momentum exchange. When the core loses angular momentum and the magma layer gains angular momentum, the movement of upper magma fluids to the east and the tropical convergence zone (TCZ) drives the split and drift of two thick pristine continents, eventually forming the current combination of these plateaus and peninsulas and their wave-like arrangement along the east-west direction. Among them, the horizontal orthogonal convergence (collision) of upper magma fluids from the two hemispheres excited the vertical shear stress along the magma TCZ, which is the dynamic mechanism of mountain uplifts on the north side and plate subductions on the south side. To confirm this mechanism, two examples of low-level winds are used to calculate the correspondence between cyclone/anticyclonic systems generated by the orthogonal collision of airflows along the atmospheric TCZ and satellite-observed cloud systems. Such comparison can help us revisit the geological history of continental drift and orogeny.展开更多
By observing, measuring the fluvial sediment grain size of mid-western segment of the Qilianshan Range and studying the correlation between the grain size and uplift of the plateau, we model the correlation. These mod...By observing, measuring the fluvial sediment grain size of mid-western segment of the Qilianshan Range and studying the correlation between the grain size and uplift of the plateau, we model the correlation. These models are applied to the Laojunmiao section and the process curve of the uplift of the northern Tibetan Plateau against age from 8.35 Ma is illustrated here. The process curve shows that the northern Tibetan Plateau surface has uplifted from the mean altitude of 900-3700 m since 8.35 MaBP. From 8.35 to 3.1 MaBP, the Tibetan Plateau uplifted slowly, uplifted amplitude is small, the total range is 420 m. From 3.1 MaBP up to now, the Tibetan Plateau uplifted tempestuously, showing that the uplift accelerated obviously later. It uplifted totally 2400 m. About 0.9 Ma ago, the northern Tibetan Plateau surface had uplifted to over 3000 m a.s.l., showing that the Tibetan Plateau surface had reached the cryosphere; and the mountain peaks had uplifted to more than 4000 m altitude, suggesting that there was a glacier developed on the mountains.展开更多
文摘The Nangqen Basin is one of the typical shearing-extensional basins situated in the north part of the Hengduan Mts. Nine ages of the Cenozoic volcanic rocks from the basin by K-Ar isotope-dilution technique have been reported in the note. The apparent ages of whole rock and separated biotite range from 32.04 to 36.50 Ma. The 40Ar-K (%) correlation isochronal line shows that there existed neither argon excessing , nor radiogenetic argon loosing, i.e. the age represents the true diagenetic time. Volcanic activity in this area occurred in the post-collision environment and is controlled by lithosphere substantial thickening and violent intercontinental shearing-strike slip faults. There is age difference of the magmatic activity in the east, the west and the north Tibet. The multi-periodic eruption-intrusion of the magmatic melt since Cenozoic is a tracer showing the pulsating uplift of the Tibetan Plateau.
文摘In southern Asia, there are three large-scale wave-like mountains ranging from the Tibetan Plateau westward to the Iranian Plateau and the Armenian Plateau. On the southern side between plateaus, there are the Indian Peninsula and the Arabian Peninsula. What dynamic mechanisms form the directional alignment of the three plateaus with the two peninsulas remains a mystery. In the early stages of the Earth’s geological evolution, the internal structure of the Earth was that the center was a solid core, and the outmost layer was a thin equatorial crust zone separated by two thick pristine continents in polar areas, while the middle part was a deep magma fluid layer. Within the magma fluid layer, thermal and dynamic differences triggered planetary-scale vertical magma cells and led to the core-magma angular momentum exchange. When the core loses angular momentum and the magma layer gains angular momentum, the movement of upper magma fluids to the east and the tropical convergence zone (TCZ) drives the split and drift of two thick pristine continents, eventually forming the current combination of these plateaus and peninsulas and their wave-like arrangement along the east-west direction. Among them, the horizontal orthogonal convergence (collision) of upper magma fluids from the two hemispheres excited the vertical shear stress along the magma TCZ, which is the dynamic mechanism of mountain uplifts on the north side and plate subductions on the south side. To confirm this mechanism, two examples of low-level winds are used to calculate the correspondence between cyclone/anticyclonic systems generated by the orthogonal collision of airflows along the atmospheric TCZ and satellite-observed cloud systems. Such comparison can help us revisit the geological history of continental drift and orogeny.
基金the National Key Basic Research Project on the Tibetan Plateau (Grant No. G1998040809), the Hundred Talents Project of the CAS and the Project on Sci-Techology Research.
文摘By observing, measuring the fluvial sediment grain size of mid-western segment of the Qilianshan Range and studying the correlation between the grain size and uplift of the plateau, we model the correlation. These models are applied to the Laojunmiao section and the process curve of the uplift of the northern Tibetan Plateau against age from 8.35 Ma is illustrated here. The process curve shows that the northern Tibetan Plateau surface has uplifted from the mean altitude of 900-3700 m since 8.35 MaBP. From 8.35 to 3.1 MaBP, the Tibetan Plateau uplifted slowly, uplifted amplitude is small, the total range is 420 m. From 3.1 MaBP up to now, the Tibetan Plateau uplifted tempestuously, showing that the uplift accelerated obviously later. It uplifted totally 2400 m. About 0.9 Ma ago, the northern Tibetan Plateau surface had uplifted to over 3000 m a.s.l., showing that the Tibetan Plateau surface had reached the cryosphere; and the mountain peaks had uplifted to more than 4000 m altitude, suggesting that there was a glacier developed on the mountains.
