Regional metamorphic rocks preserve records of geodynamic evolution of orogenic belts.The Himalaya represents an evolving mountain belt with a complex geological history and is considered here as a composite of Trans...Regional metamorphic rocks preserve records of geodynamic evolution of orogenic belts.The Himalaya represents an evolving mountain belt with a complex geological history and is considered here as a composite of Trans–Himalaya and the Himalaya per se and the intervening Indus–Tsangpo Suture Zone.Each of these three tectonic domains is evaluated in the context of their metamorphic evolution.An episodic evolution is inferred and described.展开更多
In the Himalaya,distinct terranes are juxtaposed across the Main Central Thrust Zone(MCTZ)where subthrust Inner Lesser Himalaya(iLH)sedimentary belt yielded nearly unimodal U-Pb detrital zircon(DZ)between 2.05 and 1.8...In the Himalaya,distinct terranes are juxtaposed across the Main Central Thrust Zone(MCTZ)where subthrust Inner Lesser Himalaya(iLH)sedimentary belt yielded nearly unimodal U-Pb detrital zircon(DZ)between 2.05 and 1.80 Ga.Within this thrust zone,orthomylonite and other lithologies represent the Proterozoic magmatic arc with zircon having U-Pb~1.95 to 1.89 Ga crystallization ages;together,these represent the Columbian Supercontinent assembly.In contrast,first appearance of the Neoproterozoic 1.05-0.85 Ga zircon characterizes the overthrust Great Himalayan Sequence(GHS–Vaikrita Group)along the Main Central Thrust(MCT),while early Paleozoic detrital zirconhas first appearance in tectonically overlying Tethyan Himalayan Sequence(THS).展开更多
Introduction Geology of the Indian subcontinent is not only diverse and interesting but also has been studied for a long period.Reflection of a rich geoscientific heritage may be illustrated by a couple of lesser know...Introduction Geology of the Indian subcontinent is not only diverse and interesting but also has been studied for a long period.Reflection of a rich geoscientific heritage may be illustrated by a couple of lesser known early or first“discoveries/descriptions”from the Indian subcontinent.Heinrich(1966)in his book“The Geology of Carbonatites”mentions that the first description of carbonatite was provided from India by Bose(1884)as quoted below(italics and bold for emphasis).展开更多
The signature splitting observed in the 3/2[521]_(ν)↑⊗1/2[660]_(ν)↑⊗1/2[660]_(ν)↑three-quasineutron rotational band of 155 Dy is examined within the framework of axially symmetric three-quasiparticle plus axiall...The signature splitting observed in the 3/2[521]_(ν)↑⊗1/2[660]_(ν)↑⊗1/2[660]_(ν)↑three-quasineutron rotational band of 155 Dy is examined within the framework of axially symmetric three-quasiparticle plus axially symmetric rotor model.The experimental level energies and magnitudes of observed splitting are well-reproduced with RMS deviations of 68.13 keV and 0.58 keV,respectively.The major contributing bands in the observed splitting are K^(π)=7/2^(-):5/2[512]_(ν)↑⊗3/2[651]_(ν)↑⊗1/2[660]_(ν)↓,K^(π)=5/2^(-):5/2[512]_(ν)↑⊗3/2[651]_(ν)↑⊗3/2[651]_(ν)↓,K^(π)=1/2^(-):3/2[521]_(ν)↑⊗1/2[660]_(ν)↑⊗3/2[651]_(ν)↓,K^(π)=1/2^(-):3/2[521]_(ν)↓⊗1/2[660]_(ν)↑⊗3/2[651]_(ν)↑,K^(π)=5/2^(-):3/2[521]_(ν)↑⊗3/2[651]_(ν)↑⊗1/2[660]_(ν)↓,and K^(π)=3/2^(-):3/2[521]_(ν)↑⊗3/2[651]_(ν)↑⊗3/2[651]_(ν)↓,which mix through rotor-particle(ΔK=1)and particle-particle(ΔK=0)couplings among the bands comprising the given basis space.The observed signature splitting is also wellreproduced by the superposition of calculated energy staggering of the strongly interacting bands,which further strengthens the validity of present particle rotor model calculations.Based on the present calculations,we assign the bandhead spin K^(π)=3/2^(-)to the band under discussion.Additionally,the locations of 13 low-lying band members in the spin range I^(π)=3/2^(-)to 23/2^(-)and at 27/2^(-)and 31/2^(-)are predicted,which will be useful for future experimental investigations.展开更多
基金support of MoES funded project[‘Age Constraints on metamorphic evolution of the Trans-Himalayas’:‘MoES/P.O.(Geol/101(b)/2017)’]financial support under the INSA Honorary Scientist Program at the CSIR-Central Building research Institute,Roorkee.
文摘Regional metamorphic rocks preserve records of geodynamic evolution of orogenic belts.The Himalaya represents an evolving mountain belt with a complex geological history and is considered here as a composite of Trans–Himalaya and the Himalaya per se and the intervening Indus–Tsangpo Suture Zone.Each of these three tectonic domains is evaluated in the context of their metamorphic evolution.An episodic evolution is inferred and described.
文摘In the Himalaya,distinct terranes are juxtaposed across the Main Central Thrust Zone(MCTZ)where subthrust Inner Lesser Himalaya(iLH)sedimentary belt yielded nearly unimodal U-Pb detrital zircon(DZ)between 2.05 and 1.80 Ga.Within this thrust zone,orthomylonite and other lithologies represent the Proterozoic magmatic arc with zircon having U-Pb~1.95 to 1.89 Ga crystallization ages;together,these represent the Columbian Supercontinent assembly.In contrast,first appearance of the Neoproterozoic 1.05-0.85 Ga zircon characterizes the overthrust Great Himalayan Sequence(GHS–Vaikrita Group)along the Main Central Thrust(MCT),while early Paleozoic detrital zirconhas first appearance in tectonically overlying Tethyan Himalayan Sequence(THS).
文摘Introduction Geology of the Indian subcontinent is not only diverse and interesting but also has been studied for a long period.Reflection of a rich geoscientific heritage may be illustrated by a couple of lesser known early or first“discoveries/descriptions”from the Indian subcontinent.Heinrich(1966)in his book“The Geology of Carbonatites”mentions that the first description of carbonatite was provided from India by Bose(1884)as quoted below(italics and bold for emphasis).
基金Supported by Akal University,Talwandi Sabo,Bathinda,Punjab,India,International Atomic Energy Agency(IAEA),Vienna,Austria and DAE-BRNS,Government of India(Grant No.36(6)/14/60/2016-BRNS/36145)。
文摘The signature splitting observed in the 3/2[521]_(ν)↑⊗1/2[660]_(ν)↑⊗1/2[660]_(ν)↑three-quasineutron rotational band of 155 Dy is examined within the framework of axially symmetric three-quasiparticle plus axially symmetric rotor model.The experimental level energies and magnitudes of observed splitting are well-reproduced with RMS deviations of 68.13 keV and 0.58 keV,respectively.The major contributing bands in the observed splitting are K^(π)=7/2^(-):5/2[512]_(ν)↑⊗3/2[651]_(ν)↑⊗1/2[660]_(ν)↓,K^(π)=5/2^(-):5/2[512]_(ν)↑⊗3/2[651]_(ν)↑⊗3/2[651]_(ν)↓,K^(π)=1/2^(-):3/2[521]_(ν)↑⊗1/2[660]_(ν)↑⊗3/2[651]_(ν)↓,K^(π)=1/2^(-):3/2[521]_(ν)↓⊗1/2[660]_(ν)↑⊗3/2[651]_(ν)↑,K^(π)=5/2^(-):3/2[521]_(ν)↑⊗3/2[651]_(ν)↑⊗1/2[660]_(ν)↓,and K^(π)=3/2^(-):3/2[521]_(ν)↑⊗3/2[651]_(ν)↑⊗3/2[651]_(ν)↓,which mix through rotor-particle(ΔK=1)and particle-particle(ΔK=0)couplings among the bands comprising the given basis space.The observed signature splitting is also wellreproduced by the superposition of calculated energy staggering of the strongly interacting bands,which further strengthens the validity of present particle rotor model calculations.Based on the present calculations,we assign the bandhead spin K^(π)=3/2^(-)to the band under discussion.Additionally,the locations of 13 low-lying band members in the spin range I^(π)=3/2^(-)to 23/2^(-)and at 27/2^(-)and 31/2^(-)are predicted,which will be useful for future experimental investigations.
